chore: make requiring from outside the Jest VM easier w/ a Babel plug…

…in (#10824)

CHANGELOG.md

@@ -20,6 +20,7 @@
 
 - `[*]` [**BREAKING**] Only support Node LTS releases and Node 15 ([#10685](https://github.com/facebook/jest/pull/10685))
 - `[*]` [**BREAKING**] Add `exports` field to all `package.json`s ([#9921](https://github.com/facebook/jest/pull/9921))
+- `[*]` Make it easier for Jest's packages to use the VM escape hatch ([#10824](https://github.com/facebook/jest/pull/10824))
 - `[jest-config]` [**BREAKING**] Remove `enabledTestsMap` config, use `filter` instead ([#10787](https://github.com/facebook/jest/pull/10787))
 - `[jest-resolve]` [**BREAKING**] Migrate to ESM ([#10688](https://github.com/facebook/jest/pull/10688))
 

babel.config.js

@@ -56,6 +56,7 @@ module.exports = {
     ['@babel/plugin-transform-modules-commonjs', {allowTopLevelThis: true}],
     '@babel/plugin-transform-strict-mode',
     '@babel/plugin-proposal-class-properties',
+    require.resolve('./scripts/babel-plugin-jest-require-outside-vm'),
   ],
   presets: [
     [

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

@@ -44,7 +44,7 @@ describe('Runtime require.resolve', () => {
     );
   });
 
-  describe('with the OUTSIDE_JEST_VM_RESOLVE_OPTION', () => {
+  describe('with the jest-resolve-outside-vm-option', () => {
     it('forwards to the real Node require in an internal context', async () => {
       const runtime = await createRuntime(__filename);
       const module = runtime.requireInternalModule(

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

@@ -8,7 +8,7 @@
 'use strict';
 
 const resolved = require.resolve('./create_require_module', {
-  [Symbol.for('OUTSIDE_JEST_VM_RESOLVE_OPTION')]: true,
+  [Symbol.for('jest-resolve-outside-vm-option')]: true,
 });
 if (typeof resolved !== 'string') {
   throw new Error('require.resolve not spec-compliant: must return a string');

packages/jest-runtime/src/index.ts

@@ -92,11 +92,11 @@ const defaultTransformOptions: InternalModuleOptions = {
 type InitialModule = Omit<Module, 'require' | 'parent' | 'paths'>;
 type ModuleRegistry = Map<string, InitialModule | Module>;
 
-const OUTSIDE_JEST_VM_RESOLVE_OPTION = Symbol.for(
-  'OUTSIDE_JEST_VM_RESOLVE_OPTION',
+const JEST_RESOLVE_OUTSIDE_VM_OPTION = Symbol.for(
+  'jest-resolve-outside-vm-option',
 );
 type ResolveOptions = Parameters<typeof require.resolve>[1] & {
-  [OUTSIDE_JEST_VM_RESOLVE_OPTION]?: true;
+  [JEST_RESOLVE_OUTSIDE_VM_OPTION]?: true;
 };
 
 type StringMap = Map<string, string>;
@@ -1402,7 +1402,7 @@ export default class Runtime {
         resolveOptions,
       );
       if (
-        resolveOptions?.[OUTSIDE_JEST_VM_RESOLVE_OPTION] &&
+        resolveOptions?.[JEST_RESOLVE_OUTSIDE_VM_OPTION] &&
         options?.isInternalModule
       ) {
         return createOutsideJestVmPath(resolved);

scripts/babel-plugin-jest-require-outside-vm.js

@@ -0,0 +1,53 @@
+/**
+ * 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 assert = require('assert');
+
+/*
+Replace
+
+requireOutside('package')
+
+with
+
+require(require.resolve('package', {
+  [Symbol.for('jest-resolve-outside-vm-option')]: true,
+}));
+*/
+
+const REQUIRE_OUTSIDE_FUNCTION_NAME = 'requireOutside';
+
+module.exports = ({template, types: t}) => {
+  const replacement = template(`
+    require(require.resolve(IMPORT_PATH, {
+      [(global['jest-symbol-do-not-touch'] || global.Symbol).for('jest-resolve-outside-vm-option')]: true,
+    }));
+  `);
+  return {
+    name: 'jest-require-outside-vm',
+    visitor: {
+      CallExpression(path) {
+        const {callee, arguments: args} = path.node;
+        if (
+          t.isIdentifier(callee) &&
+          callee.name === REQUIRE_OUTSIDE_FUNCTION_NAME &&
+          !path.scope.hasBinding(REQUIRE_OUTSIDE_FUNCTION_NAME)
+        ) {
+          assert.strictEqual(
+            args.length,
+            1,
+            'requireOutside must be called with exactly one argument',
+          );
+          const importPath = args[0];
+          path.replaceWith(replacement({IMPORT_PATH: importPath}));
+        }
+      },
+    },
+  };
+};