docs: added JS doc comments and tsconfig

espree.js

@@ -63,6 +63,13 @@ import espreeVersion from "./lib/version.js";
 import * as visitorKeys from "eslint-visitor-keys";
 import { getLatestEcmaVersion, getSupportedEcmaVersions } from "./lib/options.js";
 
+/**
+ * @typedef {import("acorn")} acorn
+ * @typedef {import("./lib/options").ParserOptions} ParserOptions
+ * @typedef {import("./lib/token-translator").EsprimaToken} EsprimaToken
+ * @typedef {import("./lib/token-translator").TokenRange} TokenRange
+ */
+
 
 // To initialize lazily.
 const parsers = {
@@ -101,8 +108,8 @@ const parsers = {
 /**
  * Tokenizes the given code.
  * @param {string} code The code to tokenize.
- * @param {Object} options Options defining how to tokenize.
- * @returns {Token[]} An array of tokens.
+ * @param {ParserOptions} [options] Options defining how to tokenize.
+ * @returns {EsprimaToken[]} An array of tokens.
  * @throws {SyntaxError} If the input code is invalid.
  * @private
  */
@@ -124,8 +131,8 @@ export function tokenize(code, options) {
 /**
  * Parses the given code.
  * @param {string} code The code to tokenize.
- * @param {Object} options Options defining how to tokenize.
- * @returns {ASTNode} The "Program" AST node.
+ * @param {ParserOptions} options Options defining how to tokenize.
+ * @returns {acorn.Node} The "Program" AST node.
  * @throws {SyntaxError} If the input code is invalid.
  */
 export function parse(code, options) {

lib/espree.js

@@ -3,9 +3,24 @@ import TokenTranslator from "./token-translator.js";
 import { normalizeOptions } from "./options.js";
 
 
+/**
+ * @typedef {import("acorn")} acorn
+ * @typedef {import("./token-translator").Range} Range
+ */
+
 const STATE = Symbol("espree's internal state");
 const ESPRIMA_FINISH_NODE = Symbol("espree's esprimaFinishNode");
 
+/**
+ * @typedef {Object} EsprimaComment
+ * @property {"Block"|"Line"} type Type of the comment, can either be "Block" (multiline) or "Line" (single line).
+ * @property {string} text Contents of the comment.
+ * @property {number|undefined} start Start column of a comment.
+ * @property {number|undefined} end End column of the comment.
+ * @property {Range|undefined} range The [start, end] range of a comment.
+ * @property {acorn.Position} startLoc Start location of the comment.
+ * @property {acorn.Position} endLoc End location of the comment.
+ */
 
 /**
  * Converts an Acorn comment to a Esprima comment.
@@ -15,7 +30,7 @@ const ESPRIMA_FINISH_NODE = Symbol("espree's esprimaFinishNode");
  * @param {int} end The index at which the comment ends.
  * @param {Location} startLoc The location at which the comment starts.
  * @param {Location} endLoc The location at which the comment ends.
- * @returns {Object} The comment object.
+ * @returns {EsprimaComment} The comment object.
  * @private
  */
 function convertAcornCommentToEsprimaComment(block, text, start, end, startLoc, endLoc) {
@@ -40,7 +55,12 @@ function convertAcornCommentToEsprimaComment(block, text, start, end, startLoc,
     return comment;
 }
 
-export default () => Parser => {
+/**
+ * Takes an acorn Parser class and returns a new Parser extending from it.
+ * @param {typeof acorn.Parser} Parser A base acorn parser class.
+ * @returns {typeof acorn.Parser} An espree parser extending the base acorn parser.
+ */
+function extendAcornParser(Parser) {
     const tokTypes = Object.assign({}, Parser.acorn.tokTypes);
 
     if (Parser.acornJsx) {
@@ -232,7 +252,7 @@ export default () => Parser => {
 
         /**
          * Overwrites the default raise method to throw Esprima-style errors.
-         * @param {int} pos The position of the error.
+         * @param {number} pos The position of the error.
          * @param {string} message The error message.
          * @throws {SyntaxError} A syntax error.
          * @returns {void}
@@ -249,7 +269,7 @@ export default () => Parser => {
 
         /**
          * Overwrites the default raise method to throw Esprima-style errors.
-         * @param {int} pos The position of the error.
+         * @param {number} pos The position of the error.
          * @param {string} message The error message.
          * @throws {SyntaxError} A syntax error.
          * @returns {void}
@@ -260,7 +280,7 @@ export default () => Parser => {
 
         /**
          * Overwrites the default unexpected method to throw Esprima-style errors.
-         * @param {int} pos The position of the error.
+         * @param {number} pos The position of the error.
          * @throws {SyntaxError} A syntax error.
          * @returns {void}
          */
@@ -305,8 +325,8 @@ export default () => Parser => {
 
         /**
          * Performs last-minute Esprima-specific compatibility checks and fixes.
-         * @param {ASTNode} result The node to check.
-         * @returns {ASTNode} The finished node.
+         * @param {acorn.Node} result The node to check.
+         * @returns {acorn.Node} The finished node.
          */
         [ESPRIMA_FINISH_NODE](result) {
 
@@ -325,4 +345,7 @@ export default () => Parser => {
             return result;
         }
     };
-};
+
+}
+
+export default () => extendAcornParser;

lib/features.js

@@ -14,6 +14,16 @@
 // Public
 //------------------------------------------------------------------------------
 
+/**
+ * @typedef {Object} EcmaFeatures
+ * @property {boolean} [jsx]
+ * @property {boolean} [globalReturn]
+ * @property {boolean} [impliedStrict]
+ */
+
+/**
+ * @type {EcmaFeatures}
+ */
 export default {
 
     // React JSX parsing

lib/options.js

@@ -81,9 +81,25 @@ function normalizeSourceType(sourceType = "script") {
     throw new Error("Invalid sourceType.");
 }
 
+/**
+ * @typedef {import("./features").EcmaFeatures} EcmaFeatures
+ */
+
+/**
+ * @typedef {Object} ParserOptions
+ * @property {boolean} [range] Whether to include the range information for each node.
+ * @property {boolean} [loc] Whether to include the location information for every node.
+ * @property {boolean} [comment] Whether to include an array of all comments
+ * @property {boolean} [tokens] Whether to include an array of all tokens
+ * @property {number|"latest"} [ecmaVersion] The ECMAScript version to use (between 3 and 13, or 2015 and 2022, or "latest").
+ * @property {boolean} [allowReserved] Only allowed when `ecmaVersion` is set to 3.
+ * @property {"script"|"module"|"commonjs"} [sourceType] The kind of the source string being parsed.
+ * @property {EcmaFeatures} [ecmaFeatures] The additional features to enable.
+ */
+
 /**
  * Normalize parserOptions
- * @param {Object} options the parser options to normalize
+ * @param {ParserOptions} options the parser options to normalize
  * @throws {Error} throw an error if found invalid option.
  * @returns {Object} normalized options
  */

lib/token-translator.js

@@ -14,6 +14,29 @@
 // Private
 //------------------------------------------------------------------------------
 
+/**
+ * @typedef {import("acorn")} acorn
+ */
+
+/**
+ * @typedef {Object} Location
+ * @property {acorn.Position} start The start position.
+ * @property {acorn.Position} end The end position.
+ */
+
+/**
+ * @typedef {[number, number]} Range
+ */
+
+/**
+ * @typedef {Object} EsprimaToken
+ * @property {string} type The type of this token.
+ * @property {string} value The string content of the token.
+ * @property {Location|undefined} loc Location in source text.
+ * @property {number|undefined} start start column.
+ * @property {number|undefined} end end column.
+ * @property {Range|undefined} range [start, end] range
+ */
 
 // Esprima Token Types
 const Token = {
@@ -34,7 +57,7 @@ const Token = {
 
 /**
  * Converts part of a template into an Esprima token.
- * @param {AcornToken[]} tokens The Acorn tokens representing the template.
+ * @param {acorn.Token[]} tokens The Acorn tokens representing the template.
  * @param {string} code The source code.
  * @returns {EsprimaToken} The Esprima equivalent of the template token.
  * @private
@@ -94,7 +117,7 @@ TokenTranslator.prototype = {
      * Translates a single Esprima token to a single Acorn token. This may be
      * inaccurate due to how templates are handled differently in Esprima and
      * Acorn, but should be accurate for all other tokens.
-     * @param {AcornToken} token The Acorn token to translate.
+     * @param {acorn.Token} token The Acorn token to translate.
      * @param {Object} extra Espree extra object.
      * @returns {EsprimaToken} The Esprima version of the token.
      */
@@ -174,7 +197,7 @@ TokenTranslator.prototype = {
 
     /**
      * Function to call during Acorn's onToken handler.
-     * @param {AcornToken} token The Acorn token.
+     * @param {acorn.Token} token The Acorn token.
      * @param {Object} extra The Espree extra object.
      * @returns {void}
      */

package.json

@@ -20,8 +20,10 @@
   "files": [
     "lib",
     "dist/espree.cjs",
+    "dist/espree.d.ts",
     "espree.js"
   ],
+  "types": "dist/espree.d.ts",
   "engines": {
     "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
   },
@@ -52,7 +54,9 @@
     "mocha": "^8.3.1",
     "npm-run-all": "^4.1.5",
     "rollup": "^2.41.2",
-    "shelljs": "^0.3.0"
+    "shelljs": "^0.3.0",
+    "typescript": "^4.5.4",
+    "unicode-6.3.0": "^0.7.5"
   },
   "keywords": [
     "ast",
@@ -69,7 +73,7 @@
     "test": "npm-run-all -p unit lint",
     "lint": "eslint \"*.?(c)js\" lib/ tests/lib/",
     "fixlint": "npm run lint -- --fix",
-    "build": "rollup -c rollup.config.js",
+    "build": "rollup -c rollup.config.js && tsc --build",
     "update-version": "node tools/update-version.js",
     "pretest": "npm run build",
     "prepublishOnly": "npm run update-version && npm run build",

tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "include": ["lib/**/*", "espree.js"],
+  "compilerOptions": {
+    "allowJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "outDir": "dist",
+    "declarationMap": true,
+    "strict": true
+  }
+}