From a21545a64cd61a7241ef1ffaa429750a8c6c2743 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Tue, 8 Nov 2022 09:40:49 -0800
Subject: [PATCH 01/14] Add type information here and there

---
 src/StripeResource.ts | 81 +++++++++++++++++++++++++++----------------
 src/makeRequest.ts    | 42 +++++++++++++++-------
 src/multipart.ts      | 13 +++++--
 src/stripe.ts         | 18 +++++-----
 src/utils.ts          | 58 +++++++++++++++++--------------
 5 files changed, 132 insertions(+), 80 deletions(-)

diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index e8f85599fe..551da2b02d 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -14,6 +14,7 @@ const {HttpClient} = require('./net/HttpClient');
 
 type Settings = {
   timeout?: number;
+  maxNetworkRetries?: number;
 };
 
 type Options = {
@@ -35,7 +36,7 @@ const MAX_RETRY_AFTER_WAIT = 60;
 /**
  * Encapsulates request logic for a Stripe Resource
  */
-function StripeResource(stripe, deprecatedUrlData) {
+function StripeResource(stripe, deprecatedUrlData?: never) {
   this._stripe = stripe;
   if (deprecatedUrlData) {
     throw new Error(
@@ -78,7 +79,10 @@ StripeResource.prototype = {
   // be thrown, and they will be passed to the callback/promise.
   validateRequest: null,
 
-  createFullPath(commandPath, urlData) {
+  createFullPath(
+    commandPath: string | ((urlData: Record<string, unknown>) => string),
+    urlData: Record<string, unknown>
+  ) {
     const urlParts = [this.basePath(urlData), this.path(urlData)];
 
     if (typeof commandPath === 'function') {
@@ -99,7 +103,7 @@ StripeResource.prototype = {
   // Creates a relative resource path with symbols left in (unlike
   // createFullPath which takes some data to replace them with). For example it
   // might produce: /invoices/{id}
-  createResourcePathWithSymbols(pathWithSymbols) {
+  createResourcePathWithSymbols(pathWithSymbols: string) {
     // If there is no path beyond the resource path, we want to produce just
     // /<resource path> rather than /<resource path>/.
     if (pathWithSymbols) {
@@ -109,7 +113,7 @@ StripeResource.prototype = {
     }
   },
 
-  _joinUrlParts(parts) {
+  _joinUrlParts(parts: Array<string>) {
     // Replace any accidentally doubled up slashes. This previously used
     // path.join, which would do this as well. Unfortunately we need to do this
     // as the functions for creating paths are technically part of the public
@@ -129,7 +133,10 @@ StripeResource.prototype = {
     };
   },
 
-  _addHeadersDirectlyToObject(obj, headers) {
+  _addHeadersDirectlyToObject(
+    obj: Record<string, unknown>,
+    headers: Record<string, unknown>
+  ) {
     // For convenience, make some headers easily accessible on
     // lastResponse.
 
@@ -140,7 +147,11 @@ StripeResource.prototype = {
     obj.idempotencyKey = obj.idempotencyKey || headers['idempotency-key'];
   },
 
-  _makeResponseEvent(requestEvent, statusCode, headers) {
+  _makeResponseEvent(
+    requestEvent,
+    statusCode: number,
+    headers: Record<string, unknown>
+  ) {
     const requestEndTime = Date.now();
     const requestDurationMs = requestEndTime - requestEvent.request_start_time;
 
@@ -158,7 +169,7 @@ StripeResource.prototype = {
     });
   },
 
-  _getRequestId(headers) {
+  _getRequestId(headers: Record<string, unknown>) {
     return headers['request-id'];
   },
 
@@ -301,7 +312,7 @@ StripeResource.prototype = {
   },
 
   // For more on when and how to retry API requests, see https://stripe.com/docs/error-handling#safely-retrying-requests-with-idempotency
-  _shouldRetry(res, numRetries, maxRetries, error) {
+  _shouldRetry(res, numRetries: number, maxRetries: number, error?) {
     if (
       error &&
       numRetries === 0 &&
@@ -346,7 +357,7 @@ StripeResource.prototype = {
     return false;
   },
 
-  _getSleepTimeInMS(numRetries, retryAfter = null) {
+  _getSleepTimeInMS(numRetries: number, retryAfter: number | null = null) {
     const initialNetworkRetryDelay = this._stripe.getInitialNetworkRetryDelay();
     const maxNetworkRetryDelay = this._stripe.getMaxNetworkRetryDelay();
 
@@ -374,14 +385,14 @@ StripeResource.prototype = {
   },
 
   // Max retries can be set on a per request basis. Favor those over the global setting
-  _getMaxNetworkRetries(settings: {maxNetworkRetries?: number} = {}) {
+  _getMaxNetworkRetries(settings: Settings = {}) {
     return settings.maxNetworkRetries &&
       Number.isInteger(settings.maxNetworkRetries)
       ? settings.maxNetworkRetries
       : this._stripe.getMaxNetworkRetries();
   },
 
-  _defaultIdempotencyKey(method, settings) {
+  _defaultIdempotencyKey(method: string, settings: Settings) {
     // If this is a POST and we allow multiple retries, ensure an idempotency key.
     const maxRetries = this._getMaxNetworkRetries(settings);
 
@@ -392,14 +403,14 @@ StripeResource.prototype = {
   },
 
   _makeHeaders(
-    auth,
-    contentLength,
-    apiVersion,
-    clientUserAgent,
-    method,
-    userSuppliedHeaders,
-    userSuppliedSettings
-  ) {
+    auth: string,
+    contentLength: number,
+    apiVersion: string,
+    clientUserAgent: string,
+    method: string,
+    userSuppliedHeaders: Record<string, unknown>,
+    userSuppliedSettings: Settings
+  ): Record<string, unknown> {
     const defaultHeaders = {
       // Use specified auth token or use default from this stripe instance:
       Authorization: auth ? `Bearer ${auth}` : this._stripe.getApiField('auth'),
@@ -451,7 +462,7 @@ StripeResource.prototype = {
     );
   },
 
-  _getUserAgentString() {
+  _getUserAgentString(): string {
     const packageVersion = this._stripe.getConstant('PACKAGE_VERSION');
     const appInfo = this._stripe._appInfo
       ? this._stripe.getAppInfoAsString()
@@ -460,7 +471,7 @@ StripeResource.prototype = {
     return `Stripe/v1 NodeBindings/${packageVersion} ${appInfo}`.trim();
   },
 
-  _getTelemetryHeader() {
+  _getTelemetryHeader(): string {
     if (
       this._stripe.getTelemetryEnabled() &&
       this._stripe._prevRequestMetrics.length > 0
@@ -472,7 +483,7 @@ StripeResource.prototype = {
     }
   },
 
-  _recordRequestMetrics(requestId, requestDurationMs) {
+  _recordRequestMetrics(requestId, requestDurationMs): void {
     if (this._stripe.getTelemetryEnabled() && requestId) {
       if (
         this._stripe._prevRequestMetrics.length >
@@ -490,15 +501,23 @@ StripeResource.prototype = {
     }
   },
 
-  _request(method, host, path, data, auth, options: Options = {}, callback) {
+  _request(
+    method: string,
+    host: string,
+    path: string,
+    data: unknown,
+    auth: string,
+    options: Options = {},
+    callback
+  ) {
     let requestData;
 
     const retryRequest = (
-      requestFn,
-      apiVersion,
-      headers,
-      requestRetries,
-      retryAfter
+      requestFn: typeof makeRequest,
+      apiVersion: string,
+      headers: Record<string, unknown>,
+      requestRetries: number,
+      retryAfter: number | null
     ) => {
       return setTimeout(
         requestFn,
@@ -509,7 +528,11 @@ StripeResource.prototype = {
       );
     };
 
-    const makeRequest = (apiVersion, headers, numRetries) => {
+    const makeRequest = (
+      apiVersion: string,
+      headers: Record<string, unknown>,
+      numRetries: number
+    ) => {
       // timeout can be set on a per-request basis. Favor that over the global setting
       const timeout =
         options.settings &&
diff --git a/src/makeRequest.ts b/src/makeRequest.ts
index 57737cfd25..515f253e77 100644
--- a/src/makeRequest.ts
+++ b/src/makeRequest.ts
@@ -1,6 +1,21 @@
 const utils = require('./utils');
 
-function getRequestOpts(self, requestArgs, spec, overrideData) {
+type MethodSpec = {
+  method: string;
+  urlParams: Array<string>;
+  path?: string;
+  fullPath?: string;
+  encode: (data: Record<string, unknown>) => Record<string, unknown>;
+  validator: (
+    data: Record<string, unknown>,
+    headers: Record<string, string>
+  ) => void;
+  headers: Record<string, string>;
+  streaming?: boolean;
+  host?: string;
+};
+
+function getRequestOpts(self, requestArgs, spec: MethodSpec, overrideData) {
   // Extract spec values with defaults.
   const requestMethod = (spec.method || 'GET').toUpperCase();
   const urlParams = spec.urlParams || [];
@@ -20,17 +35,20 @@ function getRequestOpts(self, requestArgs, spec, overrideData) {
   const args = [].slice.call(requestArgs);
 
   // Generate and validate url params.
-  const urlData = urlParams.reduce((urlData, param) => {
-    const arg = args.shift();
-    if (typeof arg !== 'string') {
-      throw new Error(
-        `Stripe: Argument "${param}" must be a string, but got: ${arg} (on API request to \`${requestMethod} ${path}\`)`
-      );
-    }
+  const urlData = urlParams.reduce<Record<string, unknown>>(
+    (urlData, param) => {
+      const arg = args.shift();
+      if (typeof arg !== 'string') {
+        throw new Error(
+          `Stripe: Argument "${param}" must be a string, but got: ${arg} (on API request to \`${requestMethod} ${path}\`)`
+        );
+      }
 
-    urlData[param] = arg;
-    return urlData;
-  }, {});
+      urlData[param] = arg;
+      return urlData;
+    },
+    {}
+  );
 
   // Pull request data and options (headers, auth) from args.
   const dataFromArgs = utils.getDataFromArgs(args);
@@ -84,7 +102,7 @@ function makeRequest(self, requestArgs, spec, overrideData) {
       return;
     }
 
-    function requestCallback(err, response) {
+    function requestCallback(err: any, response) {
       if (err) {
         reject(err);
       } else {
diff --git a/src/multipart.ts b/src/multipart.ts
index dbb59a8bcf..96b57868f2 100644
--- a/src/multipart.ts
+++ b/src/multipart.ts
@@ -33,14 +33,21 @@ const multipartDataGenerator = (method, data, headers) => {
     const v = flattenedData[k];
     push(`--${segno}`);
     if (Object.prototype.hasOwnProperty.call(v, 'data')) {
+      // eslint-disable-next-line no-warning-comments
+      // TODO: I don't think we ever hit this branch
+      const typedEntry: {
+        name: string;
+        data: string;
+        type: string;
+      } = v as any;
       push(
         `Content-Disposition: form-data; name=${q(k)}; filename=${q(
-          v.name || 'blob'
+          typedEntry.name || 'blob'
         )}`
       );
-      push(`Content-Type: ${v.type || 'application/octet-stream'}`);
+      push(`Content-Type: ${typedEntry.type || 'application/octet-stream'}`);
       push('');
-      push(v.data);
+      push(typedEntry.data);
     } else {
       push(`Content-Disposition: form-data; name=${q(k)}`);
       push('');
diff --git a/src/stripe.ts b/src/stripe.ts
index 5d6cb7e377..25ff85625a 100644
--- a/src/stripe.ts
+++ b/src/stripe.ts
@@ -1,4 +1,5 @@
 import _Error = require('./Error');
+import StripeResource = require('./StripeResource');
 
 const resources = require('./resources');
 
@@ -47,7 +48,6 @@ const ALLOWED_CONFIG_PROPERTIES = [
 
 const EventEmitter = require('events').EventEmitter;
 
-import StripeResource = require('./StripeResource');
 Stripe.StripeResource = StripeResource;
 Stripe.resources = resources;
 
@@ -327,7 +327,7 @@ Stripe.prototype = {
 
     info = info || {};
 
-    const appInfo = APP_INFO_PROPERTIES.reduce(
+    this._appInfo = APP_INFO_PROPERTIES.reduce(
       (accum: Record<string, any>, prop) => {
         if (typeof info[prop] == 'string') {
           accum = accum || {};
@@ -339,8 +339,6 @@ Stripe.prototype = {
       },
       undefined
     );
-
-    this._appInfo = appInfo;
   },
 
   /**
@@ -374,15 +372,15 @@ Stripe.prototype = {
    *
    * It may be deprecated and removed in the future.
    */
-  getApiField(key) {
+  getApiField(key: string): unknown {
     return this._api[key];
   },
 
-  setClientId(clientId) {
+  setClientId(clientId: string): void {
     this._clientId = clientId;
   },
 
-  getClientId() {
+  getClientId(): string {
     return this._clientId;
   },
 
@@ -413,7 +411,7 @@ Stripe.prototype = {
     return Stripe[c];
   },
 
-  getMaxNetworkRetries() {
+  getMaxNetworkRetries(): number {
     return this.getApiField('maxNetworkRetries');
   },
 
@@ -425,7 +423,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setMaxNetworkRetries(maxNetworkRetries) {
+  setMaxNetworkRetries(maxNetworkRetries: number) {
     this._setApiNumberField('maxNetworkRetries', maxNetworkRetries);
   },
 
@@ -433,7 +431,7 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _setApiNumberField(prop, n, defaultVal) {
+  _setApiNumberField(prop: string, n: number, defaultVal?: number) {
     const val = utils.validateInteger(prop, n, defaultVal);
 
     this._setApiField(prop, val);
diff --git a/src/utils.ts b/src/utils.ts
index b3ac274cbc..d3bcc8f997 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -43,11 +43,11 @@ type Options = {
   host?: string;
   settings?: Settings;
   streaming?: boolean;
-  headers?: Record<string, string>;
+  headers?: Record<string, unknown>;
 };
 
 const utils = {
-  isOptionsHash(o) {
+  isOptionsHash(o: unknown): boolean {
     return (
       o &&
       typeof o === 'object' &&
@@ -64,7 +64,7 @@ const utils = {
    * Stringifies an Object, accommodating nested objects
    * (forming the conventional key 'parent[child]=value')
    */
-  stringifyRequestData: (data) => {
+  stringifyRequestData: (data: unknown): string => {
     return (
       qs
         .stringify(data, {
@@ -101,7 +101,7 @@ const utils = {
     };
   })(),
 
-  extractUrlParams: (path) => {
+  extractUrlParams: (path: string): Array<string> => {
     const params = path.match(/\{\w+\}/g);
     if (!params) {
       return [];
@@ -116,7 +116,7 @@ const utils = {
    * @param {object[]} args
    * @returns {object}
    */
-  getDataFromArgs(args) {
+  getDataFromArgs(args: Array<unknown>): Record<string, unknown> {
     if (!Array.isArray(args) || !args[0] || typeof args[0] !== 'object') {
       return {};
     }
@@ -152,7 +152,7 @@ const utils = {
   /**
    * Return the options hash from a list of arguments
    */
-  getOptionsFromArgs: (args) => {
+  getOptionsFromArgs: (args: Array<unknown>): Options => {
     const opts: Options = {
       auth: null,
       headers: {},
@@ -161,9 +161,10 @@ const utils = {
     if (args.length > 0) {
       const arg = args[args.length - 1];
       if (typeof arg === 'string') {
-        opts.auth = args.pop();
+        args.pop();
+        opts.auth = arg;
       } else if (utils.isOptionsHash(arg)) {
-        const params = {...args.pop()};
+        const params = {...(arg as Record<string, unknown>)};
 
         const extraKeys = Object.keys(params).filter(
           (key) => !OPTIONS_KEYS.includes(key)
@@ -194,7 +195,7 @@ const utils = {
         }
 
         if (params.apiKey) {
-          opts.auth = params.apiKey;
+          opts.auth = params.apiKey as string;
         }
         if (params.idempotencyKey) {
           opts.headers['Idempotency-Key'] = params.idempotencyKey;
@@ -206,13 +207,13 @@ const utils = {
           opts.headers['Stripe-Version'] = params.apiVersion;
         }
         if (Number.isInteger(params.maxNetworkRetries)) {
-          opts.settings.maxNetworkRetries = params.maxNetworkRetries;
+          opts.settings.maxNetworkRetries = params.maxNetworkRetries as number;
         }
         if (Number.isInteger(params.timeout)) {
-          opts.settings.timeout = params.timeout;
+          opts.settings.timeout = params.timeout as number;
         }
         if (params.host) {
-          opts.host = params.host;
+          opts.host = params.host as string;
         }
       }
     }
@@ -246,7 +247,7 @@ const utils = {
   /**
    * Secure compare, from https://github.com/freewil/scmp
    */
-  secureCompare: (a, b) => {
+  secureCompare: (a: Uint8Array, b: Uint8Array): boolean => {
     a = Buffer.from(a);
     b = Buffer.from(b);
 
@@ -274,7 +275,7 @@ const utils = {
   /**
    * Remove empty values from an object
    */
-  removeNullish: (obj) => {
+  removeNullish: (obj: Record<string, unknown>): Record<string, unknown> => {
     if (typeof obj !== 'object') {
       throw new Error('Argument must be an object');
     }
@@ -293,7 +294,7 @@ const utils = {
    * becomes
    * {'Foo-Bar': 'hi'}
    */
-  normalizeHeaders: (obj) => {
+  normalizeHeaders: (obj: Record<string, unknown>): Record<string, unknown> => {
     if (!(obj && typeof obj === 'object')) {
       return obj;
     }
@@ -308,7 +309,7 @@ const utils = {
    * Stolen from https://github.com/marten-de-vries/header-case-normalizer/blob/master/index.js#L36-L41
    * without the exceptions which are irrelevant to us.
    */
-  normalizeHeader: (header) => {
+  normalizeHeader: (header: string): string => {
     return header
       .split('-')
       .map(
@@ -328,7 +329,10 @@ const utils = {
     return false;
   },
 
-  callbackifyPromiseWithTimeout: (promise, callback) => {
+  callbackifyPromiseWithTimeout: <T>(
+    promise: Promise<T>,
+    callback: (error: unknown, result: T) => void
+  ): Promise<T | void> => {
     if (callback) {
       // Ensure callback is called outside of promise stack.
       return promise.then(
@@ -351,7 +355,7 @@ const utils = {
   /**
    * Allow for special capitalization cases (such as OAuth)
    */
-  pascalToCamelCase: (name) => {
+  pascalToCamelCase: (name: string): string => {
     if (name === 'OAuth') {
       return 'oauth';
     } else {
@@ -368,7 +372,7 @@ const utils = {
    *
    * This unifies that interface.
    */
-  safeExec: (cmd, cb) => {
+  safeExec: (cmd: string, cb: (error: Error, stdout: string) => void): void => {
     // Occurs if we couldn't load the `child_process` module, which might
     // happen in certain sandboxed environments like a CloudFlare Worker.
     if (utils._exec === null) {
@@ -386,13 +390,15 @@ const utils = {
   // For mocking in tests.
   _exec: exec,
 
-  isObject: (obj) => {
+  isObject: (obj: unknown): boolean => {
     const type = typeof obj;
     return (type === 'function' || type === 'object') && !!obj;
   },
 
   // For use in multipart requests
-  flattenAndStringify: (data) => {
+  flattenAndStringify: (
+    data: Record<string, unknown>
+  ): Record<string, unknown> => {
     const result = {};
 
     const step = (obj, prevKey) => {
@@ -427,7 +433,7 @@ const utils = {
   /**
    * https://stackoverflow.com/a/2117523
    */
-  uuid4: () => {
+  uuid4: (): string => {
     return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
       const r = (Math.random() * 16) | 0;
       const v = c === 'x' ? r : (r & 0x3) | 0x8;
@@ -435,7 +441,7 @@ const utils = {
     });
   },
 
-  validateInteger: (name, n, defaultVal) => {
+  validateInteger: (name: string, n: unknown, defaultVal?: number): number => {
     if (!Number.isInteger(n)) {
       if (defaultVal !== undefined) {
         return defaultVal;
@@ -444,10 +450,10 @@ const utils = {
       }
     }
 
-    return n;
+    return n as number;
   },
 
-  determineProcessUserAgentProperties: () => {
+  determineProcessUserAgentProperties: (): Record<string, string> => {
     return typeof process === 'undefined'
       ? {}
       : {
@@ -457,7 +463,7 @@ const utils = {
   },
 };
 
-function emitWarning(warning) {
+function emitWarning(warning: string): void {
   if (typeof process.emitWarning !== 'function') {
     return console.warn(
       `Stripe: ${warning}`

From e9ce7f2779c4bf3cfbbd6901990ae7aeba63e42f Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Tue, 8 Nov 2022 09:50:40 -0800
Subject: [PATCH 02/14] reduce diff

---
 src/utils.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/utils.ts b/src/utils.ts
index 0648f3a7aa..82071907e8 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -161,10 +161,9 @@ const utils = {
     if (args.length > 0) {
       const arg = args[args.length - 1];
       if (typeof arg === 'string') {
-        args.pop();
-        opts.auth = arg;
+        opts.auth = args.pop() as string;
       } else if (utils.isOptionsHash(arg)) {
-        const params = {...(arg as Record<string, unknown>)};
+        const params = {...(args.pop() as Record<string, unknown>)};
 
         const extraKeys = Object.keys(params).filter(
           (key) => !OPTIONS_KEYS.includes(key)

From 7933b16dd4436471c1dc22ad047a043338332525 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Tue, 8 Nov 2022 10:10:15 -0800
Subject: [PATCH 03/14] more

---
 lib/multipart.js | 9 ++++++---
 lib/stripe.js    | 5 ++---
 src/utils.ts     | 2 +-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/lib/multipart.js b/lib/multipart.js
index d88d468b1f..cf7f6d9e53 100644
--- a/lib/multipart.js
+++ b/lib/multipart.js
@@ -28,14 +28,17 @@ const multipartDataGenerator = (method, data, headers) => {
     const v = flattenedData[k];
     push(`--${segno}`);
     if (Object.prototype.hasOwnProperty.call(v, 'data')) {
+      // eslint-disable-next-line no-warning-comments
+      // TODO: I don't think we ever hit this branch
+      const typedEntry = v;
       push(
         `Content-Disposition: form-data; name=${q(k)}; filename=${q(
-          v.name || 'blob'
+          typedEntry.name || 'blob'
         )}`
       );
-      push(`Content-Type: ${v.type || 'application/octet-stream'}`);
+      push(`Content-Type: ${typedEntry.type || 'application/octet-stream'}`);
       push('');
-      push(v.data);
+      push(typedEntry.data);
     } else {
       push(`Content-Disposition: form-data; name=${q(k)}`);
       push('');
diff --git a/lib/stripe.js b/lib/stripe.js
index 60b82e7312..b0b3f748e8 100644
--- a/lib/stripe.js
+++ b/lib/stripe.js
@@ -1,5 +1,6 @@
 'use strict';
 const _Error = require('./Error');
+const StripeResource = require('./StripeResource');
 const resources = require('./resources');
 const DEFAULT_HOST = 'api.stripe.com';
 const DEFAULT_PORT = '443';
@@ -39,7 +40,6 @@ const ALLOWED_CONFIG_PROPERTIES = [
   'stripeAccount',
 ];
 const EventEmitter = require('events').EventEmitter;
-const StripeResource = require('./StripeResource');
 Stripe.StripeResource = StripeResource;
 Stripe.resources = resources;
 const {HttpClient, HttpClientResponse} = require('./net/HttpClient');
@@ -286,14 +286,13 @@ Stripe.prototype = {
       throw new Error('AppInfo.name is required');
     }
     info = info || {};
-    const appInfo = APP_INFO_PROPERTIES.reduce((accum, prop) => {
+    this._appInfo = APP_INFO_PROPERTIES.reduce((accum, prop) => {
       if (typeof info[prop] == 'string') {
         accum = accum || {};
         accum[prop] = info[prop];
       }
       return accum;
     }, undefined);
-    this._appInfo = appInfo;
   },
   /**
    * @deprecated will be removed in a future major version. Use the config object instead:
diff --git a/src/utils.ts b/src/utils.ts
index 82071907e8..7832722810 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -321,7 +321,7 @@ const utils = {
    * Determine if file data is a derivative of EventEmitter class.
    * https://nodejs.org/api/events.html#events_events
    */
-  checkForStream: (obj) => {
+  checkForStream: (obj): boolean => {
     if (obj.file && obj.file.data) {
       return obj.file.data instanceof EventEmitter;
     }

From 4d30ef1ab246c26ef9c4e958d3f2de833102d370 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Tue, 8 Nov 2022 10:11:30 -0800
Subject: [PATCH 04/14] more

---
 lib/stripe.js | 2 +-
 src/stripe.ts | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/stripe.js b/lib/stripe.js
index b0b3f748e8..fc1e5bc95e 100644
--- a/lib/stripe.js
+++ b/lib/stripe.js
@@ -1,6 +1,5 @@
 'use strict';
 const _Error = require('./Error');
-const StripeResource = require('./StripeResource');
 const resources = require('./resources');
 const DEFAULT_HOST = 'api.stripe.com';
 const DEFAULT_PORT = '443';
@@ -40,6 +39,7 @@ const ALLOWED_CONFIG_PROPERTIES = [
   'stripeAccount',
 ];
 const EventEmitter = require('events').EventEmitter;
+const StripeResource = require('./StripeResource');
 Stripe.StripeResource = StripeResource;
 Stripe.resources = resources;
 const {HttpClient, HttpClientResponse} = require('./net/HttpClient');
diff --git a/src/stripe.ts b/src/stripe.ts
index 25ff85625a..c9f8784f25 100644
--- a/src/stripe.ts
+++ b/src/stripe.ts
@@ -1,5 +1,4 @@
 import _Error = require('./Error');
-import StripeResource = require('./StripeResource');
 
 const resources = require('./resources');
 
@@ -47,7 +46,7 @@ const ALLOWED_CONFIG_PROPERTIES = [
 ];
 
 const EventEmitter = require('events').EventEmitter;
-
+import StripeResource = require('./StripeResource');
 Stripe.StripeResource = StripeResource;
 Stripe.resources = resources;
 

From 6fb008c1dfd465f805b3958bbfcd2c3b2089e539 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 08:29:02 -0800
Subject: [PATCH 05/14] type webhooks

---
 src/Error.ts              |  2 +-
 src/Types.d.ts            |  4 ++
 src/Webhooks.ts           | 97 +++++++++++++++++++++++++++------------
 src/multipart.ts          | 16 +++++--
 src/net/NodeHttpClient.ts | 16 +++----
 src/utils.ts              | 14 +++---
 tsconfig.json             |  1 +
 7 files changed, 102 insertions(+), 48 deletions(-)
 create mode 100644 src/Types.d.ts

diff --git a/src/Error.ts b/src/Error.ts
index fbf88cc5d6..3e5078236c 100644
--- a/src/Error.ts
+++ b/src/Error.ts
@@ -83,7 +83,7 @@ class StripeError extends Error {
   /**
    * Helper factory which takes raw stripe errors and outputs wrapping instances
    */
-  static generate(rawStripeError) {
+  static generate(rawStripeError: StripeRawError) {
     switch (rawStripeError.type) {
       case 'card_error':
         return new StripeCardError(rawStripeError);
diff --git a/src/Types.d.ts b/src/Types.d.ts
new file mode 100644
index 0000000000..beac628435
--- /dev/null
+++ b/src/Types.d.ts
@@ -0,0 +1,4 @@
+type StripeResourceObject = {};
+
+type HttpHeaders = Record<string, string | number | string[]>;
+type RequestData = Record<string, unknown>;
diff --git a/src/Webhooks.ts b/src/Webhooks.ts
index 14d5a4ed8f..1381f03c23 100644
--- a/src/Webhooks.ts
+++ b/src/Webhooks.ts
@@ -2,11 +2,41 @@ import utils = require('./utils');
 import _Error = require('./Error');
 const {StripeError, StripeSignatureVerificationError} = _Error;
 
+type StripeCryptoProvider = {
+  computeHMACSignature: (data: string, secret: string) => string;
+  computeHMACSignatureAsync: (data: string, secret: string) => Promise<string>;
+};
+
+type WebhookPayload = string | Buffer;
+type WebhookHeader = string | Buffer;
+type WebhookParsedHeader = {
+  signatures: Array<string>;
+  timestamp: number;
+};
+type WebhookParsedEvent = {
+  details: WebhookParsedHeader;
+  decodedPayload: string;
+  decodedHeader: string;
+};
+type WebhookTestHeaderOptions = {
+  timestamp: number;
+  payload: string;
+  secret: string;
+  scheme: string;
+  signature: string;
+  cryptoProvider: StripeCryptoProvider;
+};
 const Webhook = {
   DEFAULT_TOLERANCE: 300, // 5 minutes
-  signature: null,
-
-  constructEvent(payload, header, secret, tolerance, cryptoProvider) {
+  signature: null as typeof signature,
+
+  constructEvent(
+    payload: WebhookPayload,
+    header: WebhookHeader,
+    secret: string,
+    tolerance: null,
+    cryptoProvider: StripeCryptoProvider
+  ) {
     this.signature.verifyHeader(
       payload,
       header,
@@ -15,16 +45,17 @@ const Webhook = {
       cryptoProvider
     );
 
+    // @ts-ignore
     const jsonPayload = JSON.parse(payload);
     return jsonPayload;
   },
 
   async constructEventAsync(
-    payload,
-    header,
-    secret,
-    tolerance,
-    cryptoProvider
+    payload: WebhookPayload,
+    header: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
   ) {
     await this.signature.verifyHeaderAsync(
       payload,
@@ -34,6 +65,7 @@ const Webhook = {
       cryptoProvider
     );
 
+    // @ts-ignore
     const jsonPayload = JSON.parse(payload);
     return jsonPayload;
   },
@@ -49,7 +81,7 @@ const Webhook = {
    * @property {string} signature - Computed webhook signature
    * @property {CryptoProvider} cryptoProvider - Crypto provider to use for computing the signature if none was provided. Defaults to NodeCryptoProvider.
    */
-  generateTestHeaderString: function(opts) {
+  generateTestHeaderString: function(opts: WebhookTestHeaderOptions) {
     if (!opts) {
       throw new StripeError({
         message: 'Options are required',
@@ -82,11 +114,11 @@ const signature = {
   EXPECTED_SCHEME: 'v1',
 
   verifyHeader(
-    encodedPayload,
-    encodedHeader,
-    secret,
-    tolerance,
-    cryptoProvider
+    encodedPayload: WebhookPayload,
+    encodedHeader: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
   ) {
     const {
       decodedHeader: header,
@@ -112,11 +144,11 @@ const signature = {
   },
 
   async verifyHeaderAsync(
-    encodedPayload,
-    encodedHeader,
-    secret,
-    tolerance,
-    cryptoProvider
+    encodedPayload: WebhookPayload,
+    encodedHeader: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
   ) {
     const {
       decodedHeader: header,
@@ -141,11 +173,18 @@ const signature = {
   },
 };
 
-function makeHMACContent(payload, details) {
+function makeHMACContent(
+  payload: WebhookPayload,
+  details: WebhookParsedHeader
+) {
   return `${details.timestamp}.${payload}`;
 }
 
-function parseEventDetails(encodedPayload, encodedHeader, expectedScheme) {
+function parseEventDetails(
+  encodedPayload: WebhookPayload,
+  encodedHeader: WebhookHeader,
+  expectedScheme: string
+): WebhookParsedEvent {
   const decodedPayload = Buffer.isBuffer(encodedPayload)
     ? encodedPayload.toString('utf8')
     : encodedPayload;
@@ -196,11 +235,11 @@ function parseEventDetails(encodedPayload, encodedHeader, expectedScheme) {
 }
 
 function validateComputedSignature(
-  payload,
-  header,
-  details,
-  expectedSignature,
-  tolerance
+  payload: WebhookPayload,
+  header: string,
+  details: WebhookParsedHeader,
+  expectedSignature: string,
+  tolerance: number
 ) {
   const signatureFound = !!details.signatures.filter(
     utils.secureCompare.bind(utils, expectedSignature)
@@ -236,7 +275,7 @@ function validateComputedSignature(
   return true;
 }
 
-function parseHeader(header, scheme) {
+function parseHeader(header: string, scheme: string): WebhookParsedHeader {
   if (typeof header !== 'string') {
     return null;
   }
@@ -262,13 +301,13 @@ function parseHeader(header, scheme) {
   );
 }
 
-let webhooksNodeCryptoProviderInstance = null;
+let webhooksNodeCryptoProviderInstance = null as StripeCryptoProvider;
 
 /**
  * Lazily instantiate a NodeCryptoProvider instance. This is a stateless object
  * so a singleton can be used here.
  */
-function getNodeCryptoProvider() {
+function getNodeCryptoProvider(): StripeCryptoProvider {
   if (!webhooksNodeCryptoProviderInstance) {
     const NodeCryptoProvider = require('./crypto/NodeCryptoProvider');
     webhooksNodeCryptoProviderInstance = new NodeCryptoProvider();
diff --git a/src/multipart.ts b/src/multipart.ts
index 96b57868f2..cff39bbd99 100644
--- a/src/multipart.ts
+++ b/src/multipart.ts
@@ -14,7 +14,7 @@ const multipartDataGenerator = (method, data, headers) => {
   headers['Content-Type'] = `multipart/form-data; boundary=${segno}`;
   let buffer = Buffer.alloc(0);
 
-  function push(l) {
+  function push(l: Buffer | string) {
     const prevBuffer = buffer;
     const newBuffer = l instanceof Buffer ? l : Buffer.from(l);
     buffer = Buffer.alloc(prevBuffer.length + newBuffer.length + 2);
@@ -59,7 +59,12 @@ const multipartDataGenerator = (method, data, headers) => {
   return buffer;
 };
 
-const streamProcessor = (method, data, headers, callback) => {
+const streamProcessor = (
+  method: string,
+  data: RequestData,
+  headers: HttpHeaders,
+  callback
+) => {
   const bufferArray = [];
   data.file.data
     .on('data', (line) => {
@@ -83,7 +88,12 @@ const streamProcessor = (method, data, headers, callback) => {
     });
 };
 
-const multipartRequestDataProcessor = (method, data, headers, callback) => {
+const multipartRequestDataProcessor = (
+  method: string,
+  data: RequestData,
+  headers: HttpHeaders,
+  callback
+) => {
   data = data || {};
 
   if (method !== 'POST') {
diff --git a/src/net/NodeHttpClient.ts b/src/net/NodeHttpClient.ts
index 1d556a0906..eff3e7fb9d 100644
--- a/src/net/NodeHttpClient.ts
+++ b/src/net/NodeHttpClient.ts
@@ -25,14 +25,14 @@ class NodeHttpClient extends HttpClient {
   }
 
   makeRequest(
-    host,
-    port,
-    path,
-    method,
-    headers,
-    requestData,
-    protocol,
-    timeout
+    host: string,
+    port: string,
+    path: string,
+    method: string,
+    headers: HttpHeaders,
+    requestData: Record<string, unknown>,
+    protocol: string,
+    timeout: number
   ) {
     const isInsecureConnection = protocol === 'http';
 
diff --git a/src/utils.ts b/src/utils.ts
index 7832722810..da5d652115 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -30,7 +30,7 @@ const DEPRECATED_OPTIONS = {
   stripe_account: 'stripeAccount',
   stripe_version: 'apiVersion',
   stripeVersion: 'apiVersion',
-};
+} as Record<string, string>;
 const DEPRECATED_OPTIONS_KEYS = Object.keys(DEPRECATED_OPTIONS);
 
 type Settings = {
@@ -68,7 +68,7 @@ const utils = {
     return (
       qs
         .stringify(data, {
-          serializeDate: (d) => Math.floor(d.getTime() / 1000),
+          serializeDate: (d: Date) => Math.floor(d.getTime() / 1000),
         })
         // Don't use strict form encoding by changing the square bracket control
         // characters back to their literals. This is fine by the server, and
@@ -90,10 +90,10 @@ const utils = {
       '"': '\\"',
       '\u2028': '\\u2028',
       '\u2029': '\\u2029',
-    };
-    return (str) => {
+    } as Record<string, string>;
+    return (str: string) => {
       const cleanString = str.replace(/["\n\r\u2028\u2029]/g, ($0) => rc[$0]);
-      return (outputs) => {
+      return (outputs: Record<string, undefined>) => {
         return cleanString.replace(/\{([\s\S]+?)\}/g, ($0, $1) =>
           encodeURIComponent(outputs[$1] || '')
         );
@@ -222,12 +222,12 @@ const utils = {
   /**
    * Provide simple "Class" extension mechanism
    */
-  protoExtend(sub) {
+  protoExtend(sub: any) {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const Super = this;
     const Constructor = Object.prototype.hasOwnProperty.call(sub, 'constructor')
       ? sub.constructor
-      : function(...args) {
+      : function(...args: any[]) {
           Super.apply(this, args);
         };
 
diff --git a/tsconfig.json b/tsconfig.json
index 199458365d..2f0736a2a1 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,6 +6,7 @@
     "module": "commonjs",
     "checkJs": false,
     "alwaysStrict": true,
+    "noImplicitAny": true,
   },
   "include": ["./src/**/*"]
 }

From 769c521fca38bcd5d253b95cb3bdbb782e1723a7 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 11:48:39 -0800
Subject: [PATCH 06/14] a lot more types

---
 .eslintrc.js               |   4 +-
 src/Error.ts               |  33 +------
 src/StripeMethod.ts        |   4 +-
 src/StripeResource.ts      | 111 +++++++++++-----------
 src/Types.d.ts             | 185 ++++++++++++++++++++++++++++++++++++-
 src/Webhooks.ts            |  21 ++---
 src/autoPagination.ts      |   7 +-
 src/makeRequest.ts         |  67 +++++++-------
 src/multipart.ts           |   4 +-
 src/net/FetchHttpClient.ts |  49 +++++-----
 src/net/HttpClient.ts      |  36 ++++----
 src/net/NodeHttpClient.ts  |  99 ++++++++++----------
 src/stripe.ts              |  80 ++++++++--------
 src/utils.ts               |  32 +++----
 14 files changed, 445 insertions(+), 287 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index 4eb5fcc6be..d10ac49cb3 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -265,11 +265,11 @@ module.exports = {
         '@typescript-eslint/no-empty-interface': 0,
         '@typescript-eslint/no-unused-vars': 0,
         '@typescript-eslint/triple-slash-reference': 0,
-        '@typescript-eslint/ban-ts-ignore': 0,
+        '@typescript-eslint/ban-ts-ignore': 'off',
         '@typescript-eslint/no-empty-function': 0,
         '@typescript-eslint/camelcase': 0,
         '@typescript-eslint/no-explicit-any': 0,
-        '@typescript-eslint/explicit-function-return-type': 0,
+        '@typescript-eslint/explicit-function-return-type': 'error',
         '@typescript-eslint/no-var-requires': 0,
         'prefer-rest-params': 'off',
       },
diff --git a/src/Error.ts b/src/Error.ts
index 3e5078236c..d4fef7bb93 100644
--- a/src/Error.ts
+++ b/src/Error.ts
@@ -1,35 +1,4 @@
 /* eslint-disable camelcase */
-type RawErrorType =
-  | 'card_error'
-  | 'invalid_request_error'
-  | 'api_error'
-  | 'idempotency_error'
-  | 'rate_limit_error'
-  | 'authentication_error'
-  | 'invalid_grant';
-
-type StripeRawError = {
-  message?: string;
-  type?: RawErrorType;
-
-  headers?: {[header: string]: string};
-  statusCode?: number;
-  requestId?: string;
-  code?: string;
-  doc_url?: string;
-  decline_code?: string;
-  param?: string;
-  detail?: string;
-  charge?: string;
-  payment_method_type?: string;
-
-  payment_intent?: any;
-  payment_method?: any;
-  setup_intent?: any;
-  source?: any;
-  exception?: any;
-};
-
 /**
  * StripeError is the base error from which all other more specific Stripe errors derive.
  * Specifically for errors returned from Stripe's REST API.
@@ -83,7 +52,7 @@ class StripeError extends Error {
   /**
    * Helper factory which takes raw stripe errors and outputs wrapping instances
    */
-  static generate(rawStripeError: StripeRawError) {
+  static generate(rawStripeError: StripeRawError): StripeError {
     switch (rawStripeError.type) {
       case 'card_error':
         return new StripeCardError(rawStripeError);
diff --git a/src/StripeMethod.ts b/src/StripeMethod.ts
index f2c0595988..51c6a716ea 100644
--- a/src/StripeMethod.ts
+++ b/src/StripeMethod.ts
@@ -19,13 +19,13 @@ const makeAutoPaginationMethods = autoPagination.makeAutoPaginationMethods;
  *  Usefully for applying transforms to data on a per-method basis.
  * @param [spec.host] Hostname for the request.
  */
-function stripeMethod(spec) {
+function stripeMethod(spec): (...args: any[]) => Promise<any> {
   if (spec.path !== undefined && spec.fullPath !== undefined) {
     throw new Error(
       `Method spec specified both a 'path' (${spec.path}) and a 'fullPath' (${spec.fullPath}).`
     );
   }
-  return function(...args) {
+  return function(...args: any[]): Promise<any> {
     const callback = typeof args[args.length - 1] == 'function' && args.pop();
 
     spec.urlParams = utils.extractUrlParams(
diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index 551da2b02d..4f8a68a996 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -12,17 +12,6 @@ const {
 
 const {HttpClient} = require('./net/HttpClient');
 
-type Settings = {
-  timeout?: number;
-  maxNetworkRetries?: number;
-};
-
-type Options = {
-  settings?: Settings;
-  streaming?: boolean;
-  headers?: Record<string, string>;
-};
-
 // Provide extension mechanism for Stripe Resource Sub-Classes
 StripeResource.extend = utils.protoExtend;
 
@@ -36,7 +25,7 @@ const MAX_RETRY_AFTER_WAIT = 60;
 /**
  * Encapsulates request logic for a Stripe Resource
  */
-function StripeResource(stripe, deprecatedUrlData?: never) {
+function StripeResource(stripe: StripeObject, deprecatedUrlData?: never): void {
   this._stripe = stripe;
   if (deprecatedUrlData) {
     throw new Error(
@@ -53,7 +42,7 @@ function StripeResource(stripe, deprecatedUrlData?: never) {
   // DEPRECATED: This was kept for backwards compatibility in case users were
   // using this, but basic methods are now explicitly defined on a resource.
   if (this.includeBasic) {
-    this.includeBasic.forEach(function(methodName) {
+    this.includeBasic.forEach(function(methodName: string) {
       this[methodName] = StripeResource.BASIC_METHODS[methodName];
     }, this);
   }
@@ -62,12 +51,13 @@ function StripeResource(stripe, deprecatedUrlData?: never) {
 }
 
 StripeResource.prototype = {
+  _stripe: null as StripeObject,
   path: '',
 
   // Methods that don't use the API's default '/v1' path can override it with this setting.
   basePath: null,
 
-  initialize() {},
+  initialize(): void {},
 
   // Function to override the default data processor. This allows full control
   // over how a StripeResource's request data will get converted into an HTTP
@@ -82,7 +72,7 @@ StripeResource.prototype = {
   createFullPath(
     commandPath: string | ((urlData: Record<string, unknown>) => string),
     urlData: Record<string, unknown>
-  ) {
+  ): string {
     const urlParts = [this.basePath(urlData), this.path(urlData)];
 
     if (typeof commandPath === 'function') {
@@ -103,7 +93,7 @@ StripeResource.prototype = {
   // Creates a relative resource path with symbols left in (unlike
   // createFullPath which takes some data to replace them with). For example it
   // might produce: /invoices/{id}
-  createResourcePathWithSymbols(pathWithSymbols: string) {
+  createResourcePathWithSymbols(pathWithSymbols: string): string {
     // If there is no path beyond the resource path, we want to produce just
     // /<resource path> rather than /<resource path>/.
     if (pathWithSymbols) {
@@ -113,7 +103,7 @@ StripeResource.prototype = {
     }
   },
 
-  _joinUrlParts(parts: Array<string>) {
+  _joinUrlParts(parts: Array<string>): string {
     // Replace any accidentally doubled up slashes. This previously used
     // path.join, which would do this as well. Unfortunately we need to do this
     // as the functions for creating paths are technically part of the public
@@ -124,8 +114,8 @@ StripeResource.prototype = {
   // DEPRECATED: Here for backcompat in case users relied on this.
   wrapTimeout: utils.callbackifyPromiseWithTimeout,
 
-  _timeoutHandler(timeout, req, callback) {
-    return () => {
+  _timeoutHandler(timeout: number, req, callback): () => void {
+    return (): void => {
       const timeoutErr = new TypeError('ETIMEDOUT');
       (timeoutErr as any).code = 'ETIMEDOUT';
 
@@ -135,8 +125,8 @@ StripeResource.prototype = {
 
   _addHeadersDirectlyToObject(
     obj: Record<string, unknown>,
-    headers: Record<string, unknown>
-  ) {
+    headers: RequestHeaders
+  ): void {
     // For convenience, make some headers easily accessible on
     // lastResponse.
 
@@ -148,10 +138,10 @@ StripeResource.prototype = {
   },
 
   _makeResponseEvent(
-    requestEvent,
+    requestEvent: RequestEvent,
     statusCode: number,
-    headers: Record<string, unknown>
-  ) {
+    headers: RequestHeaders
+  ): ResponseEvent {
     const requestEndTime = Date.now();
     const requestDurationMs = requestEndTime - requestEvent.request_start_time;
 
@@ -169,7 +159,7 @@ StripeResource.prototype = {
     });
   },
 
-  _getRequestId(headers: Record<string, unknown>) {
+  _getRequestId(headers: RequestHeaders): HttpHeaderValue {
     return headers['request-id'];
   },
 
@@ -183,8 +173,11 @@ StripeResource.prototype = {
    * still be buffered/parsed and handled by _jsonResponseHandler -- see
    * makeRequest)
    */
-  _streamingResponseHandler(requestEvent, callback) {
-    return (res) => {
+  _streamingResponseHandler(
+    requestEvent: RequestEvent,
+    callback: RequestCallback
+  ) {
+    return (res: HttpClientResponseInterface) => {
       const headers = res.getHeaders();
 
       const streamCompleteCallback = () => {
@@ -216,8 +209,8 @@ StripeResource.prototype = {
    * parses the JSON and returns it (i.e. passes it to the callback) if there
    * is no "error" field. Otherwise constructs/passes an appropriate Error.
    */
-  _jsonResponseHandler(requestEvent, callback) {
-    return (res) => {
+  _jsonResponseHandler(requestEvent: RequestEvent, callback: RequestCallback) {
+    return (res: HttpClientResponseInterface): void => {
       const headers = res.getHeaders();
       const requestId = this._getRequestId(headers);
       const statusCode = res.getStatusCode();
@@ -264,7 +257,7 @@ StripeResource.prototype = {
 
             return jsonResponse;
           },
-          (e) => {
+          (e: Error) => {
             throw new StripeAPIError({
               message: 'Invalid JSON received from the Stripe API',
               exception: e,
@@ -292,14 +285,18 @@ StripeResource.prototype = {
     };
   },
 
-  _generateConnectionErrorMessage(requestRetries) {
+  _generateConnectionErrorMessage(requestRetries: number): string {
     return `An error occurred with our connection to Stripe.${
       requestRetries > 0 ? ` Request was retried ${requestRetries} times.` : ''
     }`;
   },
 
-  _errorHandler(req, requestRetries, callback) {
-    return (message, detail) => {
+  _errorHandler(
+    res: never,
+    requestRetries: number,
+    callback: RequestCallback
+  ): (message: string, detail: string) => void {
+    return (message: string, detail: string): void => {
       callback.call(
         this,
         new StripeConnectionError({
@@ -312,7 +309,12 @@ StripeResource.prototype = {
   },
 
   // For more on when and how to retry API requests, see https://stripe.com/docs/error-handling#safely-retrying-requests-with-idempotency
-  _shouldRetry(res, numRetries: number, maxRetries: number, error?) {
+  _shouldRetry(
+    res: HttpClientResponseInterface,
+    numRetries: number,
+    maxRetries: number,
+    error?
+  ): boolean {
     if (
       error &&
       numRetries === 0 &&
@@ -357,7 +359,10 @@ StripeResource.prototype = {
     return false;
   },
 
-  _getSleepTimeInMS(numRetries: number, retryAfter: number | null = null) {
+  _getSleepTimeInMS(
+    numRetries: number,
+    retryAfter: number | null = null
+  ): number {
     const initialNetworkRetryDelay = this._stripe.getInitialNetworkRetryDelay();
     const maxNetworkRetryDelay = this._stripe.getMaxNetworkRetryDelay();
 
@@ -385,14 +390,14 @@ StripeResource.prototype = {
   },
 
   // Max retries can be set on a per request basis. Favor those over the global setting
-  _getMaxNetworkRetries(settings: Settings = {}) {
+  _getMaxNetworkRetries(settings: RequestSettings = {}): number {
     return settings.maxNetworkRetries &&
       Number.isInteger(settings.maxNetworkRetries)
       ? settings.maxNetworkRetries
       : this._stripe.getMaxNetworkRetries();
   },
 
-  _defaultIdempotencyKey(method: string, settings: Settings) {
+  _defaultIdempotencyKey(method: string, settings: RequestSettings): string {
     // If this is a POST and we allow multiple retries, ensure an idempotency key.
     const maxRetries = this._getMaxNetworkRetries(settings);
 
@@ -408,8 +413,8 @@ StripeResource.prototype = {
     apiVersion: string,
     clientUserAgent: string,
     method: string,
-    userSuppliedHeaders: Record<string, unknown>,
-    userSuppliedSettings: Settings
+    userSuppliedHeaders: RequestHeaders,
+    userSuppliedSettings: RequestSettings
   ): Record<string, unknown> {
     const defaultHeaders = {
       // Use specified auth token or use default from this stripe instance:
@@ -425,7 +430,7 @@ StripeResource.prototype = {
         method,
         userSuppliedSettings
       ),
-    };
+    } as RequestHeaders;
 
     // As per https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.2:
     //   A user agent SHOULD send a Content-Length in a request message when
@@ -483,7 +488,7 @@ StripeResource.prototype = {
     }
   },
 
-  _recordRequestMetrics(requestId, requestDurationMs): void {
+  _recordRequestMetrics(requestId: string, requestDurationMs: number): void {
     if (this._stripe.getTelemetryEnabled() && requestId) {
       if (
         this._stripe._prevRequestMetrics.length >
@@ -505,20 +510,20 @@ StripeResource.prototype = {
     method: string,
     host: string,
     path: string,
-    data: unknown,
+    data: string,
     auth: string,
-    options: Options = {},
-    callback
+    options: RequestOptions = {},
+    callback: RequestCallback
   ) {
-    let requestData;
+    let requestData: string;
 
     const retryRequest = (
       requestFn: typeof makeRequest,
       apiVersion: string,
-      headers: Record<string, unknown>,
+      headers: RequestHeaders,
       requestRetries: number,
       retryAfter: number | null
-    ) => {
+    ): NodeJS.Timeout => {
       return setTimeout(
         requestFn,
         this._getSleepTimeInMS(requestRetries, retryAfter),
@@ -530,9 +535,9 @@ StripeResource.prototype = {
 
     const makeRequest = (
       apiVersion: string,
-      headers: Record<string, unknown>,
+      headers: RequestHeaders,
       numRetries: number
-    ) => {
+    ): void => {
       // timeout can be set on a per-request basis. Favor that over the global setting
       const timeout =
         options.settings &&
@@ -557,7 +562,7 @@ StripeResource.prototype = {
 
       const requestStartTime = Date.now();
 
-      const requestEvent = utils.removeNullish({
+      const requestEvent: RequestEvent = utils.removeNullish({
         api_version: apiVersion,
         account: headers['Stripe-Account'],
         idempotency_key: headers['Idempotency-Key'],
@@ -573,7 +578,7 @@ StripeResource.prototype = {
       this._stripe._emitter.emit('request', requestEvent);
 
       req
-        .then((res) => {
+        .then((res: HttpClientResponseInterface) => {
           if (this._shouldRetry(res, requestRetries, maxRetries)) {
             return retryRequest(
               makeRequest,
@@ -614,14 +619,14 @@ StripeResource.prototype = {
         });
     };
 
-    const prepareAndMakeRequest = (error, data) => {
+    const prepareAndMakeRequest = (error: Error, data: string): void => {
       if (error) {
         return callback(error);
       }
 
       requestData = data;
 
-      this._stripe.getClientUserAgent((clientUserAgent) => {
+      this._stripe.getClientUserAgent((clientUserAgent: string) => {
         const apiVersion = this._stripe.getApiField('version');
         const headers = this._makeHeaders(
           auth,
diff --git a/src/Types.d.ts b/src/Types.d.ts
index beac628435..5556ac59de 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -1,4 +1,185 @@
-type StripeResourceObject = {};
+/* eslint-disable camelcase */
+type StripeObject = {
+  on: any;
+  off: any;
+  once: any;
+  VERSION: string;
+  StripeResource: StripeResourceObject;
+  errors: any;
+  webhooks: any;
+  getApiField: <T = string>(name: string) => T;
+  _prepResources: () => void;
+  _setAppInfo: (appInfo: AppInfo) => void;
+  _setApiKey: (apiKey: string) => void;
+  _prevRequestMetrics: number[];
+  _api: {
+    auth: string;
+    host: string;
+    port: string | number;
+    protocol: string;
+    basePath: string;
+    version: string;
+    timeout: string;
+    maxNetworkRetries: number;
+    agent: string;
+    httpClient: any;
+    dev: boolean;
+    stripeAccount: string;
+  };
+  _emitter: import('events').EventEmitter;
+  _enableTelemetry: boolean;
+  _getPropsFromConfig: (config: Record<string, unknown>) => UserProvidedConfig;
+};
+type StripeResourceObject = {
+  createResourcePathWithSymbols: (path: string) => string;
+  createFullPath: (
+    interpolator: UrlInterpolator,
+    urlData: RequestData
+  ) => string;
+  _request: (
+    method: string,
+    host: string,
+    path: string,
+    data: RequestData,
+    auth: string,
+    options: RequestOptions,
+    callback: RequestCallback
+  ) => Promise<any>;
+};
+type RequestCallback = (
+  this: StripeResourceObject | void,
+  error: Error,
+  response?: any
+) => void;
 
-type HttpHeaders = Record<string, string | number | string[]>;
+type RequestEvent = {
+  api_version?: string;
+  account?: string;
+  idempotency_key?: string;
+  method?: string;
+  path?: string;
+  request_start_time?: number;
+};
+
+type ResponseEvent = {
+  api_version?: string;
+  account?: string;
+  idempotency_key?: string;
+  method?: string;
+  path?: string;
+  status?: number;
+  request_id?: string;
+  elapsed?: number;
+  request_start_time?: number;
+  request_end_time?: number;
+};
+type RequestOptions = {
+  settings?: RequestSettings;
+  streaming?: boolean;
+  headers?: RequestHeaders;
+};
+type RequestSettings = {
+  timeout?: number;
+  maxNetworkRetries?: number;
+};
+type UserProvidedConfig = {
+  apiVersion?: string;
+  protocol?: string;
+  host?: string;
+  httpAgent?: any;
+  timeout?: number;
+  port?: number;
+  maxNetworkRetries?: number;
+  httpClient?: HttpClientInterface;
+  stripeAccount?: string;
+  typescript?: boolean;
+  telemetry?: boolean;
+  appInfo?: AppInfo;
+};
+type HttpHeaderValue = string | number | string[];
+type RequestHeaders = Record<string, string | number | string[]>;
 type RequestData = Record<string, unknown>;
+type RequestArgs = Array<any>;
+type UrlInterpolator = (params: Record<string, unknown>) => string;
+type AppInfo = {
+  name?: string;
+} & Record<string, unknown>;
+
+type MethodSpec = {
+  method: string;
+  urlParams: Array<string>;
+  path?: string;
+  fullPath?: string;
+  encode: (data: RequestData) => RequestData;
+  validator: (data: RequestData, headers: RequestHeaders) => void;
+  headers: Record<string, string>;
+  streaming?: boolean;
+  host?: string;
+  transformResponseData?: (response: HttpClientResponseInterface) => any;
+};
+type RequestOpts = {
+  requestMethod: string;
+  requestPath: string;
+  bodyData: RequestData;
+  queryData: RequestData;
+  auth: string;
+  headers: RequestHeaders;
+  host: string;
+  streaming: boolean;
+  settings: RequestSettings;
+};
+type StripeCryptoProvider = {
+  computeHMACSignature: (data: string, secret: string) => string;
+  computeHMACSignatureAsync: (data: string, secret: string) => Promise<string>;
+};
+interface HttpClientInterface {
+  getClientName: () => string;
+  makeRequest: (
+    host: string,
+    port: string,
+    path: string,
+    method: string,
+    headers: RequestHeaders,
+    requestData: RequestData,
+    protocol: string,
+    timeout: number
+  ) => Promise<HttpClientResponseInterface>;
+}
+type ResponseHeaders = Record<string, string>;
+interface HttpClientResponseInterface {
+  getStatusCode: () => number;
+  getHeaders: () => ResponseHeaders;
+  getRawResponse: () => unknown;
+  toStream: (streamCompleteCallback: () => void) => unknown;
+  toJSON: () => Promise<any>;
+}
+type RawErrorType =
+  | 'card_error'
+  | 'invalid_request_error'
+  | 'api_error'
+  | 'idempotency_error'
+  | 'rate_limit_error'
+  | 'authentication_error'
+  | 'invalid_grant';
+
+type StripeRawError = {
+  message?: string;
+  type?: RawErrorType;
+
+  headers?: {[header: string]: string};
+  statusCode?: number;
+  requestId?: string;
+  code?: string;
+  doc_url?: string;
+  decline_code?: string;
+  param?: string;
+  detail?: string;
+  charge?: string;
+  payment_method_type?: string;
+
+  payment_intent?: any;
+  payment_method?: any;
+  setup_intent?: any;
+  source?: any;
+  exception?: any;
+};
diff --git a/src/Webhooks.ts b/src/Webhooks.ts
index 1381f03c23..68c698d747 100644
--- a/src/Webhooks.ts
+++ b/src/Webhooks.ts
@@ -2,11 +2,6 @@ import utils = require('./utils');
 import _Error = require('./Error');
 const {StripeError, StripeSignatureVerificationError} = _Error;
 
-type StripeCryptoProvider = {
-  computeHMACSignature: (data: string, secret: string) => string;
-  computeHMACSignatureAsync: (data: string, secret: string) => Promise<string>;
-};
-
 type WebhookPayload = string | Buffer;
 type WebhookHeader = string | Buffer;
 type WebhookParsedHeader = {
@@ -26,6 +21,8 @@ type WebhookTestHeaderOptions = {
   signature: string;
   cryptoProvider: StripeCryptoProvider;
 };
+type WebhookEvent = Record<string, unknown>;
+
 const Webhook = {
   DEFAULT_TOLERANCE: 300, // 5 minutes
   signature: null as typeof signature,
@@ -36,7 +33,7 @@ const Webhook = {
     secret: string,
     tolerance: null,
     cryptoProvider: StripeCryptoProvider
-  ) {
+  ): WebhookEvent {
     this.signature.verifyHeader(
       payload,
       header,
@@ -56,7 +53,7 @@ const Webhook = {
     secret: string,
     tolerance: number,
     cryptoProvider: StripeCryptoProvider
-  ) {
+  ): Promise<WebhookEvent> {
     await this.signature.verifyHeaderAsync(
       payload,
       header,
@@ -81,7 +78,7 @@ const Webhook = {
    * @property {string} signature - Computed webhook signature
    * @property {CryptoProvider} cryptoProvider - Crypto provider to use for computing the signature if none was provided. Defaults to NodeCryptoProvider.
    */
-  generateTestHeaderString: function(opts: WebhookTestHeaderOptions) {
+  generateTestHeaderString: function(opts: WebhookTestHeaderOptions): string {
     if (!opts) {
       throw new StripeError({
         message: 'Options are required',
@@ -119,7 +116,7 @@ const signature = {
     secret: string,
     tolerance: number,
     cryptoProvider: StripeCryptoProvider
-  ) {
+  ): boolean {
     const {
       decodedHeader: header,
       decodedPayload: payload,
@@ -149,7 +146,7 @@ const signature = {
     secret: string,
     tolerance: number,
     cryptoProvider: StripeCryptoProvider
-  ) {
+  ): Promise<boolean> {
     const {
       decodedHeader: header,
       decodedPayload: payload,
@@ -176,7 +173,7 @@ const signature = {
 function makeHMACContent(
   payload: WebhookPayload,
   details: WebhookParsedHeader
-) {
+): string {
   return `${details.timestamp}.${payload}`;
 }
 
@@ -240,7 +237,7 @@ function validateComputedSignature(
   details: WebhookParsedHeader,
   expectedSignature: string,
   tolerance: number
-) {
+): boolean {
   const signatureFound = !!details.signatures.filter(
     utils.secureCompare.bind(utils, expectedSignature)
   ).length;
diff --git a/src/autoPagination.ts b/src/autoPagination.ts
index b98f44d122..0032ad77b9 100644
--- a/src/autoPagination.ts
+++ b/src/autoPagination.ts
@@ -1,7 +1,12 @@
 import makeRequest = require('./makeRequest');
 const utils = require('./utils');
 
-function makeAutoPaginationMethods(self, requestArgs, spec, firstPagePromise) {
+function makeAutoPaginationMethods(
+  self: StripeResourceObject,
+  requestArgs,
+  spec,
+  firstPagePromise
+) {
   const promiseCache = {currentPromise: null};
   const reverseIteration = isReverseIteration(requestArgs);
   let pagePromise = firstPagePromise;
diff --git a/src/makeRequest.ts b/src/makeRequest.ts
index 515f253e77..42dc109bfb 100644
--- a/src/makeRequest.ts
+++ b/src/makeRequest.ts
@@ -1,28 +1,18 @@
 const utils = require('./utils');
 
-type MethodSpec = {
-  method: string;
-  urlParams: Array<string>;
-  path?: string;
-  fullPath?: string;
-  encode: (data: Record<string, unknown>) => Record<string, unknown>;
-  validator: (
-    data: Record<string, unknown>,
-    headers: Record<string, string>
-  ) => void;
-  headers: Record<string, string>;
-  streaming?: boolean;
-  host?: string;
-};
-
-function getRequestOpts(self, requestArgs, spec: MethodSpec, overrideData) {
+function getRequestOpts(
+  self: StripeResourceObject,
+  requestArgs: RequestArgs,
+  spec: MethodSpec,
+  overrideData: RequestData
+): RequestOpts {
   // Extract spec values with defaults.
   const requestMethod = (spec.method || 'GET').toUpperCase();
   const urlParams = spec.urlParams || [];
-  const encode = spec.encode || ((data) => data);
+  const encode = spec.encode || ((data): RequestData => data);
 
   const isUsingFullPath = !!spec.fullPath;
-  const commandPath = utils.makeURLInterpolator(
+  const commandPath: UrlInterpolator = utils.makeURLInterpolator(
     isUsingFullPath ? spec.fullPath : spec.path || ''
   );
   // When using fullPath, we ignore the resource path as it should already be
@@ -32,23 +22,20 @@ function getRequestOpts(self, requestArgs, spec: MethodSpec, overrideData) {
     : self.createResourcePathWithSymbols(spec.path);
 
   // Don't mutate args externally.
-  const args = [].slice.call(requestArgs);
+  const args: RequestArgs = [].slice.call(requestArgs);
 
   // Generate and validate url params.
-  const urlData = urlParams.reduce<Record<string, unknown>>(
-    (urlData, param) => {
-      const arg = args.shift();
-      if (typeof arg !== 'string') {
-        throw new Error(
-          `Stripe: Argument "${param}" must be a string, but got: ${arg} (on API request to \`${requestMethod} ${path}\`)`
-        );
-      }
+  const urlData = urlParams.reduce<RequestData>((urlData, param) => {
+    const arg = args.shift();
+    if (typeof arg !== 'string') {
+      throw new Error(
+        `Stripe: Argument "${param}" must be a string, but got: ${arg} (on API request to \`${requestMethod} ${path}\`)`
+      );
+    }
 
-      urlData[param] = arg;
-      return urlData;
-    },
-    {}
-  );
+    urlData[param] = arg;
+    return urlData;
+  }, {});
 
   // Pull request data and options (headers, auth) from args.
   const dataFromArgs = utils.getDataFromArgs(args);
@@ -92,9 +79,14 @@ function getRequestOpts(self, requestArgs, spec: MethodSpec, overrideData) {
   };
 }
 
-function makeRequest(self, requestArgs, spec, overrideData) {
-  return new Promise((resolve, reject) => {
-    let opts;
+function makeRequest(
+  self: StripeResourceObject,
+  requestArgs: RequestArgs,
+  spec: MethodSpec,
+  overrideData: RequestData
+): Promise<any> {
+  return new Promise<any>((resolve, reject) => {
+    let opts: RequestOpts;
     try {
       opts = getRequestOpts(self, requestArgs, spec, overrideData);
     } catch (err) {
@@ -102,7 +94,10 @@ function makeRequest(self, requestArgs, spec, overrideData) {
       return;
     }
 
-    function requestCallback(err: any, response) {
+    function requestCallback(
+      err: any,
+      response: HttpClientResponseInterface
+    ): void {
       if (err) {
         reject(err);
       } else {
diff --git a/src/multipart.ts b/src/multipart.ts
index cff39bbd99..3aa6a7f91b 100644
--- a/src/multipart.ts
+++ b/src/multipart.ts
@@ -62,7 +62,7 @@ const multipartDataGenerator = (method, data, headers) => {
 const streamProcessor = (
   method: string,
   data: RequestData,
-  headers: HttpHeaders,
+  headers: RequestHeaders,
   callback
 ) => {
   const bufferArray = [];
@@ -91,7 +91,7 @@ const streamProcessor = (
 const multipartRequestDataProcessor = (
   method: string,
   data: RequestData,
-  headers: HttpHeaders,
+  headers: RequestHeaders,
   callback
 ) => {
   data = data || {};
diff --git a/src/net/FetchHttpClient.ts b/src/net/FetchHttpClient.ts
index 630bddc42d..6a3f845986 100644
--- a/src/net/FetchHttpClient.ts
+++ b/src/net/FetchHttpClient.ts
@@ -9,33 +9,30 @@ const {HttpClient, HttpClientResponse} = _HttpClient;
  * Fetch API. As an example, this could be the function provided by the
  * node-fetch package (https://github.com/node-fetch/node-fetch).
  */
-class FetchHttpClient extends HttpClient {
-  _fetchFn: (
-    input: RequestInfo | URL,
-    init?: RequestInit | undefined
-  ) => Promise<Response>;
+class FetchHttpClient extends HttpClient implements HttpClientInterface {
+  _fetchFn: typeof fetch;
   _res: Response;
 
-  constructor(fetchFn) {
+  constructor(fetchFn: typeof fetch) {
     super();
     this._fetchFn = fetchFn;
   }
 
   /** @override. */
-  getClientName() {
+  getClientName(): string {
     return 'fetch';
   }
 
   makeRequest(
-    host,
-    port,
-    path,
-    method,
-    headers,
-    requestData,
-    protocol,
-    timeout
-  ) {
+    host: string,
+    port: string,
+    path: string,
+    method: string,
+    headers: RequestHeaders,
+    requestData: RequestData,
+    protocol: string,
+    timeout: number
+  ): Promise<HttpClientResponseInterface> {
     const isInsecureConnection = protocol === 'http';
 
     const url = new URL(
@@ -72,7 +69,7 @@ class FetchHttpClient extends HttpClient {
     // to be established followed by 20s for the body, Fetch would timeout but
     // Node would not. The more fine-grained timeout cannot be implemented with
     // fetch.
-    let pendingTimeoutId;
+    let pendingTimeoutId: NodeJS.Timeout;
     const timeoutPromise = new Promise((_, reject) => {
       pendingTimeoutId = setTimeout(() => {
         pendingTimeoutId = null;
@@ -81,7 +78,7 @@ class FetchHttpClient extends HttpClient {
     });
 
     return Promise.race([fetchPromise, timeoutPromise])
-      .then((res) => {
+      .then((res: Response) => {
         return new FetchHttpClientResponse(res);
       })
       .finally(() => {
@@ -92,10 +89,11 @@ class FetchHttpClient extends HttpClient {
   }
 }
 
-class FetchHttpClientResponse extends HttpClientResponse {
+class FetchHttpClientResponse extends HttpClientResponse
+  implements HttpClientResponseInterface {
   _res: Response;
 
-  constructor(res) {
+  constructor(res: Response) {
     super(
       res.status,
       FetchHttpClientResponse._transformHeadersToObject(res.headers)
@@ -103,11 +101,11 @@ class FetchHttpClientResponse extends HttpClientResponse {
     this._res = res;
   }
 
-  getRawResponse() {
+  getRawResponse(): Response {
     return this._res;
   }
 
-  toStream(streamCompleteCallback) {
+  toStream(streamCompleteCallback: () => void): ReadableStream<Uint8Array> {
     // Unfortunately `fetch` does not have event handlers for when the stream is
     // completely read. We therefore invoke the streamCompleteCallback right
     // away. This callback emits a response event with metadata and completes
@@ -119,15 +117,14 @@ class FetchHttpClientResponse extends HttpClientResponse {
     return this._res.body;
   }
 
-  toJSON() {
+  toJSON(): Promise<any> {
     return this._res.json();
   }
 
-  static _transformHeadersToObject(headers) {
+  static _transformHeadersToObject(headers: Headers): ResponseHeaders {
     // Fetch uses a Headers instance so this must be converted to a barebones
     // JS object to meet the HttpClient interface.
-    const headersObj = {};
-
+    const headersObj: ResponseHeaders = {};
     for (const entry of headers) {
       if (!Array.isArray(entry) || entry.length != 2) {
         throw new Error(
diff --git a/src/net/HttpClient.ts b/src/net/HttpClient.ts
index 2c035d7cd7..56c67090d4 100644
--- a/src/net/HttpClient.ts
+++ b/src/net/HttpClient.ts
@@ -9,30 +9,30 @@ type TimeoutError = TypeError & {code?: string};
  * 2. A client class which extends HttpClient and implements all methods,
  *    returning their own response class when making requests.
  */
-class HttpClient {
+class HttpClient implements HttpClientInterface {
   static CONNECTION_CLOSED_ERROR_CODES: string[];
   static TIMEOUT_ERROR_CODE: string;
 
   /** The client name used for diagnostics. */
-  getClientName() {
+  getClientName(): string {
     throw new Error('getClientName not implemented.');
   }
 
   makeRequest(
-    host,
-    port,
-    path,
-    method,
-    headers,
-    requestData,
-    protocol,
-    timeout
-  ) {
+    host: string,
+    port: string,
+    path: string,
+    method: string,
+    headers: RequestHeaders,
+    requestData: RequestData,
+    protocol: string,
+    timeout: number
+  ): Promise<HttpClientResponseInterface> {
     throw new Error('makeRequest not implemented.');
   }
 
   /** Helper to make a consistent timeout error across implementations. */
-  static makeTimeoutError() {
+  static makeTimeoutError(): TimeoutError {
     const timeoutErr: TimeoutError = new TypeError(
       HttpClient.TIMEOUT_ERROR_CODE
     );
@@ -44,11 +44,11 @@ class HttpClient {
 HttpClient.CONNECTION_CLOSED_ERROR_CODES = ['ECONNRESET', 'EPIPE'];
 HttpClient.TIMEOUT_ERROR_CODE = 'ETIMEDOUT';
 
-class HttpClientResponse {
+class HttpClientResponse implements HttpClientResponseInterface {
   _statusCode: number;
-  _headers: Record<string, string>;
+  _headers: ResponseHeaders;
 
-  constructor(statusCode, headers) {
+  constructor(statusCode: number, headers: ResponseHeaders) {
     this._statusCode = statusCode;
     this._headers = headers;
   }
@@ -57,15 +57,15 @@ class HttpClientResponse {
     return this._statusCode;
   }
 
-  getHeaders(): Record<string, string> {
+  getHeaders(): ResponseHeaders {
     return this._headers;
   }
 
-  getRawResponse() {
+  getRawResponse(): unknown {
     throw new Error('getRawResponse not implemented.');
   }
 
-  toStream(streamCompleteCallback) {
+  toStream(streamCompleteCallback: () => void): unknown {
     throw new Error('toStream not implemented.');
   }
 
diff --git a/src/net/NodeHttpClient.ts b/src/net/NodeHttpClient.ts
index eff3e7fb9d..d337b677d1 100644
--- a/src/net/NodeHttpClient.ts
+++ b/src/net/NodeHttpClient.ts
@@ -14,13 +14,13 @@ const defaultHttpsAgent = new https.Agent({keepAlive: true});
 class NodeHttpClient extends HttpClient {
   _agent: http.Agent | https.Agent;
 
-  constructor(agent) {
+  constructor(agent: http.Agent | https.Agent) {
     super();
     this._agent = agent;
   }
 
   /** @override. */
-  getClientName() {
+  getClientName(): string {
     return 'node';
   }
 
@@ -29,11 +29,11 @@ class NodeHttpClient extends HttpClient {
     port: string,
     path: string,
     method: string,
-    headers: HttpHeaders,
-    requestData: Record<string, unknown>,
+    headers: RequestHeaders,
+    requestData: RequestData,
     protocol: string,
     timeout: number
-  ) {
+  ): Promise<HttpClientResponseInterface> {
     const isInsecureConnection = protocol === 'http';
 
     let agent = this._agent;
@@ -41,52 +41,55 @@ class NodeHttpClient extends HttpClient {
       agent = isInsecureConnection ? defaultHttpAgent : defaultHttpsAgent;
     }
 
-    const requestPromise = new Promise((resolve, reject) => {
-      const req = (isInsecureConnection ? http : https).request({
-        host: host,
-        port: port,
-        path,
-        method,
-        agent,
-        headers,
-        ciphers: 'DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:!MD5',
-      });
-
-      req.setTimeout(timeout, () => {
-        req.destroy(HttpClient.makeTimeoutError());
-      });
-
-      req.on('response', (res) => {
-        resolve(new NodeHttpClientResponse(res));
-      });
-
-      req.on('error', (error) => {
-        reject(error);
-      });
-
-      req.once('socket', (socket) => {
-        if (socket.connecting) {
-          socket.once(
-            isInsecureConnection ? 'connect' : 'secureConnect',
-            () => {
-              // Send payload; we're safe:
-              req.write(requestData);
-              req.end();
-            }
-          );
-        } else {
-          // we're already connected
-          req.write(requestData);
-          req.end();
-        }
-      });
-    });
+    const requestPromise = new Promise<HttpClientResponseInterface>(
+      (resolve, reject) => {
+        const req = (isInsecureConnection ? http : https).request({
+          host: host,
+          port: port,
+          path,
+          method,
+          agent,
+          headers,
+          ciphers: 'DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:!MD5',
+        });
+
+        req.setTimeout(timeout, () => {
+          req.destroy(HttpClient.makeTimeoutError());
+        });
+
+        req.on('response', (res) => {
+          resolve(new NodeHttpClientResponse(res));
+        });
+
+        req.on('error', (error) => {
+          reject(error);
+        });
+
+        req.once('socket', (socket) => {
+          if (socket.connecting) {
+            socket.once(
+              isInsecureConnection ? 'connect' : 'secureConnect',
+              () => {
+                // Send payload; we're safe:
+                req.write(requestData);
+                req.end();
+              }
+            );
+          } else {
+            // we're already connected
+            req.write(requestData);
+            req.end();
+          }
+        });
+      }
+    );
 
     return requestPromise;
   }
 }
 
-class NodeHttpClientResponse extends HttpClientResponse {
+class NodeHttpClientResponse extends HttpClientResponse
+  implements HttpClientResponseInterface {
   _res: http.IncomingMessage;
 
   constructor(res: http.IncomingMessage) {
@@ -94,11 +97,11 @@ class NodeHttpClientResponse extends HttpClientResponse {
     this._res = res;
   }
 
-  getRawResponse() {
+  getRawResponse(): http.IncomingMessage {
     return this._res;
   }
 
-  toStream(streamCompleteCallback) {
+  toStream(streamCompleteCallback: () => void): http.IncomingMessage {
     // The raw response is itself the stream, so we just return that. To be
     // backwards compatible, we should invoke the streamCompleteCallback only
     // once the stream has been fully consumed.
diff --git a/src/stripe.ts b/src/stripe.ts
index c9f8784f25..f40acf52df 100644
--- a/src/stripe.ts
+++ b/src/stripe.ts
@@ -5,7 +5,7 @@ const resources = require('./resources');
 const DEFAULT_HOST = 'api.stripe.com';
 const DEFAULT_PORT = '443';
 const DEFAULT_BASE_PATH = '/v1/';
-const DEFAULT_API_VERSION = null;
+const DEFAULT_API_VERSION = null as string;
 
 const DEFAULT_TIMEOUT = 80000;
 
@@ -24,7 +24,7 @@ Stripe.USER_AGENT = {
 };
 
 /** @private */
-Stripe._UNAME_CACHE = null;
+Stripe._UNAME_CACHE = null as Promise<string>;
 
 const MAX_NETWORK_RETRY_DELAY_SEC = 2;
 const INITIAL_NETWORK_RETRY_DELAY_SEC = 0.5;
@@ -47,6 +47,7 @@ const ALLOWED_CONFIG_PROPERTIES = [
 
 const EventEmitter = require('events').EventEmitter;
 import StripeResource = require('./StripeResource');
+import * as http from 'http';
 Stripe.StripeResource = StripeResource;
 Stripe.resources = resources;
 
@@ -57,7 +58,7 @@ Stripe.HttpClientResponse = HttpClientResponse;
 const CryptoProvider = require('./crypto/CryptoProvider');
 Stripe.CryptoProvider = CryptoProvider;
 
-function Stripe(key, config = {}) {
+function Stripe(this: StripeObject, key: string, config = {}): void {
   if (!(this instanceof Stripe)) {
     return new (Stripe as any)(key, config);
   }
@@ -137,7 +138,7 @@ function Stripe(key, config = {}) {
 Stripe.errors = _Error;
 Stripe.webhooks = require('./Webhooks');
 
-Stripe.createNodeHttpClient = (agent) => {
+Stripe.createNodeHttpClient = (agent: http.Agent): typeof HttpClient => {
   const {NodeHttpClient} = require('./net/NodeHttpClient');
   return new NodeHttpClient(agent);
 };
@@ -149,7 +150,7 @@ Stripe.createNodeHttpClient = (agent) => {
  * A fetch function can optionally be passed in as a parameter. If none is
  * passed, will default to the default `fetch` function in the global scope.
  */
-Stripe.createFetchHttpClient = (fetchFn) => {
+Stripe.createFetchHttpClient = (fetchFn: typeof fetch): typeof HttpClient => {
   const {FetchHttpClient} = require('./net/FetchHttpClient');
   return new FetchHttpClient(fetchFn);
 };
@@ -158,7 +159,7 @@ Stripe.createFetchHttpClient = (fetchFn) => {
  * Create a CryptoProvider which uses the built-in Node crypto libraries for
  * its crypto operations.
  */
-Stripe.createNodeCryptoProvider = () => {
+Stripe.createNodeCryptoProvider = (): StripeCryptoProvider => {
   const NodeCryptoProvider = require('./crypto/NodeCryptoProvider');
   return new NodeCryptoProvider();
 };
@@ -171,7 +172,9 @@ Stripe.createNodeCryptoProvider = () => {
  * is passed, will default to the default `crypto.subtle` object in the global
  * scope.
  */
-Stripe.createSubtleCryptoProvider = (subtleCrypto) => {
+Stripe.createSubtleCryptoProvider = (
+  subtleCrypto: typeof crypto.subtle
+): StripeCryptoProvider => {
   const SubtleCryptoProvider = require('./crypto/SubtleCryptoProvider');
   return new SubtleCryptoProvider(subtleCrypto);
 };
@@ -187,7 +190,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setHost(host, port, protocol) {
+  setHost(host: string, port: number, protocol: string): void {
     emitWarning(
       '`setHost` is deprecated. Use the `host` config option instead.'
     );
@@ -208,7 +211,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setProtocol(protocol) {
+  setProtocol(protocol: string): void {
     emitWarning(
       '`setProtocol` is deprecated. Use the `protocol` config option instead.'
     );
@@ -223,7 +226,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setPort(port) {
+  setPort(port: number): void {
     emitWarning(
       '`setPort` is deprecated. Use the `port` config option instead.'
     );
@@ -238,7 +241,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setApiVersion(version) {
+  setApiVersion(version: string): void {
     emitWarning(
       '`setApiVersion` is deprecated. Use the `apiVersion` config or request option instead.'
     );
@@ -262,7 +265,7 @@ Stripe.prototype = {
    *
    * stripe.customers.create(params, {apiKey: 'sk_test_...'});
    */
-  setApiKey(key) {
+  setApiKey(key: string): void {
     emitWarning(
       '`setApiKey` is deprecated. Use the `apiKey` request option instead.'
     );
@@ -272,7 +275,7 @@ Stripe.prototype = {
   /**
    * @private
    */
-  _setApiKey(key) {
+  _setApiKey(key: string): void {
     if (key) {
       this._setApiField('auth', `Bearer ${key}`);
     }
@@ -285,7 +288,7 @@ Stripe.prototype = {
    *   timeout: TIMEOUT_MS,
    * });
    */
-  setTimeout(timeout) {
+  setTimeout(timeout: number): void {
     emitWarning(
       '`setTimeout` is deprecated. Use the `timeout` config or request option instead.'
     );
@@ -304,7 +307,7 @@ Stripe.prototype = {
    *   },
    * });
    */
-  setAppInfo(info) {
+  setAppInfo(info: AppInfo): void {
     emitWarning(
       '`setAppInfo` is deprecated. Use the `appInfo` config option instead.'
     );
@@ -315,7 +318,7 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _setAppInfo(info) {
+  _setAppInfo(info: AppInfo): void {
     if (info && typeof info !== 'object') {
       throw new Error('AppInfo must be an object.');
     }
@@ -349,7 +352,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setHttpAgent(agent) {
+  setHttpAgent(agent: string): void {
     emitWarning(
       '`setHttpAgent` is deprecated. Use the `httpAgent` config option instead.'
     );
@@ -360,7 +363,7 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _setApiField(key, value) {
+  _setApiField(key: string, value: unknown): void {
     this._api[key] = value;
   },
 
@@ -371,7 +374,7 @@ Stripe.prototype = {
    *
    * It may be deprecated and removed in the future.
    */
-  getApiField(key: string): unknown {
+  getApiField<T>(key: string): T {
     return this._api[key];
   },
 
@@ -390,7 +393,7 @@ Stripe.prototype = {
    *
    * It may be deprecated and removed in the future.
    */
-  getConstant: (c) => {
+  getConstant: (c: string): unknown => {
     switch (c) {
       case 'DEFAULT_HOST':
         return DEFAULT_HOST;
@@ -407,7 +410,7 @@ Stripe.prototype = {
       case 'INITIAL_NETWORK_RETRY_DELAY_SEC':
         return INITIAL_NETWORK_RETRY_DELAY_SEC;
     }
-    return Stripe[c];
+    return ((Stripe as unknown) as Record<string, unknown>)[c];
   },
 
   getMaxNetworkRetries(): number {
@@ -422,7 +425,7 @@ Stripe.prototype = {
    * });
    *
    */
-  setMaxNetworkRetries(maxNetworkRetries: number) {
+  setMaxNetworkRetries(maxNetworkRetries: number): void {
     this._setApiNumberField('maxNetworkRetries', maxNetworkRetries);
   },
 
@@ -430,32 +433,32 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _setApiNumberField(prop: string, n: number, defaultVal?: number) {
+  _setApiNumberField(prop: string, n: number, defaultVal?: number): void {
     const val = utils.validateInteger(prop, n, defaultVal);
 
     this._setApiField(prop, val);
   },
 
-  getMaxNetworkRetryDelay() {
+  getMaxNetworkRetryDelay(): number {
     return MAX_NETWORK_RETRY_DELAY_SEC;
   },
 
-  getInitialNetworkRetryDelay() {
+  getInitialNetworkRetryDelay(): number {
     return INITIAL_NETWORK_RETRY_DELAY_SEC;
   },
 
   /**
    * @private
    */
-  getUname(cb) {
+  getUname(cb: (uname: string) => void): void {
     if (!Stripe._UNAME_CACHE) {
-      Stripe._UNAME_CACHE = new Promise((resolve) => {
-        utils.safeExec('uname -a', (err, uname) => {
+      Stripe._UNAME_CACHE = new Promise<string>((resolve) => {
+        utils.safeExec('uname -a', (err: Error, uname: string) => {
           resolve(uname);
         });
       });
     }
-    Stripe._UNAME_CACHE.then((uname) => cb(uname));
+    Stripe._UNAME_CACHE.then((uname: string) => cb(uname));
   },
 
   /**
@@ -468,7 +471,7 @@ Stripe.prototype = {
    * Gets a JSON version of a User-Agent and uses a cached version for a slight
    * speed advantage.
    */
-  getClientUserAgent(cb) {
+  getClientUserAgent(cb: (userAgent: string) => void): void {
     return this.getClientUserAgentSeeded(Stripe.USER_AGENT, cb);
   },
 
@@ -482,8 +485,11 @@ Stripe.prototype = {
    * Gets a JSON version of a User-Agent by encoding a seeded object and
    * fetching a uname from the system.
    */
-  getClientUserAgentSeeded(seed, cb) {
-    this.getUname((uname) => {
+  getClientUserAgentSeeded(
+    seed: Record<string, string>,
+    cb: (userAgent: string) => void
+  ): void {
+    this.getUname((uname: string) => {
       const userAgent: Record<string, string> = {};
       for (const field in seed) {
         userAgent[field] = encodeURIComponent(seed[field]);
@@ -512,7 +518,7 @@ Stripe.prototype = {
    *
    * It may be deprecated and removed in the future.
    */
-  getAppInfoAsString() {
+  getAppInfoAsString(): string {
     if (!this._appInfo) {
       return '';
     }
@@ -538,14 +544,14 @@ Stripe.prototype = {
    * });
    *
    */
-  setTelemetryEnabled(enableTelemetry) {
+  setTelemetryEnabled(enableTelemetry: boolean): void {
     emitWarning(
       '`setTelemetryEnabled` is deprecated. Use the `telemetry` config option instead.'
     );
     this._enableTelemetry = enableTelemetry;
   },
 
-  getTelemetryEnabled() {
+  getTelemetryEnabled(): boolean {
     return this._enableTelemetry;
   },
 
@@ -553,7 +559,7 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _prepResources() {
+  _prepResources(): void {
     for (const name in resources) {
       this[utils.pascalToCamelCase(name)] = new resources[name](this);
     }
@@ -563,7 +569,7 @@ Stripe.prototype = {
    * @private
    * This may be removed in the future.
    */
-  _getPropsFromConfig(config) {
+  _getPropsFromConfig(config: Record<string, unknown>): UserProvidedConfig {
     // If config is null or undefined, just bail early with no props
     if (!config) {
       return {};
diff --git a/src/utils.ts b/src/utils.ts
index da5d652115..75dc3017c8 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -64,7 +64,7 @@ const utils = {
    * Stringifies an Object, accommodating nested objects
    * (forming the conventional key 'parent[child]=value')
    */
-  stringifyRequestData: (data: unknown): string => {
+  stringifyRequestData: (data: RequestData | string): string => {
     return (
       qs
         .stringify(data, {
@@ -84,16 +84,16 @@ const utils = {
    *   const fn = makeURLInterpolator('some/url/{param1}/{param2}');
    *   fn({ param1: 123, param2: 456 }); // => 'some/url/123/456'
    */
-  makeURLInterpolator: (() => {
+  makeURLInterpolator: ((): ((s: string) => UrlInterpolator) => {
     const rc = {
       '\n': '\\n',
       '"': '\\"',
       '\u2028': '\\u2028',
       '\u2029': '\\u2029',
     } as Record<string, string>;
-    return (str: string) => {
+    return (str: string): UrlInterpolator => {
       const cleanString = str.replace(/["\n\r\u2028\u2029]/g, ($0) => rc[$0]);
-      return (outputs: Record<string, undefined>) => {
+      return (outputs: Record<string, undefined>): string => {
         return cleanString.replace(/\{([\s\S]+?)\}/g, ($0, $1) =>
           encodeURIComponent(outputs[$1] || '')
         );
@@ -116,7 +116,7 @@ const utils = {
    * @param {object[]} args
    * @returns {object}
    */
-  getDataFromArgs(args: Array<unknown>): Record<string, unknown> {
+  getDataFromArgs(args: RequestArgs): RequestData {
     if (!Array.isArray(args) || !args[0] || typeof args[0] !== 'object') {
       return {};
     }
@@ -152,7 +152,7 @@ const utils = {
   /**
    * Return the options hash from a list of arguments
    */
-  getOptionsFromArgs: (args: Array<unknown>): Options => {
+  getOptionsFromArgs: (args: RequestArgs): Options => {
     const opts: Options = {
       auth: null,
       headers: {},
@@ -222,12 +222,12 @@ const utils = {
   /**
    * Provide simple "Class" extension mechanism
    */
-  protoExtend(sub: any) {
+  protoExtend(sub: any): (...args: any[]) => void {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const Super = this;
     const Constructor = Object.prototype.hasOwnProperty.call(sub, 'constructor')
       ? sub.constructor
-      : function(...args: any[]) {
+      : function(...args: any[]): void {
           Super.apply(this, args);
         };
 
@@ -274,12 +274,12 @@ const utils = {
   /**
    * Remove empty values from an object
    */
-  removeNullish: (obj: Record<string, unknown>): Record<string, unknown> => {
+  removeNullish: <T>(obj: Record<string, T>): Record<string, T> => {
     if (typeof obj !== 'object') {
       throw new Error('Argument must be an object');
     }
 
-    return Object.keys(obj).reduce((result, key) => {
+    return Object.keys(obj).reduce<Record<string, T>>((result, key) => {
       if (obj[key] != null) {
         result[key] = obj[key];
       }
@@ -293,12 +293,12 @@ const utils = {
    * becomes
    * {'Foo-Bar': 'hi'}
    */
-  normalizeHeaders: (obj: Record<string, unknown>): Record<string, unknown> => {
+  normalizeHeaders: (obj: RequestHeaders): RequestHeaders => {
     if (!(obj && typeof obj === 'object')) {
       return obj;
     }
 
-    return Object.keys(obj).reduce((result, header) => {
+    return Object.keys(obj).reduce<RequestHeaders>((result, header) => {
       result[utils.normalizeHeader(header)] = obj[header];
       return result;
     }, {});
@@ -321,7 +321,7 @@ const utils = {
    * Determine if file data is a derivative of EventEmitter class.
    * https://nodejs.org/api/events.html#events_events
    */
-  checkForStream: (obj): boolean => {
+  checkForStream: (obj: {file?: {data: unknown}}): boolean => {
     if (obj.file && obj.file.data) {
       return obj.file.data instanceof EventEmitter;
     }
@@ -398,9 +398,9 @@ const utils = {
   flattenAndStringify: (
     data: Record<string, unknown>
   ): Record<string, unknown> => {
-    const result = {};
+    const result: RequestData = {};
 
-    const step = (obj, prevKey) => {
+    const step = (obj: RequestData, prevKey: string): void => {
       Object.keys(obj).forEach((key) => {
         const value = obj[key];
 
@@ -412,7 +412,7 @@ const utils = {
             !Object.prototype.hasOwnProperty.call(value, 'data')
           ) {
             // Non-buffer non-file Objects are recursively flattened
-            return step(value, newKey);
+            return step(value as RequestData, newKey);
           } else {
             // Buffers and file objects are stored without modification
             result[newKey] = value;

From 263f65c808443466183d753d4c314280bf678918 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 12:01:57 -0800
Subject: [PATCH 07/14] few more types

---
 src/ResourceNamespace.ts | 17 ++++++++++++-----
 src/StripeMethod.ts      |  2 +-
 src/Types.d.ts           |  9 +++++++--
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/ResourceNamespace.ts b/src/ResourceNamespace.ts
index c4b6c5566d..b4d5238c7a 100644
--- a/src/ResourceNamespace.ts
+++ b/src/ResourceNamespace.ts
@@ -1,19 +1,26 @@
 // ResourceNamespace allows you to create nested resources, i.e. `stripe.issuing.cards`.
 // It also works recursively, so you could do i.e. `stripe.billing.invoicing.pay`.
 
-function ResourceNamespace(stripe, resources) {
+function ResourceNamespace(
+  this: StripeResourceNamespaceObject,
+  stripe: StripeObject,
+  resources: Array<StripeResourceObject>
+): void {
   for (const name in resources) {
     const camelCaseName = name[0].toLowerCase() + name.substring(1);
 
-    const resource = new resources[name](stripe);
+    const resource = new (resources[name] as any)(stripe);
 
     this[camelCaseName] = resource;
   }
 }
 
-module.exports = function(namespace, resources) {
-  return function(stripe) {
-    return new ResourceNamespace(stripe, resources);
+module.exports = function(
+  namespace: string,
+  resources: Array<StripeResourceObject>
+): (stripe: StripeObject) => StripeResourceNamespaceObject {
+  return function(stripe: StripeObject): StripeResourceNamespaceObject {
+    return new (ResourceNamespace as any)(stripe, resources);
   };
 };
 
diff --git a/src/StripeMethod.ts b/src/StripeMethod.ts
index 51c6a716ea..cfafee0a5a 100644
--- a/src/StripeMethod.ts
+++ b/src/StripeMethod.ts
@@ -19,7 +19,7 @@ const makeAutoPaginationMethods = autoPagination.makeAutoPaginationMethods;
  *  Usefully for applying transforms to data on a per-method basis.
  * @param [spec.host] Hostname for the request.
  */
-function stripeMethod(spec): (...args: any[]) => Promise<any> {
+function stripeMethod(spec: MethodSpec): (...args: any[]) => Promise<any> {
   if (spec.path !== undefined && spec.fullPath !== undefined) {
     throw new Error(
       `Method spec specified both a 'path' (${spec.path}) and a 'fullPath' (${spec.fullPath}).`
diff --git a/src/Types.d.ts b/src/Types.d.ts
index 5556ac59de..13b8546a7c 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -104,9 +104,13 @@ type UrlInterpolator = (params: Record<string, unknown>) => string;
 type AppInfo = {
   name?: string;
 } & Record<string, unknown>;
-
+type StripeResourceNamespaceObject = Record<
+  string,
+  StripeResourceObject | unknown
+>;
 type MethodSpec = {
   method: string;
+  methodType: string;
   urlParams: Array<string>;
   path?: string;
   fullPath?: string;
@@ -145,7 +149,8 @@ interface HttpClientInterface {
     timeout: number
   ) => Promise<HttpClientResponseInterface>;
 }
-type ResponseHeaders = Record<string, string>;
+type ResponseHeaderValue = string | string[];
+type ResponseHeaders = Record<string, ResponseHeaderValue>;
 interface HttpClientResponseInterface {
   getStatusCode: () => number;
   getHeaders: () => ResponseHeaders;

From 023ff6ae6019e4ddc3ca03616dd685bb732e720f Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 15:25:47 -0800
Subject: [PATCH 08/14] autopagination

---
 src/Types.d.ts        | 12 ++++++
 src/autoPagination.ts | 93 ++++++++++++++++++++++++++++++-------------
 2 files changed, 78 insertions(+), 27 deletions(-)

diff --git a/src/Types.d.ts b/src/Types.d.ts
index 13b8546a7c..9df09cf523 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -188,3 +188,15 @@ type StripeRawError = {
   source?: any;
   exception?: any;
 };
+type IterationDoneCallback = () => void;
+type IterationItemCallback = (
+  item: any,
+  next: any
+) => void | boolean | Promise<void | boolean>;
+type ListResult = {
+  data: Array<any>;
+  has_more: boolean;
+};
+type ListOptions = {
+  limit?: number;
+};
diff --git a/src/autoPagination.ts b/src/autoPagination.ts
index 0032ad77b9..43ed92f1e3 100644
--- a/src/autoPagination.ts
+++ b/src/autoPagination.ts
@@ -1,13 +1,37 @@
 import makeRequest = require('./makeRequest');
 const utils = require('./utils');
 
+type PromiseCache = {
+  currentPromise: Promise<any>;
+};
+type IterationResult = {
+  done: boolean;
+  value?: any;
+};
+type AutoPagingEach = (
+  onItem: IterationItemCallback,
+  onDone?: IterationDoneCallback
+) => Promise<void>;
+
+type AutoPagingToArray = (
+  opts: ListOptions,
+  onDone: IterationDoneCallback
+) => Promise<Array<any>>;
+
+type AutoPaginationMethods = {
+  autoPagingEach: AutoPagingEach;
+  autoPagingToArray: AutoPagingToArray;
+  next: () => Promise<void>;
+  return: () => void;
+};
+
 function makeAutoPaginationMethods(
   self: StripeResourceObject,
-  requestArgs,
-  spec,
-  firstPagePromise
-) {
-  const promiseCache = {currentPromise: null};
+  requestArgs: RequestArgs,
+  spec: MethodSpec,
+  firstPagePromise: Promise<any>
+): AutoPaginationMethods {
+  const promiseCache: PromiseCache = {currentPromise: null};
   const reverseIteration = isReverseIteration(requestArgs);
   let pagePromise = firstPagePromise;
   let i = 0;
@@ -19,9 +43,9 @@ function makeAutoPaginationMethods(
   //
   // Please note: spec.methodType === 'search' is beta functionality and is
   // subject to change/removal at any time.
-  let getNextPagePromise;
+  let getNextPagePromise: (pageResult: any) => Promise<any>;
   if (spec.methodType === 'search') {
-    getNextPagePromise = (pageResult) => {
+    getNextPagePromise = (pageResult): Promise<any> => {
       if (!pageResult.next_page) {
         throw Error(
           'Unexpected: Stripe API response does not have a well-formed `next_page` field, but `has_more` was true.'
@@ -32,7 +56,7 @@ function makeAutoPaginationMethods(
       });
     };
   } else {
-    getNextPagePromise = (pageResult) => {
+    getNextPagePromise = (pageResult): Promise<any> => {
       const lastId = getLastId(pageResult, reverseIteration);
       return makeRequest(self, requestArgs, spec, {
         [reverseIteration ? 'ending_before' : 'starting_after']: lastId,
@@ -40,7 +64,9 @@ function makeAutoPaginationMethods(
     };
   }
 
-  function iterate(pageResult) {
+  function iterate(
+    pageResult: ListResult
+  ): IterationResult | Promise<IterationResult> {
     if (
       !(
         pageResult &&
@@ -68,7 +94,7 @@ function makeAutoPaginationMethods(
     return {value: undefined, done: true};
   }
 
-  function asyncIteratorNext() {
+  function asyncIteratorNext(): Promise<any> {
     return memoizedPromise(promiseCache, (resolve, reject) => {
       return pagePromise
         .then(iterate)
@@ -80,13 +106,13 @@ function makeAutoPaginationMethods(
   const autoPagingEach = makeAutoPagingEach(asyncIteratorNext);
   const autoPagingToArray = makeAutoPagingToArray(autoPagingEach);
 
-  const autoPaginationMethods = {
+  const autoPaginationMethods: AutoPaginationMethods = {
     autoPagingEach,
     autoPagingToArray,
 
     // Async iterator functions:
     next: asyncIteratorNext,
-    return: () => {
+    return: (): any => {
       // This is required for `break`.
       return {};
     },
@@ -107,7 +133,7 @@ export = {
  * ----------------
  */
 
-function getAsyncIteratorSymbol() {
+function getAsyncIteratorSymbol(): symbol | string {
   if (typeof Symbol !== 'undefined' && Symbol.asyncIterator) {
     return Symbol.asyncIterator;
   }
@@ -115,7 +141,7 @@ function getAsyncIteratorSymbol() {
   return '@@asyncIterator';
 }
 
-function getDoneCallback(args) {
+function getDoneCallback(args: Array<any>): IterationDoneCallback {
   if (args.length < 2) {
     return undefined;
   }
@@ -139,7 +165,7 @@ function getDoneCallback(args) {
  * In addition to standard validation, this helper
  * coalesces the former forms into the latter form.
  */
-function getItemCallback(args) {
+function getItemCallback(args: Array<any>): IterationItemCallback {
   if (args.length === 0) {
     return undefined;
   }
@@ -165,13 +191,13 @@ function getItemCallback(args) {
   // 1. `.autoPagingEach((item) => { doSomething(item); return false; });`
   // 2. `.autoPagingEach(async (item) => { await doSomething(item); return false; });`
   // 3. `.autoPagingEach((item) => doSomething(item).then(() => false));`
-  return function _onItem(item, next) {
+  return function _onItem(item, next): void {
     const shouldContinue = onItem(item);
     next(shouldContinue);
   };
 }
 
-function getLastId(listResult, reverseIteration) {
+function getLastId(listResult: ListResult, reverseIteration: boolean): string {
   const lastIdx = reverseIteration ? 0 : listResult.data.length - 1;
   const lastItem = listResult.data[lastIdx];
   const lastId = lastItem && lastItem.id;
@@ -188,7 +214,10 @@ function getLastId(listResult, reverseIteration) {
  * return the same result until something has resolved
  * to prevent page-turning race conditions.
  */
-function memoizedPromise(promiseCache, cb) {
+function memoizedPromise<T>(
+  promiseCache: PromiseCache,
+  cb: (resolve: (value: T) => void, reject: (reason?: any) => void) => void
+): Promise<T> {
   if (promiseCache.currentPromise) {
     return promiseCache.currentPromise;
   }
@@ -199,8 +228,10 @@ function memoizedPromise(promiseCache, cb) {
   return promiseCache.currentPromise;
 }
 
-function makeAutoPagingEach(asyncIteratorNext) {
-  return function autoPagingEach(/* onItem?, onDone? */) {
+function makeAutoPagingEach(
+  asyncIteratorNext: () => Promise<IterationResult>
+): AutoPagingEach {
+  return function autoPagingEach(/* onItem?, onDone? */): Promise<void> {
     const args = [].slice.call(arguments);
     const onItem = getItemCallback(args);
     const onDone = getDoneCallback(args);
@@ -213,11 +244,16 @@ function makeAutoPagingEach(asyncIteratorNext) {
       onItem
     );
     return utils.callbackifyPromiseWithTimeout(autoPagePromise, onDone);
-  };
+  } as AutoPagingEach;
 }
 
-function makeAutoPagingToArray(autoPagingEach) {
-  return function autoPagingToArray(opts, onDone) {
+function makeAutoPagingToArray(
+  autoPagingEach: AutoPagingEach
+): AutoPagingToArray {
+  return function autoPagingToArray(
+    opts,
+    onDone: IterationDoneCallback
+  ): Promise<Array<any>> {
     const limit = opts && opts.limit;
     if (!limit) {
       throw Error(
@@ -230,7 +266,7 @@ function makeAutoPagingToArray(autoPagingEach) {
       );
     }
     const promise = new Promise((resolve, reject) => {
-      const items = [];
+      const items: Array<any> = [];
       autoPagingEach((item) => {
         items.push(item);
         if (items.length >= limit) {
@@ -246,9 +282,12 @@ function makeAutoPagingToArray(autoPagingEach) {
   };
 }
 
-function wrapAsyncIteratorWithCallback(asyncIteratorNext, onItem) {
+function wrapAsyncIteratorWithCallback(
+  asyncIteratorNext: () => Promise<IterationResult>,
+  onItem: IterationItemCallback
+): Promise<void> {
   return new Promise<void>((resolve, reject) => {
-    function handleIteration(iterResult) {
+    function handleIteration(iterResult: IterationResult): Promise<any> {
       if (iterResult.done) {
         resolve();
         return;
@@ -275,7 +314,7 @@ function wrapAsyncIteratorWithCallback(asyncIteratorNext, onItem) {
   });
 }
 
-function isReverseIteration(requestArgs) {
+function isReverseIteration(requestArgs: RequestArgs): boolean {
   const args = [].slice.call(requestArgs);
   const dataFromArgs = utils.getDataFromArgs(args);
 

From 3988b685758f55e5bebcec87fec7b0152df5a5eb Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 15:55:18 -0800
Subject: [PATCH 09/14] types everywhere

---
 .eslintrc.js               |  2 +-
 src/StripeResource.ts      | 24 ++++++++++++++--------
 src/Types.d.ts             | 26 ++++++++++++++++++++----
 src/autoPagination.ts      |  5 ++++-
 src/multipart.ts           | 41 ++++++++++++++++++++++----------------
 src/net/FetchHttpClient.ts |  2 ++
 src/utils.ts               |  2 +-
 7 files changed, 70 insertions(+), 32 deletions(-)

diff --git a/.eslintrc.js b/.eslintrc.js
index d10ac49cb3..05679266e1 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -265,7 +265,7 @@ module.exports = {
         '@typescript-eslint/no-empty-interface': 0,
         '@typescript-eslint/no-unused-vars': 0,
         '@typescript-eslint/triple-slash-reference': 0,
-        '@typescript-eslint/ban-ts-ignore': 'off',
+        '@typescript-eslint/ban-ts-comment': 'off',
         '@typescript-eslint/no-empty-function': 0,
         '@typescript-eslint/camelcase': 0,
         '@typescript-eslint/no-explicit-any': 0,
diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index 4f8a68a996..2cccbd7af5 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -114,7 +114,13 @@ StripeResource.prototype = {
   // DEPRECATED: Here for backcompat in case users relied on this.
   wrapTimeout: utils.callbackifyPromiseWithTimeout,
 
-  _timeoutHandler(timeout: number, req, callback): () => void {
+  // eslint-disable-next-line no-warning-comments
+  // TODO: Unused?
+  _timeoutHandler(
+    timeout: number,
+    req: any,
+    callback: RequestCallback
+  ): () => void {
     return (): void => {
       const timeoutErr = new TypeError('ETIMEDOUT');
       (timeoutErr as any).code = 'ETIMEDOUT';
@@ -176,11 +182,11 @@ StripeResource.prototype = {
   _streamingResponseHandler(
     requestEvent: RequestEvent,
     callback: RequestCallback
-  ) {
-    return (res: HttpClientResponseInterface) => {
+  ): (res: HttpClientResponseInterface) => RequestCallbackReturn {
+    return (res: HttpClientResponseInterface): RequestCallbackReturn => {
       const headers = res.getHeaders();
 
-      const streamCompleteCallback = () => {
+      const streamCompleteCallback = (): void => {
         const responseEvent = this._makeResponseEvent(
           requestEvent,
           res.getStatusCode(),
@@ -261,7 +267,7 @@ StripeResource.prototype = {
             throw new StripeAPIError({
               message: 'Invalid JSON received from the Stripe API',
               exception: e,
-              requestId: headers['request-id'],
+              requestId: headers['request-id'] as string,
             });
           }
         )
@@ -313,7 +319,7 @@ StripeResource.prototype = {
     res: HttpClientResponseInterface,
     numRetries: number,
     maxRetries: number,
-    error?
+    error?: {code: number}
   ): boolean {
     if (
       error &&
@@ -514,7 +520,7 @@ StripeResource.prototype = {
     auth: string,
     options: RequestOptions = {},
     callback: RequestCallback
-  ) {
+  ): void {
     let requestData: string;
 
     const retryRequest = (
@@ -585,6 +591,7 @@ StripeResource.prototype = {
               apiVersion,
               headers,
               requestRetries,
+              // @ts-ignore
               res.getHeaders()['retry-after']
             );
           } else if (options.streaming && res.getStatusCode() < 400) {
@@ -593,7 +600,7 @@ StripeResource.prototype = {
             return this._jsonResponseHandler(requestEvent, callback)(res);
           }
         })
-        .catch((error) => {
+        .catch((error: HttpClientResponseError) => {
           if (this._shouldRetry(null, requestRetries, maxRetries, error)) {
             return retryRequest(
               makeRequest,
@@ -612,6 +619,7 @@ StripeResource.prototype = {
                 message: isTimeoutError
                   ? `Request aborted due to timeout being reached (${timeout}ms)`
                   : this._generateConnectionErrorMessage(requestRetries),
+                // @ts-ignore
                 detail: error,
               })
             );
diff --git a/src/Types.d.ts b/src/Types.d.ts
index 9df09cf523..95f2bea300 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -44,13 +44,14 @@ type StripeResourceObject = {
     auth: string,
     options: RequestOptions,
     callback: RequestCallback
-  ) => Promise<any>;
+  ) => void;
 };
+type RequestCallbackReturn = any;
 type RequestCallback = (
   this: StripeResourceObject | void,
   error: Error,
   response?: any
-) => void;
+) => RequestCallbackReturn;
 
 type RequestEvent = {
   api_version?: string;
@@ -99,6 +100,23 @@ type UserProvidedConfig = {
 type HttpHeaderValue = string | number | string[];
 type RequestHeaders = Record<string, string | number | string[]>;
 type RequestData = Record<string, unknown>;
+type MultipartRequestData = RequestData | StreamingFile | BufferedFile;
+
+type BufferedFile = {
+  name: string;
+  type: string;
+  file: {
+    data: Buffer;
+  };
+};
+
+type StreamingFile = {
+  name: string;
+  type: string;
+  file: {
+    data: import('events').EventEmitter;
+  };
+};
 type RequestArgs = Array<any>;
 type UrlInterpolator = (params: Record<string, unknown>) => string;
 type AppInfo = {
@@ -197,6 +215,6 @@ type ListResult = {
   data: Array<any>;
   has_more: boolean;
 };
-type ListOptions = {
-  limit?: number;
+type HttpClientResponseError = {
+  code: number;
 };
diff --git a/src/autoPagination.ts b/src/autoPagination.ts
index 43ed92f1e3..083e1bedd0 100644
--- a/src/autoPagination.ts
+++ b/src/autoPagination.ts
@@ -13,8 +13,11 @@ type AutoPagingEach = (
   onDone?: IterationDoneCallback
 ) => Promise<void>;
 
+type AutoPagingToArrayOptions = {
+  limit?: number;
+};
 type AutoPagingToArray = (
-  opts: ListOptions,
+  opts: AutoPagingToArrayOptions,
   onDone: IterationDoneCallback
 ) => Promise<Array<any>>;
 
diff --git a/src/multipart.ts b/src/multipart.ts
index 3aa6a7f91b..e7b4af248f 100644
--- a/src/multipart.ts
+++ b/src/multipart.ts
@@ -3,18 +3,26 @@ import _Error = require('./Error');
 const {StripeError} = _Error;
 
 class StreamProcessingError extends StripeError {}
-
+type MultipartCallbackReturn = any;
+type MultipartCallback = (
+  error: Error,
+  data: Buffer | string
+) => MultipartCallbackReturn;
 // Method for formatting HTTP body for the multipart/form-data specification
 // Mostly taken from Fermata.js
 // https://github.com/natevw/fermata/blob/5d9732a33d776ce925013a265935facd1626cc88/fermata.js#L315-L343
-const multipartDataGenerator = (method, data, headers) => {
+const multipartDataGenerator = (
+  method: string,
+  data: MultipartRequestData,
+  headers: RequestHeaders
+): Buffer => {
   const segno = (
     Math.round(Math.random() * 1e16) + Math.round(Math.random() * 1e16)
   ).toString();
   headers['Content-Type'] = `multipart/form-data; boundary=${segno}`;
   let buffer = Buffer.alloc(0);
 
-  function push(l: Buffer | string) {
+  function push(l: any): void {
     const prevBuffer = buffer;
     const newBuffer = l instanceof Buffer ? l : Buffer.from(l);
     buffer = Buffer.alloc(prevBuffer.length + newBuffer.length + 2);
@@ -23,7 +31,7 @@ const multipartDataGenerator = (method, data, headers) => {
     buffer.write('\r\n', buffer.length - 2);
   }
 
-  function q(s) {
+  function q(s: string): string {
     return `"${s.replace(/"|"/g, '%22').replace(/\r\n|\r|\n/g, ' ')}"`;
   }
 
@@ -33,11 +41,9 @@ const multipartDataGenerator = (method, data, headers) => {
     const v = flattenedData[k];
     push(`--${segno}`);
     if (Object.prototype.hasOwnProperty.call(v, 'data')) {
-      // eslint-disable-next-line no-warning-comments
-      // TODO: I don't think we ever hit this branch
       const typedEntry: {
         name: string;
-        data: string;
+        data: BufferedFile;
         type: string;
       } = v as any;
       push(
@@ -61,17 +67,18 @@ const multipartDataGenerator = (method, data, headers) => {
 
 const streamProcessor = (
   method: string,
-  data: RequestData,
+  data: StreamingFile,
   headers: RequestHeaders,
-  callback
-) => {
-  const bufferArray = [];
+  callback: MultipartCallback
+): void => {
+  const bufferArray: Array<Buffer> = [];
   data.file.data
-    .on('data', (line) => {
+    .on('data', (line: Buffer) => {
       bufferArray.push(line);
     })
     .once('end', () => {
-      const bufferData = Object.assign({}, data);
+      // @ts-ignore
+      const bufferData: BufferedFile = Object.assign({}, data);
       bufferData.file.data = Buffer.concat(bufferArray);
       const buffer = multipartDataGenerator(method, bufferData, headers);
       callback(null, buffer);
@@ -90,10 +97,10 @@ const streamProcessor = (
 
 const multipartRequestDataProcessor = (
   method: string,
-  data: RequestData,
+  data: MultipartRequestData,
   headers: RequestHeaders,
-  callback
-) => {
+  callback: MultipartCallback
+): MultipartCallbackReturn => {
   data = data || {};
 
   if (method !== 'POST') {
@@ -102,7 +109,7 @@ const multipartRequestDataProcessor = (
 
   const isStream = utils.checkForStream(data);
   if (isStream) {
-    return streamProcessor(method, data, headers, callback);
+    return streamProcessor(method, data as StreamingFile, headers, callback);
   }
 
   const buffer = multipartDataGenerator(method, data, headers);
diff --git a/src/net/FetchHttpClient.ts b/src/net/FetchHttpClient.ts
index 6a3f845986..1e3d7ca275 100644
--- a/src/net/FetchHttpClient.ts
+++ b/src/net/FetchHttpClient.ts
@@ -52,7 +52,9 @@ class FetchHttpClient extends HttpClient implements HttpClientInterface {
     const fetchFn = this._fetchFn || fetch;
     const fetchPromise = fetchFn(url.toString(), {
       method,
+      // @ts-ignore
       headers,
+      // @ts-ignore
       body,
     });
 
diff --git a/src/utils.ts b/src/utils.ts
index 75dc3017c8..325849d2c5 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -396,7 +396,7 @@ const utils = {
 
   // For use in multipart requests
   flattenAndStringify: (
-    data: Record<string, unknown>
+    data: MultipartRequestData
   ): Record<string, unknown> => {
     const result: RequestData = {};
 

From 827b3dba948ef8fceaff79abcefd2b20976368cb Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 15:56:14 -0800
Subject: [PATCH 10/14] more

---
 lib/Error.js               | 1 +
 lib/StripeResource.js      | 7 ++++++-
 lib/Webhooks.js            | 2 ++
 lib/multipart.js           | 3 +--
 lib/net/FetchHttpClient.js | 2 ++
 lib/stripe.js              | 1 +
 src/stripe.ts              | 1 +
 7 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/Error.js b/lib/Error.js
index a50ccab948..27a73f84ca 100644
--- a/lib/Error.js
+++ b/lib/Error.js
@@ -1,4 +1,5 @@
 'use strict';
+/* eslint-disable camelcase */
 /**
  * StripeError is the base error from which all other more specific Stripe errors derive.
  * Specifically for errors returned from Stripe's REST API.
diff --git a/lib/StripeResource.js b/lib/StripeResource.js
index bfced38996..322c1389e2 100644
--- a/lib/StripeResource.js
+++ b/lib/StripeResource.js
@@ -42,6 +42,7 @@ function StripeResource(stripe, deprecatedUrlData) {
   this.initialize(...arguments);
 }
 StripeResource.prototype = {
+  _stripe: null,
   path: '',
   // Methods that don't use the API's default '/v1' path can override it with this setting.
   basePath: null,
@@ -90,6 +91,8 @@ StripeResource.prototype = {
   },
   // DEPRECATED: Here for backcompat in case users relied on this.
   wrapTimeout: utils.callbackifyPromiseWithTimeout,
+  // eslint-disable-next-line no-warning-comments
+  // TODO: Unused?
   _timeoutHandler(timeout, req, callback) {
     return () => {
       const timeoutErr = new TypeError('ETIMEDOUT');
@@ -234,7 +237,7 @@ StripeResource.prototype = {
       requestRetries > 0 ? ` Request was retried ${requestRetries} times.` : ''
     }`;
   },
-  _errorHandler(req, requestRetries, callback) {
+  _errorHandler(res, requestRetries, callback) {
     return (message, detail) => {
       callback.call(
         this,
@@ -470,6 +473,7 @@ StripeResource.prototype = {
               apiVersion,
               headers,
               requestRetries,
+              // @ts-ignore
               res.getHeaders()['retry-after']
             );
           } else if (options.streaming && res.getStatusCode() < 400) {
@@ -496,6 +500,7 @@ StripeResource.prototype = {
                 message: isTimeoutError
                   ? `Request aborted due to timeout being reached (${timeout}ms)`
                   : this._generateConnectionErrorMessage(requestRetries),
+                // @ts-ignore
                 detail: error,
               })
             );
diff --git a/lib/Webhooks.js b/lib/Webhooks.js
index f7570b3946..36acd5bbe2 100644
--- a/lib/Webhooks.js
+++ b/lib/Webhooks.js
@@ -13,6 +13,7 @@ const Webhook = {
       tolerance || Webhook.DEFAULT_TOLERANCE,
       cryptoProvider
     );
+    // @ts-ignore
     const jsonPayload = JSON.parse(payload);
     return jsonPayload;
   },
@@ -30,6 +31,7 @@ const Webhook = {
       tolerance || Webhook.DEFAULT_TOLERANCE,
       cryptoProvider
     );
+    // @ts-ignore
     const jsonPayload = JSON.parse(payload);
     return jsonPayload;
   },
diff --git a/lib/multipart.js b/lib/multipart.js
index cf7f6d9e53..29e53c8363 100644
--- a/lib/multipart.js
+++ b/lib/multipart.js
@@ -28,8 +28,6 @@ const multipartDataGenerator = (method, data, headers) => {
     const v = flattenedData[k];
     push(`--${segno}`);
     if (Object.prototype.hasOwnProperty.call(v, 'data')) {
-      // eslint-disable-next-line no-warning-comments
-      // TODO: I don't think we ever hit this branch
       const typedEntry = v;
       push(
         `Content-Disposition: form-data; name=${q(k)}; filename=${q(
@@ -55,6 +53,7 @@ const streamProcessor = (method, data, headers, callback) => {
       bufferArray.push(line);
     })
     .once('end', () => {
+      // @ts-ignore
       const bufferData = Object.assign({}, data);
       bufferData.file.data = Buffer.concat(bufferArray);
       const buffer = multipartDataGenerator(method, bufferData, headers);
diff --git a/lib/net/FetchHttpClient.js b/lib/net/FetchHttpClient.js
index 195b1bb0c6..355824001a 100644
--- a/lib/net/FetchHttpClient.js
+++ b/lib/net/FetchHttpClient.js
@@ -44,7 +44,9 @@ class FetchHttpClient extends HttpClient {
     const fetchFn = this._fetchFn || fetch;
     const fetchPromise = fetchFn(url.toString(), {
       method,
+      // @ts-ignore
       headers,
+      // @ts-ignore
       body,
     });
     // The Fetch API does not support passing in a timeout natively, so a
diff --git a/lib/stripe.js b/lib/stripe.js
index fc1e5bc95e..4de52b6ad1 100644
--- a/lib/stripe.js
+++ b/lib/stripe.js
@@ -108,6 +108,7 @@ function Stripe(key, config = {}) {
   this._prevRequestMetrics = [];
   this._enableTelemetry = props.telemetry !== false;
   // Expose StripeResource on the instance too
+  // @ts-ignore
   this.StripeResource = Stripe.StripeResource;
 }
 Stripe.errors = _Error;
diff --git a/src/stripe.ts b/src/stripe.ts
index f40acf52df..721d6d451e 100644
--- a/src/stripe.ts
+++ b/src/stripe.ts
@@ -132,6 +132,7 @@ function Stripe(this: StripeObject, key: string, config = {}): void {
   this._enableTelemetry = props.telemetry !== false;
 
   // Expose StripeResource on the instance too
+  // @ts-ignore
   this.StripeResource = Stripe.StripeResource;
 }
 

From 5ecdff2217b30afaed12e5ef3b24a770dca94610 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Wed, 9 Nov 2022 16:01:54 -0800
Subject: [PATCH 11/14] even more types

---
 src/StripeMethod.ts   |  2 +-
 src/StripeResource.ts | 17 ++++++++---------
 src/Types.d.ts        |  6 ++++++
 src/utils.ts          |  5 +++--
 tsconfig.json         |  1 +
 5 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/StripeMethod.ts b/src/StripeMethod.ts
index cfafee0a5a..3a99651f4e 100644
--- a/src/StripeMethod.ts
+++ b/src/StripeMethod.ts
@@ -25,7 +25,7 @@ function stripeMethod(spec: MethodSpec): (...args: any[]) => Promise<any> {
       `Method spec specified both a 'path' (${spec.path}) and a 'fullPath' (${spec.fullPath}).`
     );
   }
-  return function(...args: any[]): Promise<any> {
+  return function(this: StripeResourceObject, ...args: any[]): Promise<any> {
     const callback = typeof args[args.length - 1] == 'function' && args.pop();
 
     spec.urlParams = utils.extractUrlParams(
diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index 2cccbd7af5..221abe0a02 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -25,7 +25,11 @@ const MAX_RETRY_AFTER_WAIT = 60;
 /**
  * Encapsulates request logic for a Stripe Resource
  */
-function StripeResource(stripe: StripeObject, deprecatedUrlData?: never): void {
+function StripeResource(
+  this: StripeResourceObject,
+  stripe: StripeObject,
+  deprecatedUrlData?: never
+): void {
   this._stripe = stripe;
   if (deprecatedUrlData) {
     throw new Error(
@@ -34,19 +38,14 @@ function StripeResource(stripe: StripeObject, deprecatedUrlData?: never): void {
   }
 
   this.basePath = utils.makeURLInterpolator(
+    // @ts-ignore changing type of basePath
     this.basePath || stripe.getApiField('basePath')
   );
+  // @ts-ignore changing type of path
   this.resourcePath = this.path;
+  // @ts-ignore changing type of path
   this.path = utils.makeURLInterpolator(this.path);
 
-  // DEPRECATED: This was kept for backwards compatibility in case users were
-  // using this, but basic methods are now explicitly defined on a resource.
-  if (this.includeBasic) {
-    this.includeBasic.forEach(function(methodName: string) {
-      this[methodName] = StripeResource.BASIC_METHODS[methodName];
-    }, this);
-  }
-
   this.initialize(...arguments);
 }
 
diff --git a/src/Types.d.ts b/src/Types.d.ts
index 95f2bea300..e9033e9ac3 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -31,6 +31,10 @@ type StripeObject = {
   _getPropsFromConfig: (config: Record<string, unknown>) => UserProvidedConfig;
 };
 type StripeResourceObject = {
+  _stripe: StripeObject;
+  basePath: UrlInterpolator;
+  path: UrlInterpolator;
+  resourcePath: string;
   createResourcePathWithSymbols: (path: string) => string;
   createFullPath: (
     interpolator: UrlInterpolator,
@@ -45,6 +49,8 @@ type StripeResourceObject = {
     options: RequestOptions,
     callback: RequestCallback
   ) => void;
+  initialize: (...args: Array<any>) => void;
+  prototype: StripeResourceObject;
 };
 type RequestCallbackReturn = any;
 type RequestCallback = (
diff --git a/src/utils.ts b/src/utils.ts
index 325849d2c5..ad933b3646 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -222,12 +222,13 @@ const utils = {
   /**
    * Provide simple "Class" extension mechanism
    */
-  protoExtend(sub: any): (...args: any[]) => void {
+  protoExtend(this: StripeResourceObject, sub: any): (...args: any[]) => void {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const Super = this;
     const Constructor = Object.prototype.hasOwnProperty.call(sub, 'constructor')
       ? sub.constructor
-      : function(...args: any[]): void {
+      : function(this: StripeResourceObject, ...args: any[]): void {
+          // @ts-ignore
           Super.apply(this, args);
         };
 
diff --git a/tsconfig.json b/tsconfig.json
index 2f0736a2a1..8c17887f26 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,6 +7,7 @@
     "checkJs": false,
     "alwaysStrict": true,
     "noImplicitAny": true,
+    "noImplicitThis": true
   },
   "include": ["./src/**/*"]
 }

From bf9b8561769c7fb689e9f92ef2c97d9371a55343 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Thu, 10 Nov 2022 07:34:23 -0800
Subject: [PATCH 12/14] strict

---
 src/Error.ts               |  7 +++--
 src/StripeResource.ts      | 37 +++++++++++++------------
 src/Types.d.ts             | 34 +++++++++++------------
 src/Webhooks.ts            | 56 ++++++++++++++++++++++++++++++++------
 src/autoPagination.ts      | 19 ++++++++++---
 src/multipart.ts           |  4 +--
 src/net/FetchHttpClient.ts | 11 ++++----
 src/net/NodeHttpClient.ts  |  1 +
 src/stripe.ts              | 13 ++++++---
 src/utils.ts               | 24 +++++++++-------
 tsconfig.json              |  3 +-
 11 files changed, 138 insertions(+), 71 deletions(-)

diff --git a/src/Error.ts b/src/Error.ts
index d4fef7bb93..b5489fe001 100644
--- a/src/Error.ts
+++ b/src/Error.ts
@@ -7,9 +7,9 @@ class StripeError extends Error {
   readonly message: string;
   readonly type: string;
   readonly raw: unknown;
-  readonly rawType: RawErrorType;
-  readonly headers: {[header: string]: string};
-  readonly requestId: string;
+  readonly rawType?: RawErrorType;
+  readonly headers?: {[header: string]: string};
+  readonly requestId?: string;
 
   readonly code?: string;
   readonly doc_url?: string;
@@ -38,6 +38,7 @@ class StripeError extends Error {
     this.headers = raw.headers;
     this.requestId = raw.requestId;
     this.statusCode = raw.statusCode;
+    // @ts-ignore
     this.message = raw.message;
 
     this.charge = raw.charge;
diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index 221abe0a02..9f89af8fab 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -12,16 +12,6 @@ const {
 
 const {HttpClient} = require('./net/HttpClient');
 
-// Provide extension mechanism for Stripe Resource Sub-Classes
-StripeResource.extend = utils.protoExtend;
-
-// Expose method-creator & prepared (basic) methods
-StripeResource.method = require('./StripeMethod');
-StripeResource.BASIC_METHODS = require('./StripeMethod.basic');
-
-StripeResource.MAX_BUFFERED_REQUEST_METRICS = 100;
-const MAX_RETRY_AFTER_WAIT = 60;
-
 /**
  * Encapsulates request logic for a Stripe Resource
  */
@@ -48,9 +38,18 @@ function StripeResource(
 
   this.initialize(...arguments);
 }
+// Provide extension mechanism for Stripe Resource Sub-Classes
+StripeResource.extend = utils.protoExtend;
+
+// Expose method-creator & prepared (basic) methods
+StripeResource.method = require('./StripeMethod');
+StripeResource.BASIC_METHODS = require('./StripeMethod.basic');
+
+StripeResource.MAX_BUFFERED_REQUEST_METRICS = 100;
+const MAX_RETRY_AFTER_WAIT = 60;
 
 StripeResource.prototype = {
-  _stripe: null as StripeObject,
+  _stripe: null as StripeObject | null,
   path: '',
 
   // Methods that don't use the API's default '/v1' path can override it with this setting.
@@ -92,7 +91,7 @@ StripeResource.prototype = {
   // Creates a relative resource path with symbols left in (unlike
   // createFullPath which takes some data to replace them with). For example it
   // might produce: /invoices/{id}
-  createResourcePathWithSymbols(pathWithSymbols: string): string {
+  createResourcePathWithSymbols(pathWithSymbols: string | null): string {
     // If there is no path beyond the resource path, we want to produce just
     // /<resource path> rather than /<resource path>/.
     if (pathWithSymbols) {
@@ -387,8 +386,8 @@ StripeResource.prototype = {
     sleepSeconds = Math.max(initialNetworkRetryDelay, sleepSeconds);
 
     // And never sleep less than the time the API asks us to wait, assuming it's a reasonable ask.
-    if (Number.isInteger(retryAfter) && retryAfter <= MAX_RETRY_AFTER_WAIT) {
-      sleepSeconds = Math.max(sleepSeconds, retryAfter);
+    if (Number.isInteger(retryAfter) && retryAfter! <= MAX_RETRY_AFTER_WAIT) {
+      sleepSeconds = Math.max(sleepSeconds, retryAfter!);
     }
 
     return sleepSeconds * 1000;
@@ -402,7 +401,10 @@ StripeResource.prototype = {
       : this._stripe.getMaxNetworkRetries();
   },
 
-  _defaultIdempotencyKey(method: string, settings: RequestSettings): string {
+  _defaultIdempotencyKey(
+    method: string,
+    settings: RequestSettings
+  ): string | null {
     // If this is a POST and we allow multiple retries, ensure an idempotency key.
     const maxRetries = this._getMaxNetworkRetries(settings);
 
@@ -481,7 +483,7 @@ StripeResource.prototype = {
     return `Stripe/v1 NodeBindings/${packageVersion} ${appInfo}`.trim();
   },
 
-  _getTelemetryHeader(): string {
+  _getTelemetryHeader(): string | undefined {
     if (
       this._stripe.getTelemetryEnabled() &&
       this._stripe._prevRequestMetrics.length > 0
@@ -567,6 +569,7 @@ StripeResource.prototype = {
 
       const requestStartTime = Date.now();
 
+      // @ts-ignore
       const requestEvent: RequestEvent = utils.removeNullish({
         api_version: apiVersion,
         account: headers['Stripe-Account'],
@@ -626,7 +629,7 @@ StripeResource.prototype = {
         });
     };
 
-    const prepareAndMakeRequest = (error: Error, data: string): void => {
+    const prepareAndMakeRequest = (error: Error | null, data: string): void => {
       if (error) {
         return callback(error);
       }
diff --git a/src/Types.d.ts b/src/Types.d.ts
index e9033e9ac3..b7de25d967 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -4,7 +4,7 @@ type StripeObject = {
   off: any;
   once: any;
   VERSION: string;
-  StripeResource: StripeResourceObject;
+  StripeResource: typeof StripeResource;
   errors: any;
   webhooks: any;
   getApiField: <T = string>(name: string) => T;
@@ -13,7 +13,7 @@ type StripeObject = {
   _setApiKey: (apiKey: string) => void;
   _prevRequestMetrics: number[];
   _api: {
-    auth: string;
+    auth: string | null;
     host: string;
     port: string | number;
     protocol: string;
@@ -24,7 +24,7 @@ type StripeObject = {
     agent: string;
     httpClient: any;
     dev: boolean;
-    stripeAccount: string;
+    stripeAccount: string | null;
   };
   _emitter: import('events').EventEmitter;
   _enableTelemetry: boolean;
@@ -35,7 +35,7 @@ type StripeResourceObject = {
   basePath: UrlInterpolator;
   path: UrlInterpolator;
   resourcePath: string;
-  createResourcePathWithSymbols: (path: string) => string;
+  createResourcePathWithSymbols: (path: string | null | undefined) => string;
   createFullPath: (
     interpolator: UrlInterpolator,
     urlData: RequestData
@@ -50,12 +50,11 @@ type StripeResourceObject = {
     callback: RequestCallback
   ) => void;
   initialize: (...args: Array<any>) => void;
-  prototype: StripeResourceObject;
 };
 type RequestCallbackReturn = any;
 type RequestCallback = (
   this: StripeResourceObject | void,
-  error: Error,
+  error: Error | null,
   response?: any
 ) => RequestCallbackReturn;
 
@@ -65,7 +64,7 @@ type RequestEvent = {
   idempotency_key?: string;
   method?: string;
   path?: string;
-  request_start_time?: number;
+  request_start_time: number;
 };
 
 type ResponseEvent = {
@@ -173,6 +172,9 @@ interface HttpClientInterface {
     timeout: number
   ) => Promise<HttpClientResponseInterface>;
 }
+type HttpClientResponseError = {
+  code: number;
+};
 type ResponseHeaderValue = string | string[];
 type ResponseHeaders = Record<string, ResponseHeaderValue>;
 interface HttpClientResponseInterface {
@@ -212,15 +214,13 @@ type StripeRawError = {
   source?: any;
   exception?: any;
 };
-type IterationDoneCallback = () => void;
-type IterationItemCallback = (
-  item: any,
-  next: any
-) => void | boolean | Promise<void | boolean>;
-type ListResult = {
-  data: Array<any>;
-  has_more: boolean;
+
+type StripeResourceConstructor = {
+  new (stripe: StripeObject, deprecatedUrlData?: never): StripeResourceObject;
 };
-type HttpClientResponseError = {
-  code: number;
+declare const StripeResource: StripeResourceConstructor;
+
+type StripeConstructor = {
+  new (key: string, config: Record<string, unknown>): StripeObject;
 };
+declare const Stripe: StripeConstructor;
diff --git a/src/Webhooks.ts b/src/Webhooks.ts
index 68c698d747..955da33bb6 100644
--- a/src/Webhooks.ts
+++ b/src/Webhooks.ts
@@ -2,7 +2,6 @@ import utils = require('./utils');
 import _Error = require('./Error');
 const {StripeError, StripeSignatureVerificationError} = _Error;
 
-type WebhookPayload = string | Buffer;
 type WebhookHeader = string | Buffer;
 type WebhookParsedHeader = {
   signatures: Array<string>;
@@ -21,12 +20,49 @@ type WebhookTestHeaderOptions = {
   signature: string;
   cryptoProvider: StripeCryptoProvider;
 };
+
 type WebhookEvent = Record<string, unknown>;
+type WebhookPayload = string | Buffer;
+type WebhookSignatureObject = {
+  verifyHeader: (
+    encodedPayload: WebhookPayload,
+    encodedHeader: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
+  ) => boolean;
+  verifyHeaderAsync: (
+    encodedPayload: WebhookPayload,
+    encodedHeader: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
+  ) => Promise<boolean>;
+};
+type WebhookObject = {
+  DEFAULT_TOLERANCE: number;
+  signature: WebhookSignatureObject;
+  constructEvent: (
+    payload: WebhookPayload,
+    header: WebhookHeader,
+    secret: string,
+    tolerance: null,
+    cryptoProvider: StripeCryptoProvider
+  ) => WebhookEvent;
+  constructEventAsync: (
+    payload: WebhookPayload,
+    header: WebhookHeader,
+    secret: string,
+    tolerance: number,
+    cryptoProvider: StripeCryptoProvider
+  ) => Promise<WebhookEvent>;
+  generateTestHeaderString: (opts: WebhookTestHeaderOptions) => string;
+};
 
-const Webhook = {
+const Webhook: WebhookObject = {
   DEFAULT_TOLERANCE: 300, // 5 minutes
-  signature: null as typeof signature,
-
+  // @ts-ignore
+  signature: null,
   constructEvent(
     payload: WebhookPayload,
     header: WebhookHeader,
@@ -239,6 +275,7 @@ function validateComputedSignature(
   tolerance: number
 ): boolean {
   const signatureFound = !!details.signatures.filter(
+    // @ts-ignore
     utils.secureCompare.bind(utils, expectedSignature)
   ).length;
 
@@ -272,12 +309,15 @@ function validateComputedSignature(
   return true;
 }
 
-function parseHeader(header: string, scheme: string): WebhookParsedHeader {
+function parseHeader(
+  header: string,
+  scheme: string
+): WebhookParsedHeader | null {
   if (typeof header !== 'string') {
     return null;
   }
 
-  return header.split(',').reduce(
+  return header.split(',').reduce<WebhookParsedHeader>(
     (accum, item) => {
       const kv = item.split('=');
 
@@ -298,7 +338,7 @@ function parseHeader(header: string, scheme: string): WebhookParsedHeader {
   );
 }
 
-let webhooksNodeCryptoProviderInstance = null as StripeCryptoProvider;
+let webhooksNodeCryptoProviderInstance: StripeCryptoProvider | null = null;
 
 /**
  * Lazily instantiate a NodeCryptoProvider instance. This is a stateless object
@@ -309,7 +349,7 @@ function getNodeCryptoProvider(): StripeCryptoProvider {
     const NodeCryptoProvider = require('./crypto/NodeCryptoProvider');
     webhooksNodeCryptoProviderInstance = new NodeCryptoProvider();
   }
-  return webhooksNodeCryptoProviderInstance;
+  return webhooksNodeCryptoProviderInstance!;
 }
 
 Webhook.signature = signature;
diff --git a/src/autoPagination.ts b/src/autoPagination.ts
index 083e1bedd0..81ca6369b1 100644
--- a/src/autoPagination.ts
+++ b/src/autoPagination.ts
@@ -2,12 +2,22 @@ import makeRequest = require('./makeRequest');
 const utils = require('./utils');
 
 type PromiseCache = {
-  currentPromise: Promise<any>;
+  currentPromise: Promise<any> | undefined | null;
 };
 type IterationResult = {
   done: boolean;
   value?: any;
 };
+type IterationDoneCallback = () => void;
+type IterationItemCallback = (
+  item: any,
+  next: any
+) => void | boolean | Promise<void | boolean>;
+type ListResult = {
+  data: Array<any>;
+  // eslint-disable-next-line camelcase
+  has_more: boolean;
+};
 type AutoPagingEach = (
   onItem: IterationItemCallback,
   onDone?: IterationDoneCallback
@@ -144,7 +154,7 @@ function getAsyncIteratorSymbol(): symbol | string {
   return '@@asyncIterator';
 }
 
-function getDoneCallback(args: Array<any>): IterationDoneCallback {
+function getDoneCallback(args: Array<any>): IterationDoneCallback | undefined {
   if (args.length < 2) {
     return undefined;
   }
@@ -168,7 +178,7 @@ function getDoneCallback(args: Array<any>): IterationDoneCallback {
  * In addition to standard validation, this helper
  * coalesces the former forms into the latter form.
  */
-function getItemCallback(args: Array<any>): IterationItemCallback {
+function getItemCallback(args: Array<any>): IterationItemCallback | undefined {
   if (args.length === 0) {
     return undefined;
   }
@@ -244,6 +254,7 @@ function makeAutoPagingEach(
 
     const autoPagePromise = wrapAsyncIteratorWithCallback(
       asyncIteratorNext,
+      // @ts-ignore we might need a null check
       onItem
     );
     return utils.callbackifyPromiseWithTimeout(autoPagePromise, onDone);
@@ -290,7 +301,7 @@ function wrapAsyncIteratorWithCallback(
   onItem: IterationItemCallback
 ): Promise<void> {
   return new Promise<void>((resolve, reject) => {
-    function handleIteration(iterResult: IterationResult): Promise<any> {
+    function handleIteration(iterResult: IterationResult): Promise<any> | void {
       if (iterResult.done) {
         resolve();
         return;
diff --git a/src/multipart.ts b/src/multipart.ts
index e7b4af248f..01e91b1a37 100644
--- a/src/multipart.ts
+++ b/src/multipart.ts
@@ -5,8 +5,8 @@ const {StripeError} = _Error;
 class StreamProcessingError extends StripeError {}
 type MultipartCallbackReturn = any;
 type MultipartCallback = (
-  error: Error,
-  data: Buffer | string
+  error: Error | null,
+  data: Buffer | string | null
 ) => MultipartCallbackReturn;
 // Method for formatting HTTP body for the multipart/form-data specification
 // Mostly taken from Fermata.js
diff --git a/src/net/FetchHttpClient.ts b/src/net/FetchHttpClient.ts
index 1e3d7ca275..6e4facecee 100644
--- a/src/net/FetchHttpClient.ts
+++ b/src/net/FetchHttpClient.ts
@@ -11,7 +11,6 @@ const {HttpClient, HttpClientResponse} = _HttpClient;
  */
 class FetchHttpClient extends HttpClient implements HttpClientInterface {
   _fetchFn: typeof fetch;
-  _res: Response;
 
   constructor(fetchFn: typeof fetch) {
     super();
@@ -71,7 +70,7 @@ class FetchHttpClient extends HttpClient implements HttpClientInterface {
     // to be established followed by 20s for the body, Fetch would timeout but
     // Node would not. The more fine-grained timeout cannot be implemented with
     // fetch.
-    let pendingTimeoutId: NodeJS.Timeout;
+    let pendingTimeoutId: NodeJS.Timeout | null;
     const timeoutPromise = new Promise((_, reject) => {
       pendingTimeoutId = setTimeout(() => {
         pendingTimeoutId = null;
@@ -80,8 +79,8 @@ class FetchHttpClient extends HttpClient implements HttpClientInterface {
     });
 
     return Promise.race([fetchPromise, timeoutPromise])
-      .then((res: Response) => {
-        return new FetchHttpClientResponse(res);
+      .then((res) => {
+        return new FetchHttpClientResponse(res as Response);
       })
       .finally(() => {
         if (pendingTimeoutId) {
@@ -107,7 +106,9 @@ class FetchHttpClientResponse extends HttpClientResponse
     return this._res;
   }
 
-  toStream(streamCompleteCallback: () => void): ReadableStream<Uint8Array> {
+  toStream(
+    streamCompleteCallback: () => void
+  ): ReadableStream<Uint8Array> | null {
     // Unfortunately `fetch` does not have event handlers for when the stream is
     // completely read. We therefore invoke the streamCompleteCallback right
     // away. This callback emits a response event with metadata and completes
diff --git a/src/net/NodeHttpClient.ts b/src/net/NodeHttpClient.ts
index d337b677d1..93b37a26b5 100644
--- a/src/net/NodeHttpClient.ts
+++ b/src/net/NodeHttpClient.ts
@@ -93,6 +93,7 @@ class NodeHttpClientResponse extends HttpClientResponse
   _res: http.IncomingMessage;
 
   constructor(res: http.IncomingMessage) {
+    // @ts-ignore
     super(res.statusCode, res.headers || {});
     this._res = res;
   }
diff --git a/src/stripe.ts b/src/stripe.ts
index 721d6d451e..6e684e19c7 100644
--- a/src/stripe.ts
+++ b/src/stripe.ts
@@ -5,7 +5,7 @@ const resources = require('./resources');
 const DEFAULT_HOST = 'api.stripe.com';
 const DEFAULT_PORT = '443';
 const DEFAULT_BASE_PATH = '/v1/';
-const DEFAULT_API_VERSION = null as string;
+const DEFAULT_API_VERSION = (null as unknown) as string;
 
 const DEFAULT_TIMEOUT = 80000;
 
@@ -24,7 +24,7 @@ Stripe.USER_AGENT = {
 };
 
 /** @private */
-Stripe._UNAME_CACHE = null as Promise<string>;
+Stripe._UNAME_CACHE = null as Promise<string> | null;
 
 const MAX_NETWORK_RETRY_DELAY_SEC = 2;
 const INITIAL_NETWORK_RETRY_DELAY_SEC = 0.5;
@@ -58,7 +58,11 @@ Stripe.HttpClientResponse = HttpClientResponse;
 const CryptoProvider = require('./crypto/CryptoProvider');
 Stripe.CryptoProvider = CryptoProvider;
 
-function Stripe(this: StripeObject, key: string, config = {}): void {
+function Stripe(
+  this: StripeObject,
+  key: string,
+  config: Record<string, unknown> = {}
+): void {
   if (!(this instanceof Stripe)) {
     return new (Stripe as any)(key, config);
   }
@@ -330,7 +334,7 @@ Stripe.prototype = {
 
     info = info || {};
 
-    this._appInfo = APP_INFO_PROPERTIES.reduce(
+    this._appInfo = APP_INFO_PROPERTIES.reduce<Record<string, any>>(
       (accum: Record<string, any>, prop) => {
         if (typeof info[prop] == 'string') {
           accum = accum || {};
@@ -340,6 +344,7 @@ Stripe.prototype = {
 
         return accum;
       },
+      // @ts-ignore
       undefined
     );
   },
diff --git a/src/utils.ts b/src/utils.ts
index ad933b3646..9eb3971cc9 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -9,6 +9,7 @@ let exec = null;
 try {
   exec = require('child_process').exec;
 } catch (e) {
+  // @ts-ignore
   if (e.code !== 'MODULE_NOT_FOUND') {
     throw e;
   }
@@ -39,15 +40,15 @@ type Settings = {
 };
 
 type Options = {
-  auth?: string;
+  auth?: string | null;
   host?: string;
-  settings?: Settings;
+  settings: Settings;
   streaming?: boolean;
-  headers?: Record<string, unknown>;
+  headers: Record<string, unknown>;
 };
 
 const utils = {
-  isOptionsHash(o: unknown): boolean {
+  isOptionsHash(o: unknown): boolean | unknown {
     return (
       o &&
       typeof o === 'object' &&
@@ -93,8 +94,9 @@ const utils = {
     } as Record<string, string>;
     return (str: string): UrlInterpolator => {
       const cleanString = str.replace(/["\n\r\u2028\u2029]/g, ($0) => rc[$0]);
-      return (outputs: Record<string, undefined>): string => {
+      return (outputs: Record<string, unknown>): string => {
         return cleanString.replace(/\{([\s\S]+?)\}/g, ($0, $1) =>
+          // @ts-ignore
           encodeURIComponent(outputs[$1] || '')
         );
       };
@@ -222,13 +224,12 @@ const utils = {
   /**
    * Provide simple "Class" extension mechanism
    */
-  protoExtend(this: StripeResourceObject, sub: any): (...args: any[]) => void {
+  protoExtend(this: any, sub: any): (...args: any[]) => void {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const Super = this;
     const Constructor = Object.prototype.hasOwnProperty.call(sub, 'constructor')
       ? sub.constructor
       : function(this: StripeResourceObject, ...args: any[]): void {
-          // @ts-ignore
           Super.apply(this, args);
         };
 
@@ -331,7 +332,7 @@ const utils = {
 
   callbackifyPromiseWithTimeout: <T>(
     promise: Promise<T>,
-    callback: (error: unknown, result: T) => void
+    callback: (error: unknown, result: T | null) => void
   ): Promise<T | void> => {
     if (callback) {
       // Ensure callback is called outside of promise stack.
@@ -372,7 +373,10 @@ const utils = {
    *
    * This unifies that interface.
    */
-  safeExec: (cmd: string, cb: (error: Error, stdout: string) => void): void => {
+  safeExec: (
+    cmd: string,
+    cb: (error: unknown, stdout: string | null) => void
+  ): void => {
     // Occurs if we couldn't load the `child_process` module, which might
     // happen in certain sandboxed environments like a CloudFlare Worker.
     if (utils._exec === null) {
@@ -401,7 +405,7 @@ const utils = {
   ): Record<string, unknown> => {
     const result: RequestData = {};
 
-    const step = (obj: RequestData, prevKey: string): void => {
+    const step = (obj: RequestData, prevKey: string | null): void => {
       Object.keys(obj).forEach((key) => {
         const value = obj[key];
 
diff --git a/tsconfig.json b/tsconfig.json
index 8c17887f26..1b672e1407 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,7 +7,8 @@
     "checkJs": false,
     "alwaysStrict": true,
     "noImplicitAny": true,
-    "noImplicitThis": true
+    "noImplicitThis": true,
+    "strict": true
   },
   "include": ["./src/**/*"]
 }

From 3c3b82144b200ea7bb84c2121a745434dfb360c7 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Thu, 10 Nov 2022 07:39:15 -0800
Subject: [PATCH 13/14] more

---
 lib/Error.js              |  1 +
 lib/StripeResource.js     |  5 +++++
 lib/Webhooks.js           |  2 ++
 lib/autoPagination.js     |  1 +
 lib/net/NodeHttpClient.js |  1 +
 lib/stripe.js             | 18 +++++++++++-------
 lib/utils.js              |  2 ++
 src/StripeResource.ts     | 28 ++++++++++++++++++----------
 src/Types.d.ts            |  1 +
 tsconfig.json             |  2 +-
 10 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/lib/Error.js b/lib/Error.js
index 27a73f84ca..0b5c8ad8db 100644
--- a/lib/Error.js
+++ b/lib/Error.js
@@ -17,6 +17,7 @@ class StripeError extends Error {
     this.headers = raw.headers;
     this.requestId = raw.requestId;
     this.statusCode = raw.statusCode;
+    // @ts-ignore
     this.message = raw.message;
     this.charge = raw.charge;
     this.decline_code = raw.decline_code;
diff --git a/lib/StripeResource.js b/lib/StripeResource.js
index 322c1389e2..9a11b7d1c3 100644
--- a/lib/StripeResource.js
+++ b/lib/StripeResource.js
@@ -28,14 +28,18 @@ function StripeResource(stripe, deprecatedUrlData) {
     );
   }
   this.basePath = utils.makeURLInterpolator(
+    // @ts-ignore changing type of basePath
     this.basePath || stripe.getApiField('basePath')
   );
+  // @ts-ignore changing type of path
   this.resourcePath = this.path;
+  // @ts-ignore changing type of path
   this.path = utils.makeURLInterpolator(this.path);
   // DEPRECATED: This was kept for backwards compatibility in case users were
   // using this, but basic methods are now explicitly defined on a resource.
   if (this.includeBasic) {
     this.includeBasic.forEach(function(methodName) {
+      // @ts-ignore
       this[methodName] = StripeResource.BASIC_METHODS[methodName];
     }, this);
   }
@@ -454,6 +458,7 @@ StripeResource.prototype = {
           timeout
         );
       const requestStartTime = Date.now();
+      // @ts-ignore
       const requestEvent = utils.removeNullish({
         api_version: apiVersion,
         account: headers['Stripe-Account'],
diff --git a/lib/Webhooks.js b/lib/Webhooks.js
index 36acd5bbe2..ce6322201e 100644
--- a/lib/Webhooks.js
+++ b/lib/Webhooks.js
@@ -4,6 +4,7 @@ const _Error = require('./Error');
 const {StripeError, StripeSignatureVerificationError} = _Error;
 const Webhook = {
   DEFAULT_TOLERANCE: 300,
+  // @ts-ignore
   signature: null,
   constructEvent(payload, header, secret, tolerance, cryptoProvider) {
     this.signature.verifyHeader(
@@ -177,6 +178,7 @@ function validateComputedSignature(
   tolerance
 ) {
   const signatureFound = !!details.signatures.filter(
+    // @ts-ignore
     utils.secureCompare.bind(utils, expectedSignature)
   ).length;
   if (!signatureFound) {
diff --git a/lib/autoPagination.js b/lib/autoPagination.js
index 141afdeb49..3626ffeae3 100644
--- a/lib/autoPagination.js
+++ b/lib/autoPagination.js
@@ -182,6 +182,7 @@ function makeAutoPagingEach(asyncIteratorNext) {
     }
     const autoPagePromise = wrapAsyncIteratorWithCallback(
       asyncIteratorNext,
+      // @ts-ignore we might need a null check
       onItem
     );
     return utils.callbackifyPromiseWithTimeout(autoPagePromise, onDone);
diff --git a/lib/net/NodeHttpClient.js b/lib/net/NodeHttpClient.js
index c5712dfe2f..cf580fd63d 100644
--- a/lib/net/NodeHttpClient.js
+++ b/lib/net/NodeHttpClient.js
@@ -74,6 +74,7 @@ class NodeHttpClient extends HttpClient {
 }
 class NodeHttpClientResponse extends HttpClientResponse {
   constructor(res) {
+    // @ts-ignore
     super(res.statusCode, res.headers || {});
     this._res = res;
   }
diff --git a/lib/stripe.js b/lib/stripe.js
index 4de52b6ad1..97a78644cb 100644
--- a/lib/stripe.js
+++ b/lib/stripe.js
@@ -287,13 +287,17 @@ Stripe.prototype = {
       throw new Error('AppInfo.name is required');
     }
     info = info || {};
-    this._appInfo = APP_INFO_PROPERTIES.reduce((accum, prop) => {
-      if (typeof info[prop] == 'string') {
-        accum = accum || {};
-        accum[prop] = info[prop];
-      }
-      return accum;
-    }, undefined);
+    this._appInfo = APP_INFO_PROPERTIES.reduce(
+      (accum, prop) => {
+        if (typeof info[prop] == 'string') {
+          accum = accum || {};
+          accum[prop] = info[prop];
+        }
+        return accum;
+      },
+      // @ts-ignore
+      undefined
+    );
   },
   /**
    * @deprecated will be removed in a future major version. Use the config object instead:
diff --git a/lib/utils.js b/lib/utils.js
index 2ed6fb43cf..5031266832 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -9,6 +9,7 @@ let exec = null;
 try {
   exec = require('child_process').exec;
 } catch (e) {
+  // @ts-ignore
   if (e.code !== 'MODULE_NOT_FOUND') {
     throw e;
   }
@@ -77,6 +78,7 @@ const utils = {
       const cleanString = str.replace(/["\n\r\u2028\u2029]/g, ($0) => rc[$0]);
       return (outputs) => {
         return cleanString.replace(/\{([\s\S]+?)\}/g, ($0, $1) =>
+          // @ts-ignore
           encodeURIComponent(outputs[$1] || '')
         );
       };
diff --git a/src/StripeResource.ts b/src/StripeResource.ts
index 9f89af8fab..b4392c0d57 100644
--- a/src/StripeResource.ts
+++ b/src/StripeResource.ts
@@ -12,6 +12,16 @@ const {
 
 const {HttpClient} = require('./net/HttpClient');
 
+// Provide extension mechanism for Stripe Resource Sub-Classes
+StripeResource.extend = utils.protoExtend;
+
+// Expose method-creator & prepared (basic) methods
+StripeResource.method = require('./StripeMethod');
+StripeResource.BASIC_METHODS = require('./StripeMethod.basic');
+
+StripeResource.MAX_BUFFERED_REQUEST_METRICS = 100;
+const MAX_RETRY_AFTER_WAIT = 60;
+
 /**
  * Encapsulates request logic for a Stripe Resource
  */
@@ -35,18 +45,16 @@ function StripeResource(
   this.resourcePath = this.path;
   // @ts-ignore changing type of path
   this.path = utils.makeURLInterpolator(this.path);
-
+  // DEPRECATED: This was kept for backwards compatibility in case users were
+  // using this, but basic methods are now explicitly defined on a resource.
+  if (this.includeBasic) {
+    this.includeBasic.forEach(function(methodName) {
+      // @ts-ignore
+      this[methodName] = StripeResource.BASIC_METHODS[methodName];
+    }, this);
+  }
   this.initialize(...arguments);
 }
-// Provide extension mechanism for Stripe Resource Sub-Classes
-StripeResource.extend = utils.protoExtend;
-
-// Expose method-creator & prepared (basic) methods
-StripeResource.method = require('./StripeMethod');
-StripeResource.BASIC_METHODS = require('./StripeMethod.basic');
-
-StripeResource.MAX_BUFFERED_REQUEST_METRICS = 100;
-const MAX_RETRY_AFTER_WAIT = 60;
 
 StripeResource.prototype = {
   _stripe: null as StripeObject | null,
diff --git a/src/Types.d.ts b/src/Types.d.ts
index b7de25d967..bb2bd48391 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -35,6 +35,7 @@ type StripeResourceObject = {
   basePath: UrlInterpolator;
   path: UrlInterpolator;
   resourcePath: string;
+  includeBasic: Array<string>;
   createResourcePathWithSymbols: (path: string | null | undefined) => string;
   createFullPath: (
     interpolator: UrlInterpolator,
diff --git a/tsconfig.json b/tsconfig.json
index 1b672e1407..b0e175f4d9 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -8,7 +8,7 @@
     "alwaysStrict": true,
     "noImplicitAny": true,
     "noImplicitThis": true,
-    "strict": true
+    "strict": true,
   },
   "include": ["./src/**/*"]
 }

From 3f0eed52c5f7b918afdb865bd635edd80a955596 Mon Sep 17 00:00:00 2001
From: Pavel Krymets <pakrym@stripe.com>
Date: Thu, 10 Nov 2022 07:47:32 -0800
Subject: [PATCH 14/14] sort types

---
 src/Types.d.ts | 282 ++++++++++++++++++++++---------------------------
 1 file changed, 129 insertions(+), 153 deletions(-)

diff --git a/src/Types.d.ts b/src/Types.d.ts
index bb2bd48391..c785e6f3d0 100644
--- a/src/Types.d.ts
+++ b/src/Types.d.ts
@@ -1,64 +1,38 @@
 /* eslint-disable camelcase */
-type StripeObject = {
-  on: any;
-  off: any;
-  once: any;
-  VERSION: string;
-  StripeResource: typeof StripeResource;
-  errors: any;
-  webhooks: any;
-  getApiField: <T = string>(name: string) => T;
-  _prepResources: () => void;
-  _setAppInfo: (appInfo: AppInfo) => void;
-  _setApiKey: (apiKey: string) => void;
-  _prevRequestMetrics: number[];
-  _api: {
-    auth: string | null;
-    host: string;
-    port: string | number;
-    protocol: string;
-    basePath: string;
-    version: string;
-    timeout: string;
-    maxNetworkRetries: number;
-    agent: string;
-    httpClient: any;
-    dev: boolean;
-    stripeAccount: string | null;
-  };
-  _emitter: import('events').EventEmitter;
-  _enableTelemetry: boolean;
-  _getPropsFromConfig: (config: Record<string, unknown>) => UserProvidedConfig;
-};
-type StripeResourceObject = {
-  _stripe: StripeObject;
-  basePath: UrlInterpolator;
-  path: UrlInterpolator;
-  resourcePath: string;
-  includeBasic: Array<string>;
-  createResourcePathWithSymbols: (path: string | null | undefined) => string;
-  createFullPath: (
-    interpolator: UrlInterpolator,
-    urlData: RequestData
-  ) => string;
-  _request: (
-    method: string,
-    host: string,
-    path: string,
-    data: RequestData,
-    auth: string,
-    options: RequestOptions,
-    callback: RequestCallback
-  ) => void;
-  initialize: (...args: Array<any>) => void;
+type AppInfo = {name?: string} & Record<string, unknown>;
+type BufferedFile = {name: string; type: string; file: {data: Buffer}};
+type HttpClientResponseError = {code: number};
+type HttpHeaderValue = string | number | string[];
+type MethodSpec = {
+  method: string;
+  methodType: string;
+  urlParams: Array<string>;
+  path?: string;
+  fullPath?: string;
+  encode: (data: RequestData) => RequestData;
+  validator: (data: RequestData, headers: RequestHeaders) => void;
+  headers: Record<string, string>;
+  streaming?: boolean;
+  host?: string;
+  transformResponseData?: (response: HttpClientResponseInterface) => any;
 };
-type RequestCallbackReturn = any;
+type MultipartRequestData = RequestData | StreamingFile | BufferedFile;
+type RawErrorType =
+  | 'card_error'
+  | 'invalid_request_error'
+  | 'api_error'
+  | 'idempotency_error'
+  | 'rate_limit_error'
+  | 'authentication_error'
+  | 'invalid_grant';
+type RequestArgs = Array<any>;
 type RequestCallback = (
   this: StripeResourceObject | void,
   error: Error | null,
   response?: any
 ) => RequestCallbackReturn;
-
+type RequestCallbackReturn = any;
+type RequestData = Record<string, unknown>;
 type RequestEvent = {
   api_version?: string;
   account?: string;
@@ -67,7 +41,24 @@ type RequestEvent = {
   path?: string;
   request_start_time: number;
 };
-
+type RequestHeaders = Record<string, string | number | string[]>;
+type RequestOptions = {
+  settings?: RequestSettings;
+  streaming?: boolean;
+  headers?: RequestHeaders;
+};
+type RequestOpts = {
+  requestMethod: string;
+  requestPath: string;
+  bodyData: RequestData;
+  queryData: RequestData;
+  auth: string;
+  headers: RequestHeaders;
+  host: string;
+  streaming: boolean;
+  settings: RequestSettings;
+};
+type RequestSettings = {timeout?: number; maxNetworkRetries?: number};
 type ResponseEvent = {
   api_version?: string;
   account?: string;
@@ -80,82 +71,24 @@ type ResponseEvent = {
   request_start_time?: number;
   request_end_time?: number;
 };
-type RequestOptions = {
-  settings?: RequestSettings;
-  streaming?: boolean;
-  headers?: RequestHeaders;
-};
-type RequestSettings = {
-  timeout?: number;
-  maxNetworkRetries?: number;
-};
-type UserProvidedConfig = {
-  apiVersion?: string;
-  protocol?: string;
-  host?: string;
-  httpAgent?: any;
-  timeout?: number;
-  port?: number;
-  maxNetworkRetries?: number;
-  httpClient?: HttpClientInterface;
-  stripeAccount?: string;
-  typescript?: boolean;
-  telemetry?: boolean;
-  appInfo?: AppInfo;
-};
-type HttpHeaderValue = string | number | string[];
-type RequestHeaders = Record<string, string | number | string[]>;
-type RequestData = Record<string, unknown>;
-type MultipartRequestData = RequestData | StreamingFile | BufferedFile;
-
-type BufferedFile = {
-  name: string;
-  type: string;
-  file: {
-    data: Buffer;
-  };
-};
-
+type ResponseHeaderValue = string | string[];
+type ResponseHeaders = Record<string, ResponseHeaderValue>;
+interface HttpClientResponseInterface {
+  getStatusCode: () => number;
+  getHeaders: () => ResponseHeaders;
+  getRawResponse: () => unknown;
+  toStream: (streamCompleteCallback: () => void) => unknown;
+  toJSON: () => Promise<any>;
+}
 type StreamingFile = {
   name: string;
   type: string;
-  file: {
-    data: import('events').EventEmitter;
-  };
-};
-type RequestArgs = Array<any>;
-type UrlInterpolator = (params: Record<string, unknown>) => string;
-type AppInfo = {
-  name?: string;
-} & Record<string, unknown>;
-type StripeResourceNamespaceObject = Record<
-  string,
-  StripeResourceObject | unknown
->;
-type MethodSpec = {
-  method: string;
-  methodType: string;
-  urlParams: Array<string>;
-  path?: string;
-  fullPath?: string;
-  encode: (data: RequestData) => RequestData;
-  validator: (data: RequestData, headers: RequestHeaders) => void;
-  headers: Record<string, string>;
-  streaming?: boolean;
-  host?: string;
-  transformResponseData?: (response: HttpClientResponseInterface) => any;
+  file: {data: import('events').EventEmitter};
 };
-type RequestOpts = {
-  requestMethod: string;
-  requestPath: string;
-  bodyData: RequestData;
-  queryData: RequestData;
-  auth: string;
-  headers: RequestHeaders;
-  host: string;
-  streaming: boolean;
-  settings: RequestSettings;
+type StripeConstructor = {
+  new (key: string, config: Record<string, unknown>): StripeObject;
 };
+declare const Stripe: StripeConstructor;
 type StripeCryptoProvider = {
   computeHMACSignature: (data: string, secret: string) => string;
   computeHMACSignatureAsync: (data: string, secret: string) => Promise<string>;
@@ -173,31 +106,40 @@ interface HttpClientInterface {
     timeout: number
   ) => Promise<HttpClientResponseInterface>;
 }
-type HttpClientResponseError = {
-  code: number;
+type StripeObject = {
+  on: any;
+  off: any;
+  once: any;
+  VERSION: string;
+  StripeResource: typeof StripeResource;
+  errors: any;
+  webhooks: any;
+  getApiField: <T = string>(name: string) => T;
+  _prepResources: () => void;
+  _setAppInfo: (appInfo: AppInfo) => void;
+  _setApiKey: (apiKey: string) => void;
+  _prevRequestMetrics: number[];
+  _api: {
+    auth: string | null;
+    host: string;
+    port: string | number;
+    protocol: string;
+    basePath: string;
+    version: string;
+    timeout: string;
+    maxNetworkRetries: number;
+    agent: string;
+    httpClient: any;
+    dev: boolean;
+    stripeAccount: string | null;
+  };
+  _emitter: import('events').EventEmitter;
+  _enableTelemetry: boolean;
+  _getPropsFromConfig: (config: Record<string, unknown>) => UserProvidedConfig;
 };
-type ResponseHeaderValue = string | string[];
-type ResponseHeaders = Record<string, ResponseHeaderValue>;
-interface HttpClientResponseInterface {
-  getStatusCode: () => number;
-  getHeaders: () => ResponseHeaders;
-  getRawResponse: () => unknown;
-  toStream: (streamCompleteCallback: () => void) => unknown;
-  toJSON: () => Promise<any>;
-}
-type RawErrorType =
-  | 'card_error'
-  | 'invalid_request_error'
-  | 'api_error'
-  | 'idempotency_error'
-  | 'rate_limit_error'
-  | 'authentication_error'
-  | 'invalid_grant';
-
 type StripeRawError = {
   message?: string;
   type?: RawErrorType;
-
   headers?: {[header: string]: string};
   statusCode?: number;
   requestId?: string;
@@ -208,20 +150,54 @@ type StripeRawError = {
   detail?: string;
   charge?: string;
   payment_method_type?: string;
-
   payment_intent?: any;
   payment_method?: any;
   setup_intent?: any;
   source?: any;
   exception?: any;
 };
-
 type StripeResourceConstructor = {
   new (stripe: StripeObject, deprecatedUrlData?: never): StripeResourceObject;
 };
 declare const StripeResource: StripeResourceConstructor;
-
-type StripeConstructor = {
-  new (key: string, config: Record<string, unknown>): StripeObject;
+type StripeResourceNamespaceObject = Record<
+  string,
+  StripeResourceObject | unknown
+>;
+type StripeResourceObject = {
+  _stripe: StripeObject;
+  basePath: UrlInterpolator;
+  path: UrlInterpolator;
+  resourcePath: string;
+  includeBasic: Array<string>;
+  createResourcePathWithSymbols: (path: string | null | undefined) => string;
+  createFullPath: (
+    interpolator: UrlInterpolator,
+    urlData: RequestData
+  ) => string;
+  _request: (
+    method: string,
+    host: string,
+    path: string,
+    data: RequestData,
+    auth: string,
+    options: RequestOptions,
+    callback: RequestCallback
+  ) => void;
+  initialize: (...args: Array<any>) => void;
+};
+type UrlInterpolator = (params: Record<string, unknown>) => string;
+type UserProvidedConfig = {
+  apiVersion?: string;
+  protocol?: string;
+  host?: string;
+  httpAgent?: any;
+  timeout?: number;
+  port?: number;
+  maxNetworkRetries?: number;
+  httpClient?: HttpClientInterface;
+  stripeAccount?: string;
+  typescript?: boolean;
+  telemetry?: boolean;
+  appInfo?: AppInfo;
 };
-declare const Stripe: StripeConstructor;