✨ Add dotenv file hierarchy (#200)

* ✨ Add dotenv file hierarchy

* ✨ Allow disabling dotenv files

* 🔖 v3.8.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "percy-client",
-  "version": "3.7.0",
+  "version": "3.8.0",
   "description": "JavaScript API client library for Percy (https://percy.io).",
   "main": "dist/main.js",
   "scripts": {

src/dotenv.js

@@ -0,0 +1,22 @@
+const dotenv = require('dotenv');
+
+// mimic dotenv-rails file hierarchy
+// https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use
+export function config() {
+  let {NODE_ENV: env, PERCY_DISABLE_DOTENV: disable} = process.env;
+
+  // don't load dotenv files when disabled
+  if (disable) return;
+
+  let paths = [
+    env && `.env.${env}.local`,
+    // .env.local is not loaded in test environments
+    env === 'test' ? null : '.env.local',
+    env && `.env.${env}`,
+    '.env',
+  ].filter(Boolean);
+
+  for (let path of paths) {
+    dotenv.config({path});
+  }
+}

src/main.js

@@ -9,7 +9,7 @@ const PromisePool = require('es6-promise-pool');
 const regeneratorRuntime = require('regenerator-runtime'); // eslint-disable-line no-unused-vars
 const fs = require('fs');
 
-require('dotenv').config();
+require('./dotenv').config();
 
 const RETRY_ERROR_CODES = ['ECONNRESET', 'ECONNREFUSED', 'EPIPE', 'EHOSTUNREACH', 'EAI_AGAIN'];
 const JSON_API_CONTENT_TYPE = 'application/vnd.api+json';