Jest-internal sandbox escape hatch (#9907)

CHANGELOG.md

@@ -16,6 +16,7 @@
 - `[docs]` Correct confusing filename in `enableAutomock` example ([#10055](https://github.com/facebook/jest/pull/10055))
 - `[jest-core]` 🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉🎉 ([#10000](https://github.com/facebook/jest/pull/10000))
 - `[jest-core, jest-reporters, jest-test-result, jest-types]` Cleanup `displayName` type ([#10049](https://github.com/facebook/jest/pull/10049))
+- `[jest-runtime]` Jest-internal sandbox escape hatch ([#9907](https://github.com/facebook/jest/pull/9907))
 
 ### Performance
 

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

@@ -0,0 +1,84 @@
+/**
+ * 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 '..';
+import {createOutsideJestVmPath} from '../helpers';
+
+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 OUTSIDE_JEST_VM_RESOLVE_OPTION', () => {
+    it('forwards to the real Node require in an internal context', async () => {
+      const runtime = await createRuntime(__filename);
+      const module = runtime.requireInternalModule<any>(
+        runtime.__mockRootPath,
+        './resolve_and_require_outside.js',
+      );
+      expect(module.required).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.required.foo).toBe('foo');
+      expect(module.required).not.toBe(
+        require('./test_root/create_require_module'),
+      );
+    });
+
+    // make sure we also check isInternal during require, not just during resolve
+    it('does not understand a self-constructed outsideJestVmPath in an external context', async () => {
+      const runtime = await createRuntime(__filename);
+      expect(() =>
+        runtime.requireModule<any>(
+          runtime.__mockRootPath,
+          createOutsideJestVmPath(
+            require.resolve('./test_root/create_require_module.js'),
+          ),
+        ),
+      ).toThrow(/cannot find.+create_require_module/i);
+    });
+  });
+});

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

@@ -0,0 +1,19 @@
+/**
+ * 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 resolved = require.resolve('./create_require_module', {
+  [Symbol.for('OUTSIDE_JEST_VM_RESOLVE_OPTION')]: true,
+});
+if (typeof resolved !== 'string') {
+  throw new Error('require.resolve not spec-compliant: must return a string');
+}
+module.exports = {
+  required: require(resolved),
+  resolved,
+};

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,

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 +85,13 @@ 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];
+
+const OUTSIDE_JEST_VM_RESOLVE_OPTION = Symbol.for(
+  'OUTSIDE_JEST_VM_RESOLVE_OPTION',
+);
+type ResolveOptions = Parameters<typeof require.resolve>[1] & {
+  [OUTSIDE_JEST_VM_RESOLVE_OPTION]?: true;
+};
 
 type StringMap = Map<string, string>;
 type BooleanMap = Map<string, boolean>;
@@ -547,6 +557,13 @@ 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,
@@ -1307,9 +1324,20 @@ class Runtime {
     from: InitialModule,
     options?: InternalModuleOptions,
   ): NodeRequire {
-    // 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?.[OUTSIDE_JEST_VM_RESOLVE_OPTION] &&
+        options?.isInternalModule
+      ) {
+        return createOutsideJestVmPath(resolved);
+      }
+      return resolved;
+    };
     resolve.paths = (moduleName: string) =>
       this._requireResolvePaths(from.filename, moduleName);