Merge branch 'runtime-require-resolve-outside' into uglier-inline-sna…

…pshots

* runtime-require-resolve-outside:
  lint
  review improvements
  implement require.resolve option outsideJestVm for internal modules only
  basic jest-runtime require.resolve test
  Fix dead link to coverage CLI option (jestjs#9905)
  chore: remove dated node 6 reference from docs (jestjs#9895)
  Use the new serializer plugin API in example (jestjs#9847)
  chore: remove unused catch clauses (jestjs#9893)

docs/Configuration.md

@@ -830,8 +830,8 @@ Example serializer module:
 ```js
 // my-serializer-module
 module.exports = {
-  print(val, serialize, indent) {
-    return 'Pretty foo: ' + serialize(val.foo);
+  serialize(val, config, indentation, depth, refs, printer) {
+    return 'Pretty foo: ' + printer(val.foo);
   },
 
   test(val) {
@@ -840,7 +840,7 @@ module.exports = {
 };
 ```
 
-`serialize` is a function that serializes a value using existing plugins.
+`printer` is a function that serializes a value using existing plugins.
 
 To use `my-serializer-module` as a serializer, configuration would be as follows:
 
@@ -879,6 +879,8 @@ Pretty foo: Object {
 
 To make a dependency explicit instead of implicit, you can call [`expect.addSnapshotSerializer`](ExpectAPI.md#expectaddsnapshotserializerserializer) to add a module for an individual test file instead of adding its path to `snapshotSerializers` in Jest configuration.
 
+More about serializers API can be found [here](https://github.com/facebook/jest/tree/master/packages/pretty-format/README.md#serialize).
+
 ### `testEnvironment` [string]
 
 Default: `"jsdom"`

docs/Troubleshooting.md

@@ -184,10 +184,6 @@ jest --maxWorkers=4
 yarn test --maxWorkers=4
 ```
 
-## Compatibility issues
-
-Jest takes advantage of new features added to Node 6. We recommend that you upgrade to the latest stable release of Node. The minimum supported version is `v6.0.0`. Versions `0.x.x` and `4.x.x` are not supported because the `jsdom` version used in Jest doesn't support Node 4. However, if you need to run Jest on Node 4, you can use the `testEnvironment` config to use a [custom environment](https://jestjs.io/docs/en/configuration.html#testenvironment-string) that supports Node 4, such as [`jest-environment-node`](https://yarnpkg.com/en/package/jest-environment-node).
-
 ## `coveragePathIgnorePatterns` seems to not have any effect.
 
 Make sure you are not using the `babel-plugin-istanbul` plugin. Jest wraps Istanbul, and therefore also tells Istanbul what files to instrument with coverage collection. When using `babel-plugin-istanbul`, every file that is processed by Babel will have coverage collection code, hence it is not being ignored by `coveragePathIgnorePatterns`.

packages/jest-resolve/src/index.ts

@@ -218,7 +218,7 @@ class Resolver {
           resolveNodeModule(module) || require.resolve(module);
         this._moduleNameCache.set(key, resolvedModule);
         return resolvedModule;
-      } catch (ignoredError) {}
+      } catch {}
     }
 
     return null;

packages/jest-runtime/src/__tests__/runtime_require_resolve.test.ts

@@ -0,0 +1,66 @@
+/**
+ * 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 type {Config} from '@jest/types';
+import type Runtime from '..';
+
+let createRuntime: (
+  path: string,
+  config?: Config.InitialOptions,
+) => Promise<Runtime & {__mockRootPath: string}>;
+
+describe('Runtime require.resolve', () => {
+  beforeEach(() => {
+    createRuntime = require('createRuntime');
+  });
+
+  it('resolves a module path', async () => {
+    const runtime = await createRuntime(__filename);
+    const resolved = runtime.requireModule(
+      runtime.__mockRootPath,
+      './resolve_self.js',
+    );
+    expect(resolved).toEqual(require.resolve('./test_root/resolve_self.js'));
+  });
+
+  it('resolves a module path with moduleNameMapper', async () => {
+    const runtime = await createRuntime(__filename, {
+      moduleNameMapper: {
+        '^testMapped/(.*)': '<rootDir>/mapped_dir/$1',
+      },
+    });
+    const resolved = runtime.requireModule(
+      runtime.__mockRootPath,
+      './resolve_mapped.js',
+    );
+    expect(resolved).toEqual(
+      require.resolve('./test_root/mapped_dir/moduleInMapped.js'),
+    );
+  });
+
+  describe('with the outsideJestVm option', () => {
+    it('forwards to the real Node require in an internal context', async () => {
+      const runtime = await createRuntime(__filename);
+      const module = runtime.requireInternalModule(
+        runtime.__mockRootPath,
+        './resolve_and_require_outside.js',
+      );
+      expect(module).toBe(require('./test_root/create_require_module'));
+    });
+
+    it('ignores the option in an external context', async () => {
+      const runtime = await createRuntime(__filename);
+      const module = runtime.requireModule<any>(
+        runtime.__mockRootPath,
+        './resolve_and_require_outside.js',
+      );
+      expect(module.foo).toBe('foo');
+      expect(module).not.toBe(require('./test_root/create_require_module'));
+    });
+  });
+});

packages/jest-runtime/src/__tests__/test_root/resolve_and_require_outside.js

@@ -0,0 +1,14 @@
+/**
+ * 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.
+ */
+
+'use strict';
+
+const path = require.resolve('./create_require_module', {outsideJestVm: true});
+if (typeof path !== 'string') {
+  throw new Error('require.resolve not spec-compliant: must return a string');
+}
+module.exports = require(path);

packages/jest-runtime/src/__tests__/test_root/resolve_mapped.js

@@ -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.
+ */
+
+'use strict';
+
+module.exports = require.resolve('testMapped/moduleInMapped');

packages/jest-runtime/src/__tests__/test_root/resolve_self.js

@@ -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.
+ */
+
+'use strict';
+
+module.exports = require.resolve('./resolve_self');

packages/jest-runtime/src/helpers.ts

@@ -10,6 +10,25 @@ import slash = require('slash');
 import glob = require('glob');
 import type {Config} from '@jest/types';
 
+const OUTSIDE_JEST_VM_PROTOCOL = 'jest-main:';
+// String manipulation is easier here, fileURLToPath is only in newer Nodes,
+// plus setting non-standard protocols on URL objects is difficult.
+export const createOutsideJestVmPath = (path: string): string =>
+  OUTSIDE_JEST_VM_PROTOCOL + '//' + encodeURIComponent(path);
+export const decodePossibleOutsideJestVmPath = (
+  outsideJestVmPath: string,
+): string | undefined => {
+  if (outsideJestVmPath.startsWith(OUTSIDE_JEST_VM_PROTOCOL)) {
+    return decodeURIComponent(
+      outsideJestVmPath.replace(
+        new RegExp('^' + OUTSIDE_JEST_VM_PROTOCOL + '//'),
+        '',
+      ),
+    );
+  }
+  return undefined;
+};
+
 export const findSiblingsWithFileExtension = (
   moduleFileExtensions: Config.ProjectConfig['moduleFileExtensions'],
   from: Config.Path,
@@ -48,7 +67,7 @@ export const findSiblingsWithFileExtension = (
           `[${mappedModuleFileExtensions}].\n\nSee https://jestjs.io/docs/en/configuration#modulefileextensions-arraystring`
         );
       }
-    } catch (ignored) {}
+    } catch {}
   }
 
   return '';

packages/jest-runtime/src/index.ts

@@ -45,7 +45,11 @@ import {CoverageInstrumenter, V8Coverage} from 'collect-v8-coverage';
 import * as fs from 'graceful-fs';
 import {run as cliRun} from './cli';
 import {options as cliOptions} from './cli/args';
-import {findSiblingsWithFileExtension} from './helpers';
+import {
+  createOutsideJestVmPath,
+  decodePossibleOutsideJestVmPath,
+  findSiblingsWithFileExtension,
+} from './helpers';
 import type {Context as JestContext} from './types';
 import jestMock = require('jest-mock');
 import HasteMap = require('jest-haste-map');
@@ -81,7 +85,10 @@ const defaultTransformOptions: InternalModuleOptions = {
 type InitialModule = Partial<Module> &
   Pick<Module, 'children' | 'exports' | 'filename' | 'id' | 'loaded'>;
 type ModuleRegistry = Map<string, InitialModule | Module>;
-type ResolveOptions = Parameters<typeof require.resolve>[1];
+
+type ResolveOptions = Parameters<typeof require.resolve>[1] & {
+  outsideJestVm?: true;
+};
 
 type BooleanObject = Record<string, boolean>;
 type CacheFS = {[path: string]: string};
@@ -534,6 +541,13 @@ class Runtime {
   }
 
   requireInternalModule<T = unknown>(from: Config.Path, to?: string): T {
+    if (to) {
+      const outsideJestVmPath = decodePossibleOutsideJestVmPath(to);
+      if (outsideJestVmPath) {
+        return require(outsideJestVmPath);
+      }
+    }
+
     return this.requireModule(from, to, {
       isInternalModule: true,
       supportsDynamicImport: false,
@@ -1269,9 +1283,17 @@ class Runtime {
     from: InitialModule,
     options?: InternalModuleOptions,
   ): LocalModuleRequire {
-    // TODO: somehow avoid having to type the arguments - they should come from `NodeRequire/LocalModuleRequire.resolve`
-    const resolve = (moduleName: string, options: ResolveOptions) =>
-      this._requireResolve(from.filename, moduleName, options);
+    const resolve = (moduleName: string, resolveOptions?: ResolveOptions) => {
+      const resolved = this._requireResolve(
+        from.filename,
+        moduleName,
+        resolveOptions,
+      );
+      if (resolveOptions?.outsideJestVm && options?.isInternalModule) {
+        return createOutsideJestVmPath(resolved);
+      }
+      return resolved;
+    };
     resolve.paths = (moduleName: string) =>
       this._requireResolvePaths(from.filename, moduleName);
 

packages/jest-worker/src/WorkerPool.ts

@@ -20,7 +20,7 @@ const canUseWorkerThreads = () => {
   try {
     require('worker_threads');
     return true;
-  } catch (_) {
+  } catch {
     return false;
   }
 };

website/pages/en/index.js

@@ -376,7 +376,7 @@ class Index extends React.Component {
                   content: (
                     <translate>
                       Generate code coverage by adding the flag
-                      [`--coverage`](https://jestjs.io/docs/en/cli.html#coverage).
+                      [`--coverage`](https://jestjs.io/docs/en/cli.html#--coverageboolean).
                       No additional setup needed. Jest can collect code coverage
                       information from entire projects, including untested
                       files.

website/versioned_docs/version-22.x/Configuration.md

@@ -598,8 +598,8 @@ Example serializer module:
 ```js
 // my-serializer-module
 module.exports = {
-  print(val, serialize, indent) {
-    return 'Pretty foo: ' + serialize(val.foo);
+  serialize(val, config, indentation, depth, refs, printer) {
+    return 'Pretty foo: ' + printer(val.foo);
   },
 
   test(val) {
@@ -608,7 +608,7 @@ module.exports = {
 };
 ```
 
-`serialize` is a function that serializes a value using existing plugins.
+`printer` is a function that serializes a value using existing plugins.
 
 To use `my-serializer-module` as a serializer, configuration would be as follows:
 
@@ -647,6 +647,8 @@ Pretty foo: Object {
 
 To make a dependency explicit instead of implicit, you can call [`expect.addSnapshotSerializer`](ExpectAPI.md#expectaddsnapshotserializerserializer) to add a module for an individual test file instead of adding its path to `snapshotSerializers` in Jest configuration.
 
+More about serializers API can be found [here](https://github.com/facebook/jest/tree/master/packages/pretty-format#serialize).
+
 ### `testEnvironment` [string]
 
 Default: `"jsdom"`

website/versioned_docs/version-23.x/Configuration.md

@@ -662,8 +662,8 @@ Example serializer module:
 ```js
 // my-serializer-module
 module.exports = {
-  print(val, serialize, indent) {
-    return 'Pretty foo: ' + serialize(val.foo);
+  serialize(val, config, indentation, depth, refs, printer) {
+    return 'Pretty foo: ' + printer(val.foo);
   },
 
   test(val) {
@@ -672,7 +672,7 @@ module.exports = {
 };
 ```
 
-`serialize` is a function that serializes a value using existing plugins.
+`printer` is a function that serializes a value using existing plugins.
 
 To use `my-serializer-module` as a serializer, configuration would be as follows:
 
@@ -711,6 +711,8 @@ Pretty foo: Object {
 
 To make a dependency explicit instead of implicit, you can call [`expect.addSnapshotSerializer`](ExpectAPI.md#expectaddsnapshotserializerserializer) to add a module for an individual test file instead of adding its path to `snapshotSerializers` in Jest configuration.
 
+More about serializers API can be found [here](https://github.com/facebook/jest/tree/master/packages/pretty-format#serialize).
+
 ### `testEnvironment` [string]
 
 Default: `"jsdom"`

website/versioned_docs/version-24.x/Configuration.md

@@ -807,8 +807,8 @@ Example serializer module:
 ```js
 // my-serializer-module
 module.exports = {
-  print(val, serialize, indent) {
-    return 'Pretty foo: ' + serialize(val.foo);
+  serialize(val, config, indentation, depth, refs, printer) {
+    return 'Pretty foo: ' + printer(val.foo);
   },
 
   test(val) {
@@ -817,7 +817,7 @@ module.exports = {
 };
 ```
 
-`serialize` is a function that serializes a value using existing plugins.
+`printer` is a function that serializes a value using existing plugins.
 
 To use `my-serializer-module` as a serializer, configuration would be as follows:
 
@@ -856,6 +856,8 @@ Pretty foo: Object {
 
 To make a dependency explicit instead of implicit, you can call [`expect.addSnapshotSerializer`](ExpectAPI.md#expectaddsnapshotserializerserializer) to add a module for an individual test file instead of adding its path to `snapshotSerializers` in Jest configuration.
 
+More about serializers API can be found [here](https://github.com/facebook/jest/tree/master/packages/pretty-format#serialize).
+
 ### `testEnvironment` [string]
 
 Default: `"jsdom"`

website/versioned_docs/version-25.1/Configuration.md

@@ -818,8 +818,8 @@ Example serializer module:
 ```js
 // my-serializer-module
 module.exports = {
-  print(val, serialize, indent) {
-    return 'Pretty foo: ' + serialize(val.foo);
+  serialize(val, config, indentation, depth, refs, printer) {
+    return 'Pretty foo: ' + printer(val.foo);
   },
 
   test(val) {
@@ -828,7 +828,7 @@ module.exports = {
 };
 ```
 
-`serialize` is a function that serializes a value using existing plugins.
+`printer` is a function that serializes a value using existing plugins.
 
 To use `my-serializer-module` as a serializer, configuration would be as follows:
 
@@ -867,6 +867,8 @@ Pretty foo: Object {
 
 To make a dependency explicit instead of implicit, you can call [`expect.addSnapshotSerializer`](ExpectAPI.md#expectaddsnapshotserializerserializer) to add a module for an individual test file instead of adding its path to `snapshotSerializers` in Jest configuration.
 
+More about serializers API can be found [here](https://github.com/facebook/jest/tree/master/packages/pretty-format#serialize).
+
 ### `testEnvironment` [string]
 
 Default: `"jsdom"`