From ce9e83c01e40ec977f9061c92fa82d82be8633a4 Mon Sep 17 00:00:00 2001
From: Dan Muller <mrmeku@stairwell.com>
Date: Thu, 29 Oct 2020 15:43:00 +0000
Subject: [PATCH 01/13] feat(jest-haste-map): Enable crawling for symlink test
 files

---
 CHANGELOG.md                                  |   1 +
 docs/Configuration.md                         |   2 +
 e2e/__tests__/crawlSymlinks.test.ts           | 114 ++++++++++++++++++
 packages/jest-config/src/ValidConfig.ts       |   1 +
 .../src/__tests__/index.test.js               |  13 ++
 packages/jest-haste-map/src/crawlers/node.ts  |  21 +++-
 packages/jest-haste-map/src/index.ts          |  38 ++++++
 packages/jest-haste-map/src/types.ts          |   1 +
 packages/jest-runtime/src/index.ts            |   1 +
 packages/jest-types/src/Config.ts             |   2 +
 10 files changed, 189 insertions(+), 5 deletions(-)
 create mode 100644 e2e/__tests__/crawlSymlinks.test.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c652a32acd75..31aa3fa9695b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ### Features
 
 - `[jest-core]` Add `findRelatedTests` and `nonFlagArgs` in allowed config options for `updateConfigAndRun` in watch plugins ([#10659](https://github.com/facebook/jest/pull/10659))
+- `[jest-haste-map]` Add `enableSymlinks` configuration option to follow symlinks for test files ([#9350](https://github.com/facebook/jest/issues/9350))
 
 ### Fixes
 
diff --git a/docs/Configuration.md b/docs/Configuration.md
index c34bebedfcdf..b6e304d67d8b 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -476,6 +476,8 @@ type HasteConfig = {
   computeSha1?: boolean;
   // The platform to use as the default, e.g. 'ios'.
   defaultPlatform?: string | null;
+  // Whether to follow symlinks when crawling for files.
+  enableSymlinks?: boolean;
   // Path to a custom implementation of Haste.
   hasteImplModulePath?: string;
   // All platforms to target, e.g ['ios', 'android'].
diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
new file mode 100644
index 000000000000..7a0dfefdc01e
--- /dev/null
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -0,0 +1,114 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+import {tmpdir} from 'os';
+import * as path from 'path';
+
+import runJest from '../runJest';
+import {cleanup, writeFiles, writeSymlinks} from '../Utils';
+
+const DIR = path.resolve(tmpdir(), 'crawl-symlinks-test');
+
+beforeEach(() => {
+  cleanup(DIR);
+});
+
+afterEach(() => {
+  cleanup(DIR);
+});
+
+function init(
+  extraFiles: {
+    [filename: string]: string;
+  } = {},
+) {
+  writeFiles(DIR, {
+    'package.json': JSON.stringify({
+      jest: {
+        testMatch: ['<rootDir>/test-files/test.js'],
+      },
+    }),
+    'symlinked-files/test.js': `
+            test('1+1', () => {
+              expect(1).toBe(1);
+            });
+          `,
+    ...extraFiles,
+  });
+
+  writeSymlinks(DIR, {
+    'symlinked-files/test.js': 'test-files/test.js',
+  });
+}
+
+test('Node crawler picks up symlinked files when option is set as flag', () => {
+  // Symlinks are only enabled on windows with developer mode.
+  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+  if (process.platform === 'win32') {
+    return;
+  }
+
+  init();
+  const {stdout, stderr, exitCode} = runJest(DIR, [
+    '--haste={"enableSymlinks": true}',
+  ]);
+
+  expect(stdout).toEqual('');
+  expect(stderr).toContain('Test Suites: 1 passed, 1 total');
+  expect(exitCode).toEqual(0);
+});
+
+test('Node crawler does not pick up symlinked files by default', () => {
+  init();
+  const {stdout, stderr, exitCode} = runJest(DIR, []);
+  expect(stdout).toContain('No tests found, exiting with code 1');
+  expect(stderr).toEqual('');
+  expect(exitCode).toEqual(1);
+});
+
+test('Warns if --enableSymlinks passed but not set in .watchmanconfig', () => {
+  // Symlinks are only enabled on windows with developer mode.
+  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+  if (process.platform === 'win32') {
+    return;
+  }
+
+  init({'.watchmanconfig': ''});
+
+  const {stdout, stderr, exitCode} = runJest(DIR, [
+    '--haste={"enableSymlinks": true}',
+  ]);
+
+  expect(stdout).toEqual(
+    `jest-haste-map: --enableSymlinks was passed but symlink ` +
+      `crawling is not enabled in .watchmanconfig.
+  To enable symlink crawling in .watchmanconfig set \"watch_symlinks\": true.`,
+  );
+
+  expect(stderr).toContain('Test Suites: 1 passed, 1 total');
+  expect(exitCode).toEqual(0);
+});
+
+test('Warns if watch_symlinks true in .watchmanconfig but not passed', () => {
+  // Symlinks are only enabled on windows with developer mode.
+  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+  if (process.platform === 'win32') {
+    return;
+  }
+
+  init({'.watchmanconfig': JSON.stringify({watch_symlinks: true})});
+
+  const {stdout, stderr, exitCode} = runJest(DIR, []);
+
+  expect(stdout).toContain(
+    'jest-haste-map: watch_symlinks is enabled in .watchmanconfig but ' +
+      '--enableSymlinks was not passed to Jest as a flag.',
+  );
+  expect(stdout).toContain('No tests found, exiting with code 1');
+  expect(stderr).toEqual('');
+
+  expect(exitCode).toEqual(1);
+});
diff --git a/packages/jest-config/src/ValidConfig.ts b/packages/jest-config/src/ValidConfig.ts
index 712f1fb967b5..7d0ba0e6c075 100644
--- a/packages/jest-config/src/ValidConfig.ts
+++ b/packages/jest-config/src/ValidConfig.ts
@@ -54,6 +54,7 @@ const initialOptions: Config.InitialOptions = {
   haste: {
     computeSha1: true,
     defaultPlatform: 'ios',
+    enableSymlinks: false,
     hasteImplModulePath: '<rootDir>/haste_impl.js',
     platforms: ['ios', 'android'],
     throwOnModuleCollision: false,
diff --git a/packages/jest-haste-map/src/__tests__/index.test.js b/packages/jest-haste-map/src/__tests__/index.test.js
index 6dba04a9a81e..2e151abeb5c5 100644
--- a/packages/jest-haste-map/src/__tests__/index.test.js
+++ b/packages/jest-haste-map/src/__tests__/index.test.js
@@ -88,6 +88,19 @@ let mockChangedFiles;
 let mockFs;
 
 jest.mock('graceful-fs', () => ({
+  existsSync: jest.fn(path => {
+    // A file change can be triggered by writing into the
+    // mockChangedFiles object.
+    if (mockChangedFiles && path in mockChangedFiles) {
+      return true;
+    }
+
+    if (mockFs[path]) {
+      return true;
+    }
+
+    return false;
+  }),
   readFileSync: jest.fn((path, options) => {
     // A file change can be triggered by writing into the
     // mockChangedFiles object.
diff --git a/packages/jest-haste-map/src/crawlers/node.ts b/packages/jest-haste-map/src/crawlers/node.ts
index ef04a2762b42..488cc6739378 100644
--- a/packages/jest-haste-map/src/crawlers/node.ts
+++ b/packages/jest-haste-map/src/crawlers/node.ts
@@ -61,6 +61,7 @@ function find(
   extensions: Array<string>,
   ignore: IgnoreMatcher,
   callback: Callback,
+  enableSymlinks?: boolean,
 ): void {
   const result: Result = [];
   let activeCalls = 0;
@@ -98,7 +99,9 @@ function find(
 
         activeCalls++;
 
-        fs.lstat(file, (err, stat) => {
+        const stat = enableSymlinks ? fs.stat : fs.lstat;
+
+        stat(file, (err, stat) => {
           activeCalls--;
 
           // This logic is unnecessary for node > v10.10, but leaving it in
@@ -138,9 +141,15 @@ function findNative(
   extensions: Array<string>,
   ignore: IgnoreMatcher,
   callback: Callback,
+  enableSymlinks: boolean,
 ): void {
   const args = Array.from(roots);
-  args.push('-type', 'f');
+  if (enableSymlinks) {
+    args.push('(', '-type', 'f', '-o', '-type', 'l', ')');
+  } else {
+    args.push('-type', 'f');
+  }
+
   if (extensions.length) {
     args.push('(');
   }
@@ -177,7 +186,8 @@ function findNative(
     } else {
       lines.forEach(path => {
         fs.stat(path, (err, stat) => {
-          if (!err && stat) {
+          // Filter out symlinks that describe directories
+          if (!err && stat && !stat.isDirectory()) {
             result.push([path, stat.mtime.getTime(), stat.size]);
           }
           if (--count === 0) {
@@ -201,6 +211,7 @@ export = async function nodeCrawl(
     forceNodeFilesystemAPI,
     ignore,
     rootDir,
+    enableSymlinks,
     roots,
   } = options;
 
@@ -231,9 +242,9 @@ export = async function nodeCrawl(
     };
 
     if (useNativeFind) {
-      findNative(roots, extensions, ignore, callback);
+      findNative(roots, extensions, ignore, callback, enableSymlinks);
     } else {
-      find(roots, extensions, ignore, callback);
+      find(roots, extensions, ignore, callback, enableSymlinks);
     }
   });
 };
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index c7d82bf36c0a..36e9bb24308f 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -13,6 +13,7 @@ import {EventEmitter} from 'events';
 import {tmpdir} from 'os';
 import * as path from 'path';
 import type {Stats} from 'graceful-fs';
+import {existsSync, readFileSync} from 'graceful-fs';
 import {NodeWatcher, Watcher as SaneWatcher} from 'sane';
 import type {Config} from '@jest/types';
 import {escapePathForRegex} from 'jest-regex-util';
@@ -59,6 +60,7 @@ type Options = {
   computeSha1?: boolean;
   console?: Console;
   dependencyExtractor?: string | null;
+  enableSymlinks?: boolean;
   extensions: Array<string>;
   forceNodeFilesystemAPI?: boolean;
   hasteImplModulePath?: string;
@@ -82,6 +84,7 @@ type InternalOptions = {
   computeDependencies: boolean;
   computeSha1: boolean;
   dependencyExtractor: string | null;
+  enableSymlinks: boolean;
   extensions: Array<string>;
   forceNodeFilesystemAPI: boolean;
   hasteImplModulePath?: string;
@@ -234,6 +237,7 @@ class HasteMap extends EventEmitter {
           : options.computeDependencies,
       computeSha1: options.computeSha1 || false,
       dependencyExtractor: options.dependencyExtractor || null,
+      enableSymlinks: options.enableSymlinks || false,
       extensions: options.extensions,
       forceNodeFilesystemAPI: !!options.forceNodeFilesystemAPI,
       hasteImplModulePath: options.hasteImplModulePath,
@@ -738,6 +742,7 @@ class HasteMap extends EventEmitter {
     const crawlerOptions: CrawlerOptions = {
       computeSha1: options.computeSha1,
       data: hasteMap,
+      enableSymlinks: options.enableSymlinks,
       extensions: options.extensions,
       forceNodeFilesystemAPI: options.forceNodeFilesystemAPI,
       ignore,
@@ -745,6 +750,39 @@ class HasteMap extends EventEmitter {
       roots: options.roots,
     };
 
+    const watchmanConfigPath = path.join(options.rootDir, '.watchmanconfig');
+    if (existsSync(watchmanConfigPath)) {
+      try {
+        const configStr = readFileSync(watchmanConfigPath, 'utf8')
+          .toString()
+          .trim();
+        const watchmanConfig = configStr === '' ? {} : JSON.parse(configStr);
+        const watchSymlinks = Boolean(watchmanConfig['watch_symlinks']);
+
+        // Automatically enable symlink crawling in node crawler if watchman is
+        // set up to crawl symlinks.
+        if (watchSymlinks && !crawlerOptions.enableSymlinks) {
+          this._console.warn(
+            `jest-haste-map: watch_symlinks is enabled in .watchmanconfig ` +
+              `but --enableSymlinks was not passed to Jest as a flag. ` +
+              `  This will result in different behavior when watchman ` +
+              `is enabled or disabled`,
+          );
+        } else if (crawlerOptions.enableSymlinks) {
+          this._console.warn(
+            `jest-haste-map: --enableSymlinks was passed but symlink ` +
+              `crawling is not enabled in .watchmanconfig.\n` +
+              `  To enable symlink crawling in .watchmanconfig set ` +
+              `"watch_symlinks": true.`,
+          );
+        }
+      } catch (error) {
+        this._console.warn(
+          `jest-haste-map: Failed to parse .watchmanconfig.\n  Original Error: ${error}`,
+        );
+      }
+    }
+
     const retry = (error: Error) => {
       if (crawl === watchmanCrawl) {
         this._console.warn(
diff --git a/packages/jest-haste-map/src/types.ts b/packages/jest-haste-map/src/types.ts
index 14a08bac856e..810115513fcc 100644
--- a/packages/jest-haste-map/src/types.ts
+++ b/packages/jest-haste-map/src/types.ts
@@ -30,6 +30,7 @@ export type WorkerMetadata = {
 
 export type CrawlerOptions = {
   computeSha1: boolean;
+  enableSymlinks: boolean;
   data: InternalHasteMap;
   extensions: Array<string>;
   forceNodeFilesystemAPI: boolean;
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index f9c0cb9ac9c4..ff3cdf640312 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -321,6 +321,7 @@ class Runtime {
       computeSha1: config.haste.computeSha1,
       console: options && options.console,
       dependencyExtractor: config.dependencyExtractor,
+      enableSymlinks: config.haste.enableSymlinks,
       extensions: [Snapshot.EXTENSION].concat(config.moduleFileExtensions),
       hasteImplModulePath: config.haste.hasteImplModulePath,
       ignorePattern,
diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
index cf48b24c66d6..fb9e1cbfc4c8 100644
--- a/packages/jest-types/src/Config.ts
+++ b/packages/jest-types/src/Config.ts
@@ -22,6 +22,8 @@ export type HasteConfig = {
   computeSha1?: boolean;
   /** The platform to use as the default, e.g. 'ios'. */
   defaultPlatform?: string | null;
+  /** Whether to follow symlinks when crawling for files. */
+  enableSymlinks?: boolean;
   /** Path to a custom implementation of Haste. */
   hasteImplModulePath?: string;
   /** All platforms to target, e.g ['ios', 'android']. */

From c7d7f6a490a1558910920f1b0e2e8f44fb183324 Mon Sep 17 00:00:00 2001
From: mrmeku <dan@stairwell.com>
Date: Thu, 29 Oct 2020 12:09:02 -0600
Subject: [PATCH 02/13] Update docs/Configuration.md

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 docs/Configuration.md | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/docs/Configuration.md b/docs/Configuration.md
index b6e304d67d8b..f5234bc0b541 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -472,17 +472,17 @@ This will be used to configure the behavior of `jest-haste-map`, Jest's internal
 
 ```ts
 type HasteConfig = {
-  // Whether to hash files using SHA-1.
+  /** Whether to hash files using SHA-1. */
   computeSha1?: boolean;
-  // The platform to use as the default, e.g. 'ios'.
+  /** The platform to use as the default, e.g. 'ios'. */
   defaultPlatform?: string | null;
-  // Whether to follow symlinks when crawling for files.
+  /** Whether to follow symlinks when crawling for files. */
   enableSymlinks?: boolean;
-  // Path to a custom implementation of Haste.
+  /** Path to a custom implementation of Haste. */
   hasteImplModulePath?: string;
-  // All platforms to target, e.g ['ios', 'android'].
+  /** All platforms to target, e.g ['ios', 'android']. */
   platforms?: Array<string>;
-  // Whether to throw on error on module collision.
+  /** Whether to throw on error on module collision. */
   throwOnModuleCollision?: boolean;
 };
 ```

From c87128c1fd6ee6cbf0e7477a8b9b4a007f9a4452 Mon Sep 17 00:00:00 2001
From: mrmeku <dan@stairwell.com>
Date: Fri, 30 Oct 2020 10:03:46 -0600
Subject: [PATCH 03/13] Update packages/jest-haste-map/src/index.ts

Co-authored-by: Simen Bekkhus <sbekkhus91@gmail.com>
---
 packages/jest-haste-map/src/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index 36e9bb24308f..bb7b1276cd46 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -765,7 +765,7 @@ class HasteMap extends EventEmitter {
           this._console.warn(
             `jest-haste-map: watch_symlinks is enabled in .watchmanconfig ` +
               `but --enableSymlinks was not passed to Jest as a flag. ` +
-              `  This will result in different behavior when watchman ` +
+              `This will result in different behavior when watchman ` +
               `is enabled or disabled`,
           );
         } else if (crawlerOptions.enableSymlinks) {

From 766b679b33800303ddd5e7452997e350a5ec03e8 Mon Sep 17 00:00:00 2001
From: Dan Muller <mrmeku@stairwell.com>
Date: Fri, 30 Oct 2020 16:20:16 +0000
Subject: [PATCH 04/13] Add watchman variant of tests

---
 e2e/Utils.ts                         |  16 +++
 e2e/__tests__/crawlSymlinks.test.ts  | 140 +++++++++++++++------------
 packages/jest-haste-map/src/index.ts |   2 +-
 3 files changed, 96 insertions(+), 62 deletions(-)

diff --git a/e2e/Utils.ts b/e2e/Utils.ts
index c8d20585e834..96a4729946d1 100644
--- a/e2e/Utils.ts
+++ b/e2e/Utils.ts
@@ -290,3 +290,19 @@ export const testIfHg = (...args: Parameters<typeof test>) => {
     test.skip(...args);
   }
 };
+
+// Certain environments (like CITGM and GH Actions) do not come with watchman installed
+let watchmanIsInstalled: boolean | null = null;
+
+export const testIfWatchman = (...args: Parameters<typeof test>) => {
+  if (watchmanIsInstalled === null) {
+    watchmanIsInstalled = which.sync('watchman', {nothrow: true}) !== null;
+  }
+
+  if (watchmanIsInstalled) {
+    test(...args);
+  } else {
+    console.warn('watchman is not installed - skipping some tests');
+    test.skip(...args);
+  }
+};
diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
index 7a0dfefdc01e..0802972a0d9b 100644
--- a/e2e/__tests__/crawlSymlinks.test.ts
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -8,7 +8,7 @@ import {tmpdir} from 'os';
 import * as path from 'path';
 
 import runJest from '../runJest';
-import {cleanup, writeFiles, writeSymlinks} from '../Utils';
+import {cleanup, testIfWatchman, writeFiles, writeSymlinks} from '../Utils';
 
 const DIR = path.resolve(tmpdir(), 'crawl-symlinks-test');
 
@@ -44,71 +44,89 @@ function init(
   });
 }
 
-test('Node crawler picks up symlinked files when option is set as flag', () => {
-  // Symlinks are only enabled on windows with developer mode.
-  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-  if (process.platform === 'win32') {
-    return;
-  }
-
-  init();
-  const {stdout, stderr, exitCode} = runJest(DIR, [
-    '--haste={"enableSymlinks": true}',
-  ]);
-
-  expect(stdout).toEqual('');
-  expect(stderr).toContain('Test Suites: 1 passed, 1 total');
-  expect(exitCode).toEqual(0);
-});
-
-test('Node crawler does not pick up symlinked files by default', () => {
-  init();
-  const {stdout, stderr, exitCode} = runJest(DIR, []);
-  expect(stdout).toContain('No tests found, exiting with code 1');
-  expect(stderr).toEqual('');
-  expect(exitCode).toEqual(1);
-});
-
-test('Warns if --enableSymlinks passed but not set in .watchmanconfig', () => {
-  // Symlinks are only enabled on windows with developer mode.
-  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-  if (process.platform === 'win32') {
-    return;
-  }
-
-  init({'.watchmanconfig': ''});
-
-  const {stdout, stderr, exitCode} = runJest(DIR, [
-    '--haste={"enableSymlinks": true}',
-  ]);
-
-  expect(stdout).toEqual(
-    `jest-haste-map: --enableSymlinks was passed but symlink ` +
-      `crawling is not enabled in .watchmanconfig.
+[
+  {runner: test, watchmanFlag: '--no-watchman'},
+  {runner: testIfWatchman, watchmanFlag: '--watchman'},
+].forEach(({watchmanFlag, runner}) => {
+  describe(`crawling symlinks with ${watchmanFlag}`, () => {
+    runner(
+      'Node crawler picks up symlinked files when option is set as flag',
+      () => {
+        // Symlinks are only enabled on windows with developer mode.
+        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+        if (process.platform === 'win32') {
+          return;
+        }
+
+        init();
+        const {stdout, stderr, exitCode} = runJest(DIR, [
+          '--haste={"enableSymlinks": true}',
+          watchmanFlag,
+        ]);
+
+        expect(stdout).toEqual('');
+        expect(stderr).toContain('Test Suites: 1 passed, 1 total');
+        expect(exitCode).toEqual(0);
+      },
+    );
+
+    runner('Node crawler does not pick up symlinked files by default', () => {
+      init();
+      const {stdout, stderr, exitCode} = runJest(DIR, [watchmanFlag]);
+      expect(stdout).toContain('No tests found, exiting with code 1');
+      expect(stderr).toEqual('');
+      expect(exitCode).toEqual(1);
+    });
+
+    runner(
+      'Warns if --enableSymlinks passed but not set in .watchmanconfig',
+      () => {
+        // Symlinks are only enabled on windows with developer mode.
+        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+        if (process.platform === 'win32') {
+          return;
+        }
+
+        init({'.watchmanconfig': ''});
+
+        const {stdout, stderr, exitCode} = runJest(DIR, [
+          '--haste={"enableSymlinks": true}',
+          watchmanFlag,
+        ]);
+
+        expect(stdout).toEqual(
+          `jest-haste-map: --enableSymlinks was passed but symlink ` +
+            `crawling is not enabled in .watchmanconfig.
   To enable symlink crawling in .watchmanconfig set \"watch_symlinks\": true.`,
-  );
+        );
 
-  expect(stderr).toContain('Test Suites: 1 passed, 1 total');
-  expect(exitCode).toEqual(0);
-});
+        expect(stderr).toContain('Test Suites: 1 passed, 1 total');
+        expect(exitCode).toEqual(0);
+      },
+    );
 
-test('Warns if watch_symlinks true in .watchmanconfig but not passed', () => {
-  // Symlinks are only enabled on windows with developer mode.
-  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-  if (process.platform === 'win32') {
-    return;
-  }
+    runner(
+      'Warns if watch_symlinks true in .watchmanconfig but not passed',
+      () => {
+        // Symlinks are only enabled on windows with developer mode.
+        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+        if (process.platform === 'win32') {
+          return;
+        }
 
-  init({'.watchmanconfig': JSON.stringify({watch_symlinks: true})});
+        init({'.watchmanconfig': JSON.stringify({watch_symlinks: true})});
 
-  const {stdout, stderr, exitCode} = runJest(DIR, []);
+        const {stdout, stderr, exitCode} = runJest(DIR, [watchmanFlag]);
 
-  expect(stdout).toContain(
-    'jest-haste-map: watch_symlinks is enabled in .watchmanconfig but ' +
-      '--enableSymlinks was not passed to Jest as a flag.',
-  );
-  expect(stdout).toContain('No tests found, exiting with code 1');
-  expect(stderr).toEqual('');
+        expect(stdout).toContain(
+          'jest-haste-map: watch_symlinks is enabled in .watchmanconfig but ' +
+            '--enableSymlinks was not passed to Jest as a flag.',
+        );
+        expect(stdout).toContain('No tests found, exiting with code 1');
+        expect(stderr).toEqual('');
 
-  expect(exitCode).toEqual(1);
+        expect(exitCode).toEqual(1);
+      },
+    );
+  });
 });
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index bb7b1276cd46..36e9bb24308f 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -765,7 +765,7 @@ class HasteMap extends EventEmitter {
           this._console.warn(
             `jest-haste-map: watch_symlinks is enabled in .watchmanconfig ` +
               `but --enableSymlinks was not passed to Jest as a flag. ` +
-              `This will result in different behavior when watchman ` +
+              `  This will result in different behavior when watchman ` +
               `is enabled or disabled`,
           );
         } else if (crawlerOptions.enableSymlinks) {

From cc360f956a54e14dfeccccbac09c0925fd37af5e Mon Sep 17 00:00:00 2001
From: Daniel Muller <mrmeku@gmail.com>
Date: Fri, 30 Oct 2020 20:59:53 -0600
Subject: [PATCH 05/13] Throw if watchman is used with haste.enableSymlinks

---
 docs/Configuration.md                |   6 +-
 e2e/__tests__/crawlSymlinks.test.ts  | 126 +++++++++------------------
 packages/jest-haste-map/src/index.ts |  42 +++------
 packages/jest-types/src/Config.ts    |   6 +-
 4 files changed, 64 insertions(+), 116 deletions(-)

diff --git a/docs/Configuration.md b/docs/Configuration.md
index f5234bc0b541..af05443ecbec 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -476,7 +476,11 @@ type HasteConfig = {
   computeSha1?: boolean;
   /** The platform to use as the default, e.g. 'ios'. */
   defaultPlatform?: string | null;
-  /** Whether to follow symlinks when crawling for files. */
+  /** 
+   * Whether to follow symlinks when crawling for files.
+   *   This options cannot be used in projects which use watchman.
+   *   Projects with a .watchmanconfig will error if this option is set to true.
+   */
   enableSymlinks?: boolean;
   /** Path to a custom implementation of Haste. */
   hasteImplModulePath?: string;
diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
index 0802972a0d9b..dab330d750ec 100644
--- a/e2e/__tests__/crawlSymlinks.test.ts
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -8,7 +8,7 @@ import {tmpdir} from 'os';
 import * as path from 'path';
 
 import runJest from '../runJest';
-import {cleanup, testIfWatchman, writeFiles, writeSymlinks} from '../Utils';
+import {cleanup, writeFiles, writeSymlinks} from '../Utils';
 
 const DIR = path.resolve(tmpdir(), 'crawl-symlinks-test');
 
@@ -44,89 +44,47 @@ function init(
   });
 }
 
-[
-  {runner: test, watchmanFlag: '--no-watchman'},
-  {runner: testIfWatchman, watchmanFlag: '--watchman'},
-].forEach(({watchmanFlag, runner}) => {
-  describe(`crawling symlinks with ${watchmanFlag}`, () => {
-    runner(
-      'Node crawler picks up symlinked files when option is set as flag',
-      () => {
-        // Symlinks are only enabled on windows with developer mode.
-        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-        if (process.platform === 'win32') {
-          return;
-        }
-
-        init();
-        const {stdout, stderr, exitCode} = runJest(DIR, [
-          '--haste={"enableSymlinks": true}',
-          watchmanFlag,
-        ]);
-
-        expect(stdout).toEqual('');
-        expect(stderr).toContain('Test Suites: 1 passed, 1 total');
-        expect(exitCode).toEqual(0);
-      },
-    );
-
-    runner('Node crawler does not pick up symlinked files by default', () => {
-      init();
-      const {stdout, stderr, exitCode} = runJest(DIR, [watchmanFlag]);
-      expect(stdout).toContain('No tests found, exiting with code 1');
-      expect(stderr).toEqual('');
-      expect(exitCode).toEqual(1);
-    });
-
-    runner(
-      'Warns if --enableSymlinks passed but not set in .watchmanconfig',
-      () => {
-        // Symlinks are only enabled on windows with developer mode.
-        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-        if (process.platform === 'win32') {
-          return;
-        }
-
-        init({'.watchmanconfig': ''});
-
-        const {stdout, stderr, exitCode} = runJest(DIR, [
-          '--haste={"enableSymlinks": true}',
-          watchmanFlag,
-        ]);
-
-        expect(stdout).toEqual(
-          `jest-haste-map: --enableSymlinks was passed but symlink ` +
-            `crawling is not enabled in .watchmanconfig.
-  To enable symlink crawling in .watchmanconfig set \"watch_symlinks\": true.`,
-        );
-
-        expect(stderr).toContain('Test Suites: 1 passed, 1 total');
-        expect(exitCode).toEqual(0);
-      },
-    );
-
-    runner(
-      'Warns if watch_symlinks true in .watchmanconfig but not passed',
-      () => {
-        // Symlinks are only enabled on windows with developer mode.
-        // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
-        if (process.platform === 'win32') {
-          return;
-        }
-
-        init({'.watchmanconfig': JSON.stringify({watch_symlinks: true})});
-
-        const {stdout, stderr, exitCode} = runJest(DIR, [watchmanFlag]);
+const noWatchman = '--no-watchman';
+test('Node crawler picks up symlinked files when option is set as flag', () => {
+  // Symlinks are only enabled on windows with developer mode.
+  // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+  if (process.platform === 'win32') {
+    return;
+  }
+
+  init();
+  const {stdout, stderr, exitCode} = runJest(DIR, [
+    '--haste={"enableSymlinks": true}',
+    noWatchman,
+  ]);
+
+  expect(stdout).toEqual('');
+  expect(stderr).toContain('Test Suites: 1 passed, 1 total');
+  expect(exitCode).toEqual(0);
+});
 
-        expect(stdout).toContain(
-          'jest-haste-map: watch_symlinks is enabled in .watchmanconfig but ' +
-            '--enableSymlinks was not passed to Jest as a flag.',
-        );
-        expect(stdout).toContain('No tests found, exiting with code 1');
-        expect(stderr).toEqual('');
+test('Node crawler does not pick up symlinked files by default', () => {
+  init();
+  const {stdout, stderr, exitCode} = runJest(DIR, [noWatchman]);
+  expect(stdout).toContain('No tests found, exiting with code 1');
+  expect(stderr).toEqual('');
+  expect(exitCode).toEqual(1);
+});
 
-        expect(exitCode).toEqual(1);
-      },
-    );
-  });
+test('Should throw if .watchmanconfig used with haste.enableSymlinks', () => {
+  init({'.watchmanconfig': JSON.stringify({})});
+
+  const {stdout, stderr, exitCode} = runJest(DIR, [
+    '--haste={"enableSymlinks": true}',
+  ]);
+
+  expect(stderr).toEqual('');
+  expect(stdout).toContain(
+    'jest-haste-map: haste.enableSymlinks config option was set, but ' +
+      'is incompatible with watchman.\n' +
+      '  Either set haste.enableSymlinks to false or remove ' +
+      '.watchmanconfig to disable watchman. \n' +
+      '  Exiting with code 1.',
+  );
+  expect(exitCode).toEqual(1);
 });
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index 36e9bb24308f..fba2d9dca9bc 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -13,7 +13,7 @@ import {EventEmitter} from 'events';
 import {tmpdir} from 'os';
 import * as path from 'path';
 import type {Stats} from 'graceful-fs';
-import {existsSync, readFileSync} from 'graceful-fs';
+import {existsSync} from 'graceful-fs';
 import {NodeWatcher, Watcher as SaneWatcher} from 'sane';
 import type {Config} from '@jest/types';
 import {escapePathForRegex} from 'jest-regex-util';
@@ -750,36 +750,18 @@ class HasteMap extends EventEmitter {
       roots: options.roots,
     };
 
-    const watchmanConfigPath = path.join(options.rootDir, '.watchmanconfig');
-    if (existsSync(watchmanConfigPath)) {
-      try {
-        const configStr = readFileSync(watchmanConfigPath, 'utf8')
-          .toString()
-          .trim();
-        const watchmanConfig = configStr === '' ? {} : JSON.parse(configStr);
-        const watchSymlinks = Boolean(watchmanConfig['watch_symlinks']);
-
-        // Automatically enable symlink crawling in node crawler if watchman is
-        // set up to crawl symlinks.
-        if (watchSymlinks && !crawlerOptions.enableSymlinks) {
-          this._console.warn(
-            `jest-haste-map: watch_symlinks is enabled in .watchmanconfig ` +
-              `but --enableSymlinks was not passed to Jest as a flag. ` +
-              `  This will result in different behavior when watchman ` +
-              `is enabled or disabled`,
-          );
-        } else if (crawlerOptions.enableSymlinks) {
-          this._console.warn(
-            `jest-haste-map: --enableSymlinks was passed but symlink ` +
-              `crawling is not enabled in .watchmanconfig.\n` +
-              `  To enable symlink crawling in .watchmanconfig set ` +
-              `"watch_symlinks": true.`,
-          );
-        }
-      } catch (error) {
-        this._console.warn(
-          `jest-haste-map: Failed to parse .watchmanconfig.\n  Original Error: ${error}`,
+    if (options.enableSymlinks) {
+      const watchmanConfigPath = path.join(options.rootDir, '.watchmanconfig');
+
+      if (existsSync(watchmanConfigPath)) {
+        this._console.error(
+          'jest-haste-map: haste.enableSymlinks config option was set, but ' +
+            'is incompatible with watchman.\n' +
+            '  Either set haste.enableSymlinks to false or remove ' +
+            '.watchmanconfig to disable watchman. \n' +
+            '  Exiting with code 1.',
         );
+        process.exit(1);
       }
     }
 
diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
index fb9e1cbfc4c8..206b5868ae70 100644
--- a/packages/jest-types/src/Config.ts
+++ b/packages/jest-types/src/Config.ts
@@ -22,7 +22,11 @@ export type HasteConfig = {
   computeSha1?: boolean;
   /** The platform to use as the default, e.g. 'ios'. */
   defaultPlatform?: string | null;
-  /** Whether to follow symlinks when crawling for files. */
+  /**
+   * Whether to follow symlinks when crawling for files.
+   *   This options cannot be used in projects which use watchman.
+   *   Projects with a .watchmanconfig will error if this option is set to true.
+   */
   enableSymlinks?: boolean;
   /** Path to a custom implementation of Haste. */
   hasteImplModulePath?: string;

From abc5aaa05573901cff17080ed6e68a956a46d5d5 Mon Sep 17 00:00:00 2001
From: Daniel Muller <mrmeku@gmail.com>
Date: Sun, 1 Nov 2020 17:01:29 -0700
Subject: [PATCH 06/13] Move validation logic to jest-config

---
 docs/Configuration.md                 |  2 +-
 e2e/Utils.ts                          | 16 ----------------
 e2e/__tests__/crawlSymlinks.test.ts   | 21 +--------------------
 packages/jest-config/src/normalize.ts |  8 ++++++++
 packages/jest-haste-map/src/index.ts  | 16 ----------------
 5 files changed, 10 insertions(+), 53 deletions(-)

diff --git a/docs/Configuration.md b/docs/Configuration.md
index af05443ecbec..8a0b7cb1df02 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -476,7 +476,7 @@ type HasteConfig = {
   computeSha1?: boolean;
   /** The platform to use as the default, e.g. 'ios'. */
   defaultPlatform?: string | null;
-  /** 
+  /**
    * Whether to follow symlinks when crawling for files.
    *   This options cannot be used in projects which use watchman.
    *   Projects with a .watchmanconfig will error if this option is set to true.
diff --git a/e2e/Utils.ts b/e2e/Utils.ts
index 96a4729946d1..c8d20585e834 100644
--- a/e2e/Utils.ts
+++ b/e2e/Utils.ts
@@ -290,19 +290,3 @@ export const testIfHg = (...args: Parameters<typeof test>) => {
     test.skip(...args);
   }
 };
-
-// Certain environments (like CITGM and GH Actions) do not come with watchman installed
-let watchmanIsInstalled: boolean | null = null;
-
-export const testIfWatchman = (...args: Parameters<typeof test>) => {
-  if (watchmanIsInstalled === null) {
-    watchmanIsInstalled = which.sync('watchman', {nothrow: true}) !== null;
-  }
-
-  if (watchmanIsInstalled) {
-    test(...args);
-  } else {
-    console.warn('watchman is not installed - skipping some tests');
-    test.skip(...args);
-  }
-};
diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
index dab330d750ec..32d2f78068e9 100644
--- a/e2e/__tests__/crawlSymlinks.test.ts
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -6,9 +6,8 @@
  */
 import {tmpdir} from 'os';
 import * as path from 'path';
-
-import runJest from '../runJest';
 import {cleanup, writeFiles, writeSymlinks} from '../Utils';
+import runJest from '../runJest';
 
 const DIR = path.resolve(tmpdir(), 'crawl-symlinks-test');
 
@@ -70,21 +69,3 @@ test('Node crawler does not pick up symlinked files by default', () => {
   expect(stderr).toEqual('');
   expect(exitCode).toEqual(1);
 });
-
-test('Should throw if .watchmanconfig used with haste.enableSymlinks', () => {
-  init({'.watchmanconfig': JSON.stringify({})});
-
-  const {stdout, stderr, exitCode} = runJest(DIR, [
-    '--haste={"enableSymlinks": true}',
-  ]);
-
-  expect(stderr).toEqual('');
-  expect(stdout).toContain(
-    'jest-haste-map: haste.enableSymlinks config option was set, but ' +
-      'is incompatible with watchman.\n' +
-      '  Either set haste.enableSymlinks to false or remove ' +
-      '.watchmanconfig to disable watchman. \n' +
-      '  Exiting with code 1.',
-  );
-  expect(exitCode).toEqual(1);
-});
diff --git a/packages/jest-config/src/normalize.ts b/packages/jest-config/src/normalize.ts
index 82da0cc8a397..8e91123cb089 100644
--- a/packages/jest-config/src/normalize.ts
+++ b/packages/jest-config/src/normalize.ts
@@ -952,6 +952,14 @@ export default function normalize(
     return newOptions;
   }, newOptions);
 
+  if (options.watchman && options.haste?.enableSymlinks) {
+    throw new ValidationError(
+      'Validation Error',
+      'haste.enableSymlinks is incompatible with watchman',
+      'Either set haste.enableSymlinks to false or do not use watchman',
+    );
+  }
+
   newOptions.roots.forEach((root, i) => {
     verifyDirectoryExists(root, `roots[${i}]`);
   });
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index fba2d9dca9bc..cc350d66a2bf 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -13,7 +13,6 @@ import {EventEmitter} from 'events';
 import {tmpdir} from 'os';
 import * as path from 'path';
 import type {Stats} from 'graceful-fs';
-import {existsSync} from 'graceful-fs';
 import {NodeWatcher, Watcher as SaneWatcher} from 'sane';
 import type {Config} from '@jest/types';
 import {escapePathForRegex} from 'jest-regex-util';
@@ -750,21 +749,6 @@ class HasteMap extends EventEmitter {
       roots: options.roots,
     };
 
-    if (options.enableSymlinks) {
-      const watchmanConfigPath = path.join(options.rootDir, '.watchmanconfig');
-
-      if (existsSync(watchmanConfigPath)) {
-        this._console.error(
-          'jest-haste-map: haste.enableSymlinks config option was set, but ' +
-            'is incompatible with watchman.\n' +
-            '  Either set haste.enableSymlinks to false or remove ' +
-            '.watchmanconfig to disable watchman. \n' +
-            '  Exiting with code 1.',
-        );
-        process.exit(1);
-      }
-    }
-
     const retry = (error: Error) => {
       if (crawl === watchmanCrawl) {
         this._console.warn(

From fb2e5268d89db0b0b68245e8c115fe62428bd0f9 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Mon, 2 Nov 2020 08:31:05 +0100
Subject: [PATCH 07/13] error in haste map as well and add tests verifying it

---
 e2e/__tests__/crawlSymlinks.test.ts           | 25 +++++++++++++
 .../src/__tests__/normalize.test.js           | 23 ++++++++++++
 packages/jest-config/src/normalize.ts         |  4 +++
 .../src/__tests__/index.test.js               | 36 +++++++++++++++++++
 packages/jest-haste-map/src/index.ts          |  8 +++++
 5 files changed, 96 insertions(+)

diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
index 32d2f78068e9..8f59213ff0ae 100644
--- a/e2e/__tests__/crawlSymlinks.test.ts
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -6,6 +6,7 @@
  */
 import {tmpdir} from 'os';
 import * as path from 'path';
+import {wrap} from 'jest-snapshot-serializer-raw';
 import {cleanup, writeFiles, writeSymlinks} from '../Utils';
 import runJest from '../runJest';
 
@@ -69,3 +70,27 @@ test('Node crawler does not pick up symlinked files by default', () => {
   expect(stderr).toEqual('');
   expect(exitCode).toEqual(1);
 });
+
+test('Should throw if watchman used with haste.enableSymlinks', () => {
+  init({'.watchmanconfig': JSON.stringify({})});
+
+  // it should throw both if watchman is explicitly provided and not
+  const run1 = runJest(DIR, ['--haste={"enableSymlinks": true}']);
+  const run2 = runJest(DIR, ['--haste={"enableSymlinks": true}', '--watchman']);
+
+  expect(run1.exitCode).toEqual(run2.exitCode);
+  expect(run1.stderr).toEqual(run2.stderr);
+  expect(run1.stdout).toEqual(run2.stdout);
+
+  const {exitCode, stderr, stdout} = run1;
+
+  expect(stdout).toEqual('');
+  expect(wrap(stderr)).toMatchInlineSnapshot(`
+    Validation Error:
+
+    haste.enableSymlinks is incompatible with watchman
+
+    Either set haste.enableSymlinks to false or do not use watchman
+  `);
+  expect(exitCode).toEqual(1);
+});
diff --git a/packages/jest-config/src/__tests__/normalize.test.js b/packages/jest-config/src/__tests__/normalize.test.js
index ae3b198b2fed..6cde82c538e7 100644
--- a/packages/jest-config/src/__tests__/normalize.test.js
+++ b/packages/jest-config/src/__tests__/normalize.test.js
@@ -1714,3 +1714,26 @@ describe('testTimeout', () => {
     ).toThrowErrorMatchingSnapshot();
   });
 });
+
+describe('haste.enableSymlinks', () => {
+  it('should throw if watchman is not disabled', () => {
+    expect(() =>
+      normalize({haste: {enableSymlinks: true}, rootDir: '/root/'}, {}),
+    ).toThrow('haste.enableSymlinks is incompatible with watchman');
+
+    expect(() =>
+      normalize(
+        {haste: {enableSymlinks: true}, rootDir: '/root/', watchman: true},
+        {},
+      ),
+    ).toThrow('haste.enableSymlinks is incompatible with watchman');
+
+    const {options} = normalize(
+      {haste: {enableSymlinks: true}, rootDir: '/root/', watchman: false},
+      {},
+    );
+
+    expect(options.haste.enableSymlinks).toBe(true);
+    expect(options.watchman).toBe(false);
+  });
+});
diff --git a/packages/jest-config/src/normalize.ts b/packages/jest-config/src/normalize.ts
index 8e91123cb089..f9f8d6fe45c7 100644
--- a/packages/jest-config/src/normalize.ts
+++ b/packages/jest-config/src/normalize.ts
@@ -577,6 +577,10 @@ export default function normalize(
     });
   }
 
+  if (options.watchman == null) {
+    options.watchman = DEFAULT_CONFIG.watchman;
+  }
+
   const optionKeys = Object.keys(options) as Array<keyof Config.InitialOptions>;
 
   optionKeys.reduce((newOptions, key: keyof Config.InitialOptions) => {
diff --git a/packages/jest-haste-map/src/__tests__/index.test.js b/packages/jest-haste-map/src/__tests__/index.test.js
index 2e151abeb5c5..b571f3486618 100644
--- a/packages/jest-haste-map/src/__tests__/index.test.js
+++ b/packages/jest-haste-map/src/__tests__/index.test.js
@@ -517,6 +517,42 @@ describe('HasteMap', () => {
     });
   });
 
+  it('throws if both symlinks and watchman is enabled', () => {
+    expect(
+      () => new HasteMap({...defaultConfig, enableSymlinks: true}),
+    ).toThrow(
+      'Set either `enableSymlinks` to false or `useWatchman` to false.',
+    );
+    expect(
+      () =>
+        new HasteMap({
+          ...defaultConfig,
+          enableSymlinks: true,
+          useWatchman: true,
+        }),
+    ).toThrow(
+      'Set either `enableSymlinks` to false or `useWatchman` to false.',
+    );
+
+    expect(
+      () =>
+        new HasteMap({
+          ...defaultConfig,
+          enableSymlinks: false,
+          useWatchman: true,
+        }),
+    ).not.toThrow();
+
+    expect(
+      () =>
+        new HasteMap({
+          ...defaultConfig,
+          enableSymlinks: true,
+          useWatchman: false,
+        }),
+    ).not.toThrow();
+  });
+
   describe('builds a haste map on a fresh cache with SHA-1s', () => {
     [false, true].forEach(useWatchman => {
       it('uses watchman: ' + useWatchman, async () => {
diff --git a/packages/jest-haste-map/src/index.ts b/packages/jest-haste-map/src/index.ts
index cc350d66a2bf..d2c28a6b4102 100644
--- a/packages/jest-haste-map/src/index.ts
+++ b/packages/jest-haste-map/src/index.ts
@@ -278,6 +278,14 @@ class HasteMap extends EventEmitter {
       this._options.ignorePattern = new RegExp(VCS_DIRECTORIES);
     }
 
+    if (this._options.enableSymlinks && this._options.useWatchman) {
+      throw new Error(
+        'jest-haste-map: enableSymlinks config option was set, but ' +
+          'is incompatible with watchman.\n' +
+          'Set either `enableSymlinks` to false or `useWatchman` to false.',
+      );
+    }
+
     const rootDirHash = createHash('md5').update(options.rootDir).digest('hex');
     let hasteImplHash = '';
     let dependencyExtractorHash = '';

From a531e780cbad319366e5c627441a9614bcb03dce Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Mon, 2 Nov 2020 09:00:02 +0100
Subject: [PATCH 08/13] remove optional

---
 packages/jest-haste-map/src/crawlers/node.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/jest-haste-map/src/crawlers/node.ts b/packages/jest-haste-map/src/crawlers/node.ts
index 488cc6739378..d336f8c886e6 100644
--- a/packages/jest-haste-map/src/crawlers/node.ts
+++ b/packages/jest-haste-map/src/crawlers/node.ts
@@ -61,7 +61,7 @@ function find(
   extensions: Array<string>,
   ignore: IgnoreMatcher,
   callback: Callback,
-  enableSymlinks?: boolean,
+  enableSymlinks: boolean,
 ): void {
   const result: Result = [];
   let activeCalls = 0;

From c497fcb2061dad59dfb554f99c22209f33db6888 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Mon, 2 Nov 2020 09:28:53 +0100
Subject: [PATCH 09/13] correct watchman comment

---
 docs/Configuration.md             | 2 +-
 packages/jest-types/src/Config.ts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/Configuration.md b/docs/Configuration.md
index 8a0b7cb1df02..1a3138aefdc3 100644
--- a/docs/Configuration.md
+++ b/docs/Configuration.md
@@ -479,7 +479,7 @@ type HasteConfig = {
   /**
    * Whether to follow symlinks when crawling for files.
    *   This options cannot be used in projects which use watchman.
-   *   Projects with a .watchmanconfig will error if this option is set to true.
+   *   Projects with `watchman` set to true will error if this option is set to true.
    */
   enableSymlinks?: boolean;
   /** Path to a custom implementation of Haste. */
diff --git a/packages/jest-types/src/Config.ts b/packages/jest-types/src/Config.ts
index 206b5868ae70..9b8da96249eb 100644
--- a/packages/jest-types/src/Config.ts
+++ b/packages/jest-types/src/Config.ts
@@ -25,7 +25,7 @@ export type HasteConfig = {
   /**
    * Whether to follow symlinks when crawling for files.
    *   This options cannot be used in projects which use watchman.
-   *   Projects with a .watchmanconfig will error if this option is set to true.
+   *   Projects with `watchman` set to true will error if this option is set to true.
    */
   enableSymlinks?: boolean;
   /** Path to a custom implementation of Haste. */

From f1c70498769495abd32f83390538d976fc99aaca Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Mon, 2 Nov 2020 09:39:14 +0100
Subject: [PATCH 10/13] cleanup test

---
 e2e/__tests__/crawlSymlinks.test.ts | 34 ++++++++++-------------------
 1 file changed, 11 insertions(+), 23 deletions(-)

diff --git a/e2e/__tests__/crawlSymlinks.test.ts b/e2e/__tests__/crawlSymlinks.test.ts
index 8f59213ff0ae..f09fe7f39001 100644
--- a/e2e/__tests__/crawlSymlinks.test.ts
+++ b/e2e/__tests__/crawlSymlinks.test.ts
@@ -14,17 +14,7 @@ const DIR = path.resolve(tmpdir(), 'crawl-symlinks-test');
 
 beforeEach(() => {
   cleanup(DIR);
-});
-
-afterEach(() => {
-  cleanup(DIR);
-});
 
-function init(
-  extraFiles: {
-    [filename: string]: string;
-  } = {},
-) {
   writeFiles(DIR, {
     'package.json': JSON.stringify({
       jest: {
@@ -32,19 +22,21 @@ function init(
       },
     }),
     'symlinked-files/test.js': `
-            test('1+1', () => {
-              expect(1).toBe(1);
-            });
-          `,
-    ...extraFiles,
+      test('1+1', () => {
+        expect(1).toBe(1);
+      });
+    `,
   });
 
   writeSymlinks(DIR, {
     'symlinked-files/test.js': 'test-files/test.js',
   });
-}
+});
+
+afterEach(() => {
+  cleanup(DIR);
+});
 
-const noWatchman = '--no-watchman';
 test('Node crawler picks up symlinked files when option is set as flag', () => {
   // Symlinks are only enabled on windows with developer mode.
   // https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
@@ -52,10 +44,9 @@ test('Node crawler picks up symlinked files when option is set as flag', () => {
     return;
   }
 
-  init();
   const {stdout, stderr, exitCode} = runJest(DIR, [
     '--haste={"enableSymlinks": true}',
-    noWatchman,
+    '--no-watchman',
   ]);
 
   expect(stdout).toEqual('');
@@ -64,16 +55,13 @@ test('Node crawler picks up symlinked files when option is set as flag', () => {
 });
 
 test('Node crawler does not pick up symlinked files by default', () => {
-  init();
-  const {stdout, stderr, exitCode} = runJest(DIR, [noWatchman]);
+  const {stdout, stderr, exitCode} = runJest(DIR, ['--no-watchman']);
   expect(stdout).toContain('No tests found, exiting with code 1');
   expect(stderr).toEqual('');
   expect(exitCode).toEqual(1);
 });
 
 test('Should throw if watchman used with haste.enableSymlinks', () => {
-  init({'.watchmanconfig': JSON.stringify({})});
-
   // it should throw both if watchman is explicitly provided and not
   const run1 = runJest(DIR, ['--haste={"enableSymlinks": true}']);
   const run2 = runJest(DIR, ['--haste={"enableSymlinks": true}', '--watchman']);

From 30a07e16b53c81b35a9fb4f24993d8accf982199 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Mon, 2 Nov 2020 10:26:04 +0100
Subject: [PATCH 11/13] pass callback as last arg

---
 packages/jest-haste-map/src/crawlers/node.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/jest-haste-map/src/crawlers/node.ts b/packages/jest-haste-map/src/crawlers/node.ts
index d336f8c886e6..075498c4702a 100644
--- a/packages/jest-haste-map/src/crawlers/node.ts
+++ b/packages/jest-haste-map/src/crawlers/node.ts
@@ -60,8 +60,8 @@ function find(
   roots: Array<string>,
   extensions: Array<string>,
   ignore: IgnoreMatcher,
-  callback: Callback,
   enableSymlinks: boolean,
+  callback: Callback,
 ): void {
   const result: Result = [];
   let activeCalls = 0;
@@ -140,8 +140,8 @@ function findNative(
   roots: Array<string>,
   extensions: Array<string>,
   ignore: IgnoreMatcher,
-  callback: Callback,
   enableSymlinks: boolean,
+  callback: Callback,
 ): void {
   const args = Array.from(roots);
   if (enableSymlinks) {
@@ -242,9 +242,9 @@ export = async function nodeCrawl(
     };
 
     if (useNativeFind) {
-      findNative(roots, extensions, ignore, callback, enableSymlinks);
+      findNative(roots, extensions, ignore, enableSymlinks, callback);
     } else {
-      find(roots, extensions, ignore, callback, enableSymlinks);
+      find(roots, extensions, ignore, enableSymlinks, callback);
     }
   });
 };

From dcda5ba7f01fbf8fc50bb758dacad057b1e18243 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Thu, 1 Apr 2021 11:02:32 +0200
Subject: [PATCH 12/13] move changelog entry

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cbc281c8230e..2220d15ea6b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@
 - `[jest-environment-node]` Add AbortController to globals ([#11182](https://github.com/facebook/jest/pull/11182))
 - `[@jest/fake-timers]` Update to `@sinonjs/fake-timers` to v7 ([#11198](https://github.com/facebook/jest/pull/11198))
 - `[jest-haste-map]` Handle injected scm clocks ([#10966](https://github.com/facebook/jest/pull/10966))
+- `[jest-haste-map]` Add `enableSymlinks` configuration option to follow symlinks for test files ([#9351](https://github.com/facebook/jest/pull/9351))
 - `[jest-repl, jest-runner]` [**BREAKING**] Run transforms over environment ([#8751](https://github.com/facebook/jest/pull/8751))
 - `[jest-runner]` [**BREAKING**] set exit code to 1 if test logs after teardown ([#10728](https://github.com/facebook/jest/pull/10728))
 - `[jest-runner]` [**BREAKING**] Run transforms over `runnner` ([#8823](https://github.com/facebook/jest/pull/8823))
@@ -120,7 +121,6 @@
 ### Features
 
 - `[jest-core]` Add `findRelatedTests` and `nonFlagArgs` in allowed config options for `updateConfigAndRun` in watch plugins ([#10659](https://github.com/facebook/jest/pull/10659))
-- `[jest-haste-map]` Add `enableSymlinks` configuration option to follow symlinks for test files ([#9350](https://github.com/facebook/jest/issues/9350))
 
 ### Fixes
 

From 88cfea0062f7d6ea26171a5ad26259ce1c3fd3d2 Mon Sep 17 00:00:00 2001
From: Simen Bekkhus <sbekkhus91@gmail.com>
Date: Thu, 1 Apr 2021 12:12:59 +0200
Subject: [PATCH 13/13] normalize is async now

---
 packages/jest-config/src/__tests__/normalize.test.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/jest-config/src/__tests__/normalize.test.ts b/packages/jest-config/src/__tests__/normalize.test.ts
index f3530f502f70..1000d1e10c14 100644
--- a/packages/jest-config/src/__tests__/normalize.test.ts
+++ b/packages/jest-config/src/__tests__/normalize.test.ts
@@ -1844,19 +1844,19 @@ describe('extensionsToTreatAsEsm', () => {
 });
 
 describe('haste.enableSymlinks', () => {
-  it('should throw if watchman is not disabled', () => {
-    expect(() =>
+  it('should throw if watchman is not disabled', async () => {
+    await expect(
       normalize({haste: {enableSymlinks: true}, rootDir: '/root/'}, {}),
-    ).toThrow('haste.enableSymlinks is incompatible with watchman');
+    ).rejects.toThrow('haste.enableSymlinks is incompatible with watchman');
 
-    expect(() =>
+    await expect(
       normalize(
         {haste: {enableSymlinks: true}, rootDir: '/root/', watchman: true},
         {},
       ),
-    ).toThrow('haste.enableSymlinks is incompatible with watchman');
+    ).rejects.toThrow('haste.enableSymlinks is incompatible with watchman');
 
-    const {options} = normalize(
+    const {options} = await normalize(
       {haste: {enableSymlinks: true}, rootDir: '/root/', watchman: false},
       {},
     );