feat: opaque symlink support

packages/jest-haste-map/package.json

@@ -19,6 +19,7 @@
     "jest-util": "^24.9.0",
     "jest-worker": "^24.9.0",
     "micromatch": "^3.1.10",
+    "realpath-native": "^1.0.0",
     "sane": "^4.0.3",
     "walker": "^1.0.7"
   },

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

@@ -5,20 +5,32 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import path from 'path';
 import micromatch from 'micromatch';
+import {sync as realpath} from 'realpath-native';
 import {replacePathSepForGlob} from 'jest-util';
 import {Config} from '@jest/types';
-import {FileData} from './types';
+import {FileData, LinkData} from './types';
 import * as fastPath from './lib/fast_path';
 import H from './constants';
 
 export default class HasteFS {
   private readonly _rootDir: Config.Path;
   private readonly _files: FileData;
+  private readonly _links: LinkData;
 
-  constructor({rootDir, files}: {rootDir: Config.Path; files: FileData}) {
+  constructor({
+    rootDir,
+    files,
+    links,
+  }: {
+    rootDir: Config.Path;
+    files: FileData;
+    links: LinkData;
+  }) {
     this._rootDir = rootDir;
     this._files = files;
+    this._links = links;
   }
 
   getModuleName(file: Config.Path): string | null {
@@ -52,6 +64,20 @@ export default class HasteFS {
     return this._getFileData(file) != null;
   }
 
+  follow(file: Config.Path): Config.Path {
+    const name = fastPath.relative(this._rootDir, file);
+    const link = this._links.get(name);
+    if (!link) {
+      return file;
+    }
+    if (!link[0]) {
+      const target = realpath(file);
+      link[0] = fastPath.relative(this._rootDir, target);
+      return target;
+    }
+    return path.join(this._rootDir, link[0]);
+  }
+
   getAllFiles(): Array<Config.Path> {
     return Array.from(this.getAbsoluteFileIterator());
   }

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

@@ -102,6 +102,7 @@ jest.mock('graceful-fs', () => ({
     error.code = 'ENOENT';
     throw error;
   }),
+  realpath: jest.fn(path => path),
   writeFileSync: jest.fn((path, data, options) => {
     expect(options).toBe(require('v8').serialize ? undefined : 'utf8');
     mockFs[path] = data;
@@ -224,8 +225,6 @@ describe('HasteMap', () => {
 
   it('creates valid cache file paths', () => {
     jest.resetModuleRegistry();
-    HasteMap = require('../');
-
     expect(
       HasteMap.getCacheFilePath('/', '@scoped/package', 'random-value'),
     ).toMatch(/^\/-scoped-package-(.*)$/);
@@ -241,7 +240,6 @@ describe('HasteMap', () => {
 
   it('creates different cache file paths for different dependency extractor cache keys', () => {
     jest.resetModuleRegistry();
-    const HasteMap = require('../');
     const dependencyExtractor = require('./dependencyExtractor');
     const config = {
       ...defaultConfig,
@@ -256,7 +254,6 @@ describe('HasteMap', () => {
 
   it('creates different cache file paths for different hasteImplModulePath cache keys', () => {
     jest.resetModuleRegistry();
-    const HasteMap = require('../');
     const hasteImpl = require('./haste_impl');
     hasteImpl.setCacheKey('foo');
     const hasteMap1 = new HasteMap(defaultConfig);