metro bundler using mock API file if configured to

metro.config.js

@@ -5,15 +5,32 @@
 
 const {getDefaultConfig} = require('metro-config');
 const _ = require('underscore');
+require('dotenv').config();
 
 /* eslint arrow-body-style: 0 */
 module.exports = (() => {
+    const isUsingMockAPI = process.env.USE_MOCK_API === 'true' || process.env.E2E_TESTING === 'true';
+    if (isUsingMockAPI) {
+        // eslint-disable-next-line no-console
+        console.warn('⚠️ Using mock API');
+    }
+
     return getDefaultConfig()
         .then((config) => {
             return {
                 resolver: {
                     assetExts: _.filter(config.resolver.assetExts, ext => ext !== 'svg'),
                     sourceExts: ['jsx', 'js', 'ts', 'tsx', 'json', 'svg'],
+                    resolveRequest: (context, moduleName, platform) => {
+                        const resolution = context.resolveRequest(context, moduleName, platform);
+                        if (isUsingMockAPI && moduleName.includes('/API')) {
+                            return {
+                                ...resolution,
+                                filePath: resolution.filePath.replace(/src\/libs\/API.js/, 'src/libs/E2E/API.mock.js'),
+                            };
+                        }
+                        return resolution;
+                    },
                 },
                 transformer: {
                     getTransformOptions: () => ({

package.json

@@ -69,7 +69,6 @@
     "babel-polyfill": "^6.26.0",
     "dom-serializer": "^0.2.2",
     "domhandler": "^4.3.0",
-    "dotenv": "^8.2.0",
     "expensify-common": "git+https://github.com/Expensify/expensify-common.git#e67235baa887dcbe9dc4bf41ddf1925f19a1e8ad",
     "fbjs": "^3.0.2",
     "file-loader": "^6.0.0",
@@ -162,6 +161,7 @@
     "copy-webpack-plugin": "^6.4.1",
     "css-loader": "^5.2.4",
     "diff-so-fancy": "^1.3.0",
+    "dotenv": "^16.0.3",
     "electron": "^21.2.2",
     "electron-builder": "23.5.0",
     "electron-notarize": "^1.2.1",

src/libs/API/API.js → src/libs/API.js

@@ -1,9 +1,9 @@
 import _ from 'underscore';
 import Onyx from 'react-native-onyx';
-import * as Request from '../Request';
-import * as SequentialQueue from '../Network/SequentialQueue';
-import pkg from '../../../package.json';
-import CONST from '../../CONST';
+import * as Request from './Request';
+import * as SequentialQueue from './Network/SequentialQueue';
+import pkg from '../../package.json';
+import CONST from '../CONST';
 
 /**
  * All calls to API.write() will be persisted to disk as JSON with the params, successData, and failureData.