Simplify and enforce duplicate haste map errors

CHANGELOG.md

@@ -22,6 +22,7 @@
 - `[jest-transform]` Normalize config and remove unecessary checks, convert `TestUtils.js` to TypeScript ([#7801](https://github.com/facebook/jest/pull/7801))
 - `[jest-worker]` Fix `jest-worker` when using pre-allocated jobs ([#7934](https://github.com/facebook/jest/pull/7934))
 - `[jest-changed-files]` Fix `getChangedFilesFromRoots` to not return parts of the commit messages as if they were files, when the commit messages contained multiple paragraphs ([#7961](https://github.com/facebook/jest/pull/7961))
+- `[jest-haste-map]` Enforce uniqueness in names (mocks and haste ids) ([#8002](https://github.com/facebook/jest/pull/8002))
 - `[static]` Remove console log '-' on the front page
 
 ### Chore & Maintenance

packages/jest-haste-map/src/__tests__/__snapshots__/index.test.js.snap

@@ -16,13 +16,7 @@ exports[`HasteMap file system changes processing recovery from duplicate module
 "
 `;
 
-exports[`HasteMap throws on duplicate module ids if "throwOnModuleCollision" is set to true 1`] = `
-[Error: jest-haste-map: Haste module naming collision:
-  Duplicate module name: Strawberry
-  Paths: /project/fruits/another/Strawberry.js collides with /project/fruits/Strawberry.js
-
-This error is caused by \`hasteImpl\` returning the same name for different files.]
-`;
+exports[`HasteMap throws on duplicate module ids if "throwOnModuleCollision" is set to true 1`] = `[Error: Duplicated files or mocks. Please check the console for more info]`;
 
 exports[`HasteMap tries to crawl using node as a fallback 1`] = `
 "jest-haste-map: Watchman crawl failed. Retrying once with node crawler.
@@ -31,23 +25,17 @@ exports[`HasteMap tries to crawl using node as a fallback 1`] = `
 `;
 
 exports[`HasteMap warns on duplicate mock files 1`] = `
-"jest-haste-map: duplicate manual mock found:
-  Module name: subdir/Blueberry
-  Duplicate Mock path: /project/fruits2/__mocks__/subdir/Blueberry.js
-This warning is caused by two manual mock files with the same file name.
-Jest will use the mock file found in: 
-/project/fruits2/__mocks__/subdir/Blueberry.js
- Please delete one of the following two files: 
- /project/fruits1/__mocks__/subdir/Blueberry.js
-/project/fruits2/__mocks__/subdir/Blueberry.js
-
+"jest-haste-map: duplicate manual mock found: subdir/Blueberry
+  The following files share their name; please delete one of them:
+    * <rootDir>/fruits1/__mocks__/subdir/Blueberry.js
+    * <rootDir>/fruits2/__mocks__/subdir/Blueberry.js
 "
 `;
 
 exports[`HasteMap warns on duplicate module ids 1`] = `
-"jest-haste-map: Haste module naming collision:
-  Duplicate module name: Strawberry
-  Paths: /project/fruits/other/Strawberry.js collides with /project/fruits/Strawberry.js
-
-This warning is caused by \`hasteImpl\` returning the same name for different files."
+"jest-haste-map: Haste module naming collision: Strawberry
+  The following files share their name; please adjust your hasteImpl:
+    * <rootDir>/fruits/Strawberry.js
+    * <rootDir>/fruits/other/Strawberry.js
+"
 `;

packages/jest-haste-map/src/__tests__/index.test.js

@@ -128,6 +128,7 @@ const useBuitinsInContext = value => {
 };
 
 let consoleWarn;
+let consoleError;
 let defaultConfig;
 let fs;
 let H;
@@ -180,7 +181,10 @@ describe('HasteMap', () => {
     fs = require('graceful-fs');
 
     consoleWarn = console.warn;
+    consoleError = console.error;
+
     console.warn = jest.fn();
+    console.error = jest.fn();
 
     HasteMap = require('../');
     H = HasteMap.H;
@@ -203,6 +207,7 @@ describe('HasteMap', () => {
 
   afterEach(() => {
     console.warn = consoleWarn;
+    console.error = consoleError;
   });
 
   it('exports constants', () => {
@@ -522,6 +527,8 @@ describe('HasteMap', () => {
   });
 
   it('warns on duplicate mock files', () => {
+    expect.assertions(1);
+
     // Duplicate mock files for blueberry
     mockFs['/project/fruits1/__mocks__/subdir/Blueberry.js'] = `
       // Blueberry
@@ -530,10 +537,14 @@ describe('HasteMap', () => {
       // Blueberry too!
     `;
 
-    return new HasteMap({mocksPattern: '__mocks__', ...defaultConfig})
+    return new HasteMap({
+      mocksPattern: '__mocks__',
+      throwOnModuleCollision: true,
+      ...defaultConfig,
+    })
       .build()
-      .then(({__hasteMapForTest: data}) => {
-        expect(console.warn.mock.calls[0][0]).toMatchSnapshot();
+      .catch(({__hasteMapForTest: data}) => {
+        expect(console.error.mock.calls[0][0]).toMatchSnapshot();
       });
   });
 

packages/jest-haste-map/src/index.ts

@@ -432,27 +432,31 @@ class HasteMap extends EventEmitter {
         H.GENERIC_PLATFORM;
 
       const existingModule = moduleMap[platform];
+
       if (existingModule && existingModule[H.PATH] !== module[H.PATH]) {
-        const message =
-          `jest-haste-map: Haste module naming collision:\n` +
-          `  Duplicate module name: ${id}\n` +
-          `  Paths: ${fastPath.resolve(
-            rootDir,
-            module[H.PATH],
-          )} collides with ` +
-          `${fastPath.resolve(rootDir, existingModule[H.PATH])}\n\nThis ` +
-          `${this._options.throwOnModuleCollision ? 'error' : 'warning'} ` +
-          `is caused by \`hasteImpl\` returning the same name for different` +
-          ` files.`;
+        const method = this._options.throwOnModuleCollision ? 'error' : 'warn';
+
+        this._console[method](
+          [
+            'jest-haste-map: Haste module naming collision: ' + id,
+            '  The following files share their name; please adjust your hasteImpl:',
+            '    * <rootDir>' + path.sep + existingModule[H.PATH],
+            '    * <rootDir>' + path.sep + module[H.PATH],
+            '',
+          ].join('\n'),
+        );
+
         if (this._options.throwOnModuleCollision) {
-          throw new Error(message);
+          throw new DuplicateError(existingModule[H.PATH], module[H.PATH]);
         }
-        this._console.warn(message);
+
         // We do NOT want consumers to use a module that is ambiguous.
         delete moduleMap[platform];
+
         if (Object.keys(moduleMap).length === 1) {
           map.delete(id);
         }
+
         let dupsByPlatform = hasteMap.duplicates.get(id);
         if (dupsByPlatform == null) {
           dupsByPlatform = new Map();
@@ -553,18 +557,26 @@ class HasteMap extends EventEmitter {
     ) {
       const mockPath = getMockName(filePath);
       const existingMockPath = mocks.get(mockPath);
+
       if (existingMockPath) {
-        this._console.warn(
-          `jest-haste-map: duplicate manual mock found:\n` +
-            `  Module name: ${mockPath}\n` +
-            `  Duplicate Mock path: ${filePath}\nThis warning ` +
-            `is caused by two manual mock files with the same file name.\n` +
-            `Jest will use the mock file found in: \n` +
-            `${filePath}\n` +
-            ` Please delete one of the following two files: \n ` +
-            `${path.join(rootDir, existingMockPath)}\n${filePath}\n\n`,
+        const secondMockPath = fastPath.relative(rootDir, filePath);
+        const method = this._options.throwOnModuleCollision ? 'error' : 'warn';
+
+        this._console[method](
+          [
+            'jest-haste-map: duplicate manual mock found: ' + mockPath,
+            '  The following files share their name; please delete one of them:',
+            '    * <rootDir>' + path.sep + existingMockPath,
+            '    * <rootDir>' + path.sep + secondMockPath,
+            '',
+          ].join('\n'),
         );
+
+        if (this._options.throwOnModuleCollision) {
+          throw new DuplicateError(existingMockPath, secondMockPath);
+        }
       }
+
       mocks.set(mockPath, relativeFilePath);
     }
 
@@ -1069,9 +1081,22 @@ class HasteMap extends EventEmitter {
   }
 
   static H: HType;
+  static DuplicateError: typeof DuplicateError;
   static ModuleMap: typeof HasteModuleMap;
 }
 
+class DuplicateError extends Error {
+  mockPath1: string;
+  mockPath2: string;
+
+  constructor(mockPath1: string, mockPath2: string) {
+    super('Duplicated files or mocks. Please check the console for more info');
+
+    this.mockPath1 = mockPath1;
+    this.mockPath2 = mockPath2;
+  }
+}
+
 function copy<T extends Object>(object: T): T {
   return Object.assign(Object.create(null), object);
 }
@@ -1081,6 +1106,7 @@ function copyMap<K, V>(input: Map<K, V>): Map<K, V> {
 }
 
 HasteMap.H = H;
+HasteMap.DuplicateError = DuplicateError;
 HasteMap.ModuleMap = HasteModuleMap;
 
 export = HasteMap;

packages/jest-runtime/src/__tests__/runtime_require_mock.test.js

@@ -8,8 +8,6 @@
 
 'use strict';
 
-const path = require('path');
-
 let createRuntime;
 const consoleWarn = console.warn;
 
@@ -137,29 +135,6 @@ describe('Runtime', () => {
         }).toThrow();
       }));
 
-    it('uses the closest manual mock when duplicates exist', () => {
-      console.warn = jest.fn();
-      return createRuntime(__filename, {
-        rootDir: path.resolve(
-          path.dirname(__filename),
-          'test_root_with_dup_mocks',
-        ),
-      }).then(runtime => {
-        expect(console.warn).toBeCalled();
-        const exports1 = runtime.requireMock(
-          runtime.__mockRootPath,
-          './subdir1/my_module',
-        );
-        expect(exports1.modulePath).toEqual('subdir1/__mocks__/my_module.js');
-
-        const exports2 = runtime.requireMock(
-          runtime.__mockRootPath,
-          './subdir2/my_module',
-        );
-        expect(exports2.modulePath).toEqual('subdir2/__mocks__/my_module.js');
-      });
-    });
-
     it('uses manual mocks when using a custom resolver', () =>
       createRuntime(__filename, {
         // using the default resolver as a custom resolver