refactor(jest-support): Replace require.extensions with Module._extensions (#196)

Author: njugray

lib/loader/file_loader.js

@@ -122,7 +122,7 @@ class FileLoader {
   parse() {
     let files = this.options.match;
     if (!files) {
-      files = (process.env.EGG_TYPESCRIPT === 'true' && utils.extensions.includes('.ts'))
+      files = (process.env.EGG_TYPESCRIPT === 'true' && utils.extensions['.ts'])
         ? [ '**/*.(js|ts)', '!**/*.d.ts' ]
         : [ '**/*.js' ];
     } else {

lib/utils/index.js

@@ -5,24 +5,22 @@ const is = require('is-type-of');
 const path = require('path');
 const fs = require('fs');
 const co = require('co');
-const extensions = Object.keys(require.extensions);
-/* istanbul ignore if */
-if (!extensions.length) {
-  // adapt for jest
-  extensions.push('.js', '.node', '.json');
-  if (process.env.EGG_TYPESCRIPT === 'true') {
-    extensions.push('.ts');
-  }
-}
+const BuiltinModule = require('module');
+
+// Guard against poorly mocked module constructors.
+const Module = module.constructor.length > 1
+  ? module.constructor
+  /* istanbul ignore next */
+  : BuiltinModule;
 
 module.exports = {
-  extensions,
+  extensions: Module._extensions,
 
   loadFile(filepath) {
     try {
       // if not js module, just return content buffer
       const extname = path.extname(filepath);
-      if (extname && !extensions.includes(extname)) {
+      if (extname && !Module._extensions[extname]) {
         return fs.readFileSync(filepath);
       }
       // require js module

test/egg-ts.test.js

@@ -11,13 +11,13 @@ describe('test/egg-ts.test.js', () => {
 
   beforeEach(() => {
     require.extensions['.ts'] = require.extensions['.js'];
-    loaderUtil.extensions.push('.ts');
+    loaderUtil.extensions['.ts'] = require.extensions['.js'];
   });
 
   afterEach(() => {
     mm.restore();
-    loaderUtil.extensions.splice(loaderUtil.extensions.indexOf('.ts'), 1);
     delete require.extensions['.ts'];
+    delete loaderUtil.extensions['.ts'];
   });
 
   describe('load ts file', () => {