From 88fec3d1cca79634e47cd78d5fd2714fdb8c7cb7 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Sat, 7 Oct 2017 21:48:42 +0200
Subject: [PATCH] Add `module.loaded`, and `module.require` should not be
 enumerable (#4623)

* Make `module.require` non-enumerable

* Add `module.loaded`

* Tighten type definition of `Module`
---
 .../__tests__/runtime_require_module.test.js  | 34 +++++++++++++++++--
 .../src/__tests__/test_root/RegularModule.js  |  3 ++
 packages/jest-runtime/src/index.js            | 20 ++++++++---
 3 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/packages/jest-runtime/src/__tests__/runtime_require_module.test.js b/packages/jest-runtime/src/__tests__/runtime_require_module.test.js
index c88f0668c930..0bc393f34320 100644
--- a/packages/jest-runtime/src/__tests__/runtime_require_module.test.js
+++ b/packages/jest-runtime/src/__tests__/runtime_require_module.test.js
@@ -27,6 +27,23 @@ describe('Runtime requireModule', () => {
       expect(exports.isRealModule).toBe(true);
     }));
 
+  it('provides `module` to modules', () =>
+    createRuntime(__filename).then(runtime => {
+      const exports = runtime.requireModule(
+        runtime.__mockRootPath,
+        'RegularModule',
+      );
+      expect(Object.keys(exports.module)).toEqual([
+        'children',
+        'exports',
+        'filename',
+        'id',
+        'loaded',
+        'parent',
+        'paths',
+      ]);
+    }));
+
   it('provides `module.parent` to modules', () =>
     createRuntime(__filename).then(runtime => {
       const exports = runtime.requireModule(
@@ -34,13 +51,13 @@ describe('Runtime requireModule', () => {
         'RequireRegularModule',
       );
       expect(Object.keys(exports.parent)).toEqual([
+        'children',
         'exports',
         'filename',
         'id',
-        'children',
+        'loaded',
         'parent',
         'paths',
-        'require',
       ]);
     }));
 
@@ -74,6 +91,19 @@ describe('Runtime requireModule', () => {
       );
     }));
 
+  it('provides `module.loaded` to modules', () =>
+    createRuntime(__filename).then(runtime => {
+      const exports = runtime.requireModule(
+        runtime.__mockRootPath,
+        'RegularModule',
+      );
+
+      // `exports.loaded` is set while the module is loaded, so should be `false`
+      expect(exports.loaded).toEqual(false);
+      // After the module is loaded we can query `module.loaded` again, at which point it should be `true`
+      expect(exports.isLoaded()).toEqual(true);
+    }));
+
   it('provides `module.filename` to modules', () =>
     createRuntime(__filename).then(runtime => {
       const exports = runtime.requireModule(
diff --git a/packages/jest-runtime/src/__tests__/test_root/RegularModule.js b/packages/jest-runtime/src/__tests__/test_root/RegularModule.js
index c66118146053..1370098e928a 100644
--- a/packages/jest-runtime/src/__tests__/test_root/RegularModule.js
+++ b/packages/jest-runtime/src/__tests__/test_root/RegularModule.js
@@ -39,3 +39,6 @@ exports.object = {};
 exports.parent = module.parent;
 exports.paths = module.paths;
 exports.setModuleStateValue = setModuleStateValue;
+exports.module = module;
+exports.loaded = module.loaded;
+exports.isLoaded = () => module.loaded;
diff --git a/packages/jest-runtime/src/index.js b/packages/jest-runtime/src/index.js
index 991c0e2f2917..bf40fdf8f3cb 100644
--- a/packages/jest-runtime/src/index.js
+++ b/packages/jest-runtime/src/index.js
@@ -29,13 +29,14 @@ import {run as cilRun} from './cli';
 import {options as cliOptions} from './cli/args';
 
 type Module = {|
-  children?: Array<any>,
+  children: Array<Module>,
   exports: any,
   filename: string,
   id: string,
+  loaded: boolean,
   parent?: Module,
   paths?: Array<Path>,
-  require?: Function,
+  require?: (id: string) => any,
 |};
 
 type HasteMapOptions = {|
@@ -311,10 +312,12 @@ class Runtime {
       // We must register the pre-allocated module object first so that any
       // circular dependencies that may arise while evaluating the module can
       // be satisfied.
-      const localModule = {
+      const localModule: Module = {
+        children: [],
         exports: {},
         filename: modulePath,
         id: modulePath,
+        loaded: false,
       };
       moduleRegistry[modulePath] = localModule;
       if (path.extname(modulePath) === '.json') {
@@ -327,6 +330,8 @@ class Runtime {
       } else {
         this._execModule(localModule, options, moduleRegistry, from);
       }
+
+      localModule.loaded = true;
     }
     return moduleRegistry[modulePath].exports;
   }
@@ -381,13 +386,16 @@ class Runtime {
     }
 
     if (manualMock) {
-      const localModule = {
+      const localModule: Module = {
+        children: [],
         exports: {},
         filename: modulePath,
         id: modulePath,
+        loaded: false,
       };
       this._execModule(localModule, undefined, this._mockRegistry, from);
       this._mockRegistry[moduleID] = localModule.exports;
+      localModule.loaded = true;
     } else {
       // Look for a real module to generate an automock from
       this._mockRegistry[moduleID] = this._generateMock(from, moduleName);
@@ -508,7 +516,9 @@ class Runtime {
     );
 
     localModule.paths = this._resolver.getModulePaths(dirname);
-    localModule.require = this._createRequireImplementation(filename, options);
+    Object.defineProperty(localModule, 'require', {
+      value: this._createRequireImplementation(filename, options),
+    });
 
     const transformedFile = this._scriptTransformer.transform(
       filename,