Support both environment variable and --preserve-symlinks node flag

e2e/__tests__/__snapshots__/moduleNameMapper.test.ts.snap

@@ -36,7 +36,7 @@ FAIL __tests__/index.js
       12 | module.exports = () => 'test';
       13 | 
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/index.js:551:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/index.js:561:17)
       at Object.require (index.js:10:1)
 `;
 
@@ -65,6 +65,6 @@ FAIL __tests__/index.js
       12 | module.exports = () => 'test';
       13 | 
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/index.js:551:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/index.js:561:17)
       at Object.require (index.js:10:1)
 `;

e2e/__tests__/__snapshots__/resolveNoFileExtensions.test.ts.snap

@@ -37,6 +37,6 @@ FAIL __tests__/test.js
         |                  ^
       9 | 
 
-      at Resolver.resolveModule (../../packages/jest-resolve/build/index.js:305:11)
+      at Resolver.resolveModule (../../packages/jest-resolve/build/index.js:315:11)
       at Object.require (index.js:8:18)
 `;

e2e/__tests__/preserveSymlinks.ts

@@ -53,7 +53,7 @@ afterAll(() => {
   cleanup();
 });
 
-test('preserving symlinks', () => {
+test('preserving symlinks with environment variable', () => {
   const {stderr, exitCode} = runJest('preserve-symlinks', ['--no-watchman'], {
     preserveSymlinks: '1',
   });
@@ -68,6 +68,21 @@ test('preserving symlinks', () => {
   expect(summary).toMatch('Snapshots:   0 total');
 });
 
+test('preserving symlinks with --preserve-symlinks node flag', () => {
+  const {stderr, exitCode} = runJest('preserve-symlinks', ['--no-watchman'], {
+    nodeFlags: ['--preserve-symlinks'],
+  });
+  const {summary, rest} = extractSummary(stderr);
+  expect(exitCode).toEqual(0);
+  expect(rest.split('\n').length).toEqual(3);
+  expect(rest).toMatch('PASS __tests__/ab.test.js');
+  expect(rest).toMatch('PASS __tests__/a.test.js');
+  expect(rest).toMatch('PASS __tests__/b.test.js');
+  expect(summary).toMatch('Test Suites: 3 passed, 3 total');
+  expect(summary).toMatch('Tests:       3 passed, 3 total');
+  expect(summary).toMatch('Snapshots:   0 total');
+});
+
 test('hasteMap finds symlinks correctly', async () => {
   const options = {
     extensions: ['js'],
@@ -102,3 +117,9 @@ test('hasteMap finds symlinks correctly', async () => {
     expect(files).toContain(f);
   });
 });
+
+test('no preserve symlinks configuration', () => {
+  const {exitCode, stdout} = runJest('preserve-symlinks', ['--no-watchman']);
+  expect(exitCode).toEqual(1);
+  expect(stdout).toMatch('No tests found, exiting with code 1');
+});

e2e/runJest.ts

@@ -19,6 +19,7 @@ const JEST_PATH = path.resolve(__dirname, '../packages/jest-cli/bin/jest.js');
 
 type RunJestOptions = {
   preserveSymlinks?: string;
+  nodeFlags?: Array<string>;
   nodeOptions?: string;
   nodePath?: string;
   skipPkgJsonCheck?: boolean; // don't complain if can't find package.json
@@ -75,13 +76,15 @@ function spawnJest(
     );
   }
   const env = Object.assign({}, process.env, {FORCE_COLOR: '0'});
-
   if (options.nodeOptions) env['NODE_OPTIONS'] = options.nodeOptions;
   if (options.nodePath) env['NODE_PATH'] = options.nodePath;
   if (options.preserveSymlinks)
     env['NODE_PRESERVE_SYMLINKS'] = options.preserveSymlinks;
 
   const spawnArgs = [JEST_PATH, ...args];
+  if (options.nodeFlags) {
+    spawnArgs.unshift(...options.nodeFlags);
+  }
   const spawnOptions = {
     cwd: dir,
     env,

packages/jest-cli/package.json

@@ -12,6 +12,7 @@
     }
   },
   "dependencies": {
+    "should-preserve-links": "^1.0.0",
     "@jest/core": "^25.4.0",
     "@jest/test-result": "^25.4.0",
     "@jest/types": "^25.4.0",
@@ -79,4 +80,4 @@
     "access": "public"
   },
   "gitHead": "170eee11d03b0ed5c60077982fdbc3bafd403638"
-}
+}

packages/jest-cli/should-preserve-links.d.ts

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+declare module 'should-preserve-links' {
+  export default function shouldPreserveLinks(): boolean;
+}

packages/jest-cli/src/cli/index.ts

@@ -16,12 +16,13 @@ import chalk = require('chalk');
 import exit = require('exit');
 import yargs = require('yargs');
 import {sync as _realpath} from 'realpath-native';
+import shouldPreserveSymlinks from 'should-preserve-links';
 import init from '../init';
 import * as args from './args';
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 export async function run(

packages/jest-cli/src/init/index.ts

@@ -11,6 +11,7 @@ import chalk = require('chalk');
 import prompts = require('prompts');
 import {sync as _realpath} from 'realpath-native';
 import {constants} from 'jest-config';
+import shouldPreserveSymlinks from 'should-preserve-links';
 import defaultQuestions, {testScriptQuestion} from './questions';
 import {MalformedPackageJsonError, NotFoundPackageJsonError} from './errors';
 import generateConfigFile from './generate_config_file';
@@ -32,9 +33,9 @@ type PromptsResults = {
   scripts: boolean;
 };
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 const getConfigFilename = (ext: string) => JEST_CONFIG_BASE_NAME + ext;

packages/jest-config/package.json

@@ -17,6 +17,7 @@
     }
   },
   "dependencies": {
+    "should-preserve-links": "^1.0.0",
     "@babel/core": "^7.1.0",
     "@jest/test-sequencer": "^25.4.0",
     "@jest/types": "^25.4.0",
@@ -48,4 +49,4 @@
     "access": "public"
   },
   "gitHead": "170eee11d03b0ed5c60077982fdbc3bafd403638"
-}
+}

packages/jest-config/should-preserve-links.d.ts

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+declare module 'should-preserve-links' {
+  export default function shouldPreserveLinks(): boolean;
+}

packages/jest-config/src/getCacheDirectory.ts

@@ -9,9 +9,11 @@ import * as path from 'path';
 import {tmpdir} from 'os';
 import {sync as _realpath} from 'realpath-native';
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+import shouldPreserveSymlinks from 'should-preserve-links';
+
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 const getCacheDirectory = () => {

packages/jest-config/src/index.ts

@@ -10,6 +10,7 @@ import * as path from 'path';
 import type {Config} from '@jest/types';
 import chalk = require('chalk');
 import {sync as _realpath} from 'realpath-native';
+import shouldPreserveSymlinks from 'should-preserve-links';
 import {isJSONString, replaceRootDirInPath} from './utils';
 import normalize from './normalize';
 import resolveConfigPath from './resolveConfigPath';
@@ -23,9 +24,9 @@ export {default as descriptions} from './Descriptions';
 import * as constants from './constants';
 export {constants};
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 type ReadConfig = {

packages/jest-config/src/normalize.ts

@@ -18,6 +18,7 @@ import {sync as _realpath} from 'realpath-native';
 import Resolver = require('jest-resolve');
 import {replacePathSepForRegex} from 'jest-regex-util';
 import merge = require('deepmerge');
+import shouldPreserveSymlinks from 'should-preserve-links';
 import validatePattern from './validatePattern';
 import getMaxWorkers from './getMaxWorkers';
 import {
@@ -45,9 +46,9 @@ const PRESET_NAME = 'jest-preset';
 
 type AllOptions = Config.ProjectConfig & Config.GlobalConfig;
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 const createConfigError = (message: string) =>

packages/jest-core/package.json

@@ -12,6 +12,7 @@
     }
   },
   "dependencies": {
+    "should-preserve-links": "^1.0.0",
     "@jest/console": "^25.4.0",
     "@jest/reporters": "^25.4.0",
     "@jest/test-result": "^25.4.0",
@@ -93,4 +94,4 @@
     "access": "public"
   },
   "gitHead": "170eee11d03b0ed5c60077982fdbc3bafd403638"
-}
+}

packages/jest-core/should-preserve-links.d.ts

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+declare module 'should-preserve-links' {
+  export default function shouldPreserveLinks(): boolean;
+}

packages/jest-core/src/runJest.ts

@@ -23,6 +23,7 @@ import {
 } from '@jest/test-result';
 import type TestSequencer from '@jest/test-sequencer';
 import type {ChangedFiles, ChangedFilesPromise} from 'jest-changed-files';
+import shouldPreserveSymlinks from 'should-preserve-links';
 import getNoTestsFoundMessage from './getNoTestsFoundMessage';
 import runGlobalHook from './runGlobalHook';
 import SearchSource from './SearchSource';
@@ -32,9 +33,9 @@ import collectNodeHandles from './collectHandles';
 import type TestWatcher from './TestWatcher';
 import type {Filter, TestRunData} from './types';
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 const getTestPaths = async (

packages/jest-haste-map/package.json

@@ -17,6 +17,7 @@
     }
   },
   "dependencies": {
+    "should-preserve-links": "^1.0.0",
     "@jest/types": "^25.4.0",
     "anymatch": "^3.0.3",
     "fb-watchman": "^2.0.0",
@@ -49,4 +50,4 @@
     "access": "public"
   },
   "gitHead": "170eee11d03b0ed5c60077982fdbc3bafd403638"
-}
+}

packages/jest-haste-map/should-preserve-links.d.ts

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+declare module 'should-preserve-links' {
+  export default function shouldPreserveLinks(): boolean;
+}

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

@@ -15,6 +15,7 @@ import {NodeWatcher, Watcher as SaneWatcher} from 'sane';
 import type {Config} from '@jest/types';
 import serializer from 'jest-serializer';
 import Worker from 'jest-worker';
+import shouldPreserveSymlinks from 'should-preserve-links';
 import {getSha1, worker} from './worker';
 import getMockName from './getMockName';
 import getPlatformExtension from './lib/getPlatformExtension';
@@ -45,6 +46,8 @@ import type {
   WorkerMetadata,
 } from './types';
 
+const preserveSymlinks = shouldPreserveSymlinks();
+
 type HType = typeof H;
 
 type Options = {
@@ -269,8 +272,7 @@ class HasteMap extends EventEmitter {
         : null,
       name: options.name,
       platforms: options.platforms,
-      preserveSymlinks:
-        options.preserveSymlinks || Boolean(process.env.NODE_PRESERVE_SYMLINKS),
+      preserveSymlinks: options.preserveSymlinks || preserveSymlinks,
       resetCache: options.resetCache,
       retainAllFiles: options.retainAllFiles,
       rootDir: options.rootDir,

packages/jest-resolve/package.json

@@ -17,6 +17,7 @@
     }
   },
   "dependencies": {
+    "should-preserve-links": "^1.0.0",
     "@jest/types": "^25.4.0",
     "browser-resolve": "^1.11.3",
     "chalk": "^3.0.0",
@@ -38,4 +39,4 @@
     "access": "public"
   },
   "gitHead": "170eee11d03b0ed5c60077982fdbc3bafd403638"
-}
+}

packages/jest-resolve/should-preserve-links.d.ts

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+declare module 'should-preserve-links' {
+  export default function shouldPreserveLinks(): boolean;
+}

packages/jest-resolve/src/defaultResolver.ts

@@ -12,9 +12,11 @@ import {sync as _realpath} from 'realpath-native';
 import pnpResolver from 'jest-pnp-resolver';
 import type {Config} from '@jest/types';
 
-const PRESERVE_SYMLINKS = process.env.NODE_PRESERVE_SYMLINKS;
+import shouldPreserveSymlinks from 'should-preserve-links';
+
+const preserveSymlinks = shouldPreserveSymlinks();
 function realpath(p: string) {
-  return PRESERVE_SYMLINKS ? p : _realpath(p);
+  return preserveSymlinks ? p : _realpath(p);
 }
 
 type ResolverOptions = {
@@ -45,7 +47,7 @@ export default function defaultResolver(
     isFile,
     moduleDirectory: options.moduleDirectory,
     paths: options.paths,
-    preserveSymlinks: Boolean(PRESERVE_SYMLINKS),
+    preserveSymlinks,
     // @ts-ignore: https://github.com/DefinitelyTyped/DefinitelyTyped/pull/44137
     realpathSync,
   });