feat: ESM data uri import and mock

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

@@ -41,7 +41,7 @@ exports[`moduleNameMapper wrong array configuration 1`] = `
       12 | module.exports = () => 'test';
       13 |
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:568:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:572:17)
       at Object.require (index.js:10:1)"
 `;
 
@@ -70,6 +70,6 @@ exports[`moduleNameMapper wrong configuration 1`] = `
       12 | module.exports = () => 'test';
       13 |
 
-      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:568:17)
+      at createNoMappedModuleFoundError (../../packages/jest-resolve/build/resolver.js:572:17)
       at Object.require (index.js:10:1)"
 `;

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

@@ -2,7 +2,7 @@
 
 exports[`on node >=12.16.0 runs test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
-Tests:       21 passed, 21 total
+Tests:       25 passed, 25 total
 Snapshots:   0 total
 Time:        <<REPLACED>>
 Ran all test suites matching /native-esm.test.js/i."

e2e/native-esm/__tests__/native-esm.test.js

@@ -5,23 +5,23 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import dns from 'dns';
+import {jest as jestObject} from '@jest/globals'
+import dns from 'dns'
 // the point here is that it's the node core module
 // eslint-disable-next-line no-restricted-imports
-import {readFileSync} from 'fs';
-import {createRequire} from 'module';
-import prefixDns from 'node:dns';
-import {dirname, resolve} from 'path';
-import {fileURLToPath} from 'url';
-import {jest as jestObject} from '@jest/globals';
-import staticImportedStatefulFromCjs from '../fromCjs.mjs';
-import {double} from '../index';
-import defaultFromCjs, {half, namedFunction} from '../namedExport.cjs';
-import {bag} from '../namespaceExport.js';
+import {readFileSync} from 'fs'
+import {createRequire} from 'module'
+import prefixDns from 'node:dns'
+import {dirname, resolve} from 'path'
+import {fileURLToPath} from 'url'
+import staticImportedStatefulFromCjs from '../fromCjs.mjs'
+import {double} from '../index'
+import defaultFromCjs, {half, namedFunction} from '../namedExport.cjs'
+import {bag} from '../namespaceExport.js'
 /* eslint-disable import/no-duplicates */
-import staticImportedStateful from '../stateful.mjs';
-import staticImportedStatefulWithQuery from '../stateful.mjs?query=1';
-import staticImportedStatefulWithAnotherQuery from '../stateful.mjs?query=2';
+import staticImportedStateful from '../stateful.mjs'
+import staticImportedStatefulWithQuery from '../stateful.mjs?query=1'
+import staticImportedStatefulWithAnotherQuery from '../stateful.mjs?query=2'
 /* eslint-enable import/no-duplicates */
 
 test('should have correct import.meta', () => {
@@ -195,3 +195,46 @@ test('can mock module', async () => {
 test('supports imports using "node:" prefix', () => {
   expect(dns).toBe(prefixDns);
 });
+
+test('supports imports from "data:text/javascript;charset=utf-8" URI', async () => {
+  const code = 'export const something = "some value"';
+  const importedEncoded = await import(
+    `data:text/javascript;charset=utf-8,${encodeURIComponent(code)}`
+  );
+  expect(importedEncoded.something).toBe('some value');
+});
+
+test('supports imports from "data:text/javascript;base64" URI', async () => {
+  const code = 'export const something = "some value"';
+  const importedBase64 = await import(
+    `data:text/javascript;base64,${btoa(code)}`
+  );
+  expect(importedBase64.something).toBe('some value');
+});
+
+test('imports from "data:" URI is properly cached', async () => {
+  const code =
+    'export const wrapper = {value: 123}\nexport const set = (value) => wrapper.value = value';
+  const data1 = await import(
+    `data:text/javascript;charset=utf-8,${encodeURIComponent(code)}`
+  );
+  expect(data1.wrapper.value).toBe(123);
+  data1.set(234);
+  expect(data1.wrapper.value).toBe(234);
+  const data2 = await import(`data:text/javascript;base64,${btoa(code)}`);
+  expect(data2.wrapper.value).toBe(123);
+  const data3 = await import(
+    `data:text/javascript;charset=utf-8,${encodeURIComponent(code)}`
+  );
+  expect(data3.wrapper.value).toBe(234);
+});
+
+test('can mock "data:" URI module', async () => {
+  const code = 'export const something = "some value"';
+  const dataModule = `data:text/javascript;base64,${btoa(code)}`;
+  jestObject.unstable_mockModule(dataModule, () => ({foo: 'bar'}), {
+    virtual: true,
+  });
+  const mocked = await import(dataModule);
+  expect(mocked.foo).toBe('bar');
+});

packages/jest-resolve/src/resolver.ts

@@ -370,6 +370,9 @@ export default class Resolver {
     if (this.isCoreModule(moduleName)) {
       return moduleName;
     }
+    if (moduleName.startsWith('data:')) {
+      return moduleName;
+    }
     return this._isModuleResolved(from, moduleName)
       ? this.getModule(moduleName)
       : this._getVirtualMockPath(virtualMocks, from, moduleName, options);

packages/jest-runtime/src/index.ts

@@ -553,6 +553,69 @@ export default class Runtime {
       return globals;
     }
 
+    if (specifier.startsWith('data:')) {
+      if (
+        this._shouldMock(
+          referencingIdentifier,
+          specifier,
+          this._explicitShouldMockModule,
+          {conditions: this.esmConditions},
+        )
+      ) {
+        return this.importMock(referencingIdentifier, specifier, context);
+      }
+
+      const fromCache = this._esmoduleRegistry.get(specifier);
+
+      if (fromCache) {
+        return fromCache;
+      }
+
+      const match = specifier.match(
+        /^data:text\/javascript;(charset=utf-8|base64),(.*)$/,
+      );
+
+      if (!match) {
+        throw new Error('Invalid data URI');
+      }
+
+      let code = match[2];
+      if (match[1] === 'base64') {
+        code = atob(code);
+      } else if (match[1] === 'charset=utf-8') {
+        code = decodeURIComponent(code);
+      } else {
+        throw new Error('Invalid data URI encoding');
+      }
+
+      const module = new SourceTextModule(code, {
+        context,
+        identifier: specifier,
+        importModuleDynamically: async (
+          specifier: string,
+          referencingModule: VMModule,
+        ) => {
+          invariant(
+            runtimeSupportsVmModules,
+            'You need to run with a version of node that supports ES Modules in the VM API. See https://jestjs.io/docs/ecmascript-modules',
+          );
+          const module = await this.resolveModule(
+            specifier,
+            referencingModule.identifier,
+            referencingModule.context,
+          );
+
+          return this.linkAndEvaluateModule(module);
+        },
+        initializeImportMeta(meta: ImportMeta) {
+          meta.url = specifier;
+        },
+      });
+
+      this._esmoduleRegistry.set(specifier, module);
+      return module;
+    }
+
     if (specifier.startsWith('file://')) {
       specifier = fileURLToPath(specifier);
     }