fix: enforce import assertions when importing JSON in ESM (#12755)

Author: SimenB

CHANGELOG.md

@@ -14,12 +14,13 @@
 
 ### Fixes
 
-- `[jest-environment-node]` fix non-configurable globals ([#13687](https://github.com/facebook/jest/pull/13687))
+- `[jest-environment-node]` Fix non-configurable globals ([#13687](https://github.com/facebook/jest/pull/13687))
 - `[@jest/expect-utils]` `toMatchObject` should handle `Symbol` properties ([#13639](https://github.com/facebook/jest/pull/13639))
-- `[jest-mock]` fix mockReset and resetAllMocks undefined return ([#13692](https://github.com/facebook/jest/pull/13692))
+- `[jest-mock]` Fix `mockReset` and `resetAllMocks` `undefined` return value([#13692](https://github.com/facebook/jest/pull/13692))
 - `[jest-resolve]` Add global paths to `require.resolve.paths` ([#13633](https://github.com/facebook/jest/pull/13633))
-- `[jest-runtime]` Support Wasm files that import JS resources ([#13608](https://github.com/facebook/jest/pull/13608))
-- `[jest-runtime]` Using the scriptTransformer cache in jest-runner ([#13735](https://github.com/facebook/jest/pull/13735))
+- `[jest-runtime]` Support WASM files that import JS resources ([#13608](https://github.com/facebook/jest/pull/13608))
+- `[jest-runtime]` Use the `scriptTransformer` cache in `jest-runner` ([#13735](https://github.com/facebook/jest/pull/13735))
+- `[jest-runtime]` Enforce import assertions when importing JSON in ESM ([#12755](https://github.com/facebook/jest/pull/12755))
 - `[jest-snapshot]` Make sure to import `babel` outside of the sandbox ([#13694](https://github.com/facebook/jest/pull/13694))
 - `[jest-transform]` Ensure the correct configuration is passed to preprocessors specified multiple times in the `transform` option ([#13770](https://github.com/facebook/jest/pull/13770))
 

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

@@ -1,5 +1,13 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`on node <16.12.0 does not enforce import assertions 1`] = `
+"Test Suites: 1 passed, 1 total
+Tests:       2 passed, 2 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites matching /native-esm-missing-import-assertions.test/i."
+`;
+
 exports[`on node >=16.9.0 support re-exports from CJS of dual packages 1`] = `
 "Test Suites: 1 passed, 1 total
 Tests:       1 passed, 1 total
@@ -8,6 +16,14 @@ Time:        <<REPLACED>>
 Ran all test suites matching /native-esm-deep-cjs-reexport.test.js/i."
 `;
 
+exports[`on node >=16.12.0 supports import assertions 1`] = `
+"Test Suites: 1 passed, 1 total
+Tests:       2 passed, 2 total
+Snapshots:   0 total
+Time:        <<REPLACED>>
+Ran all test suites matching /native-esm-import-assertions.test/i."
+`;
+
 exports[`runs WebAssembly (Wasm) test with native ESM 1`] = `
 "Test Suites: 1 passed, 1 total
 Tests:       6 passed, 6 total

e2e/__tests__/nativeEsm.test.ts

@@ -79,3 +79,66 @@ test('runs WebAssembly (Wasm) test with native ESM', () => {
   expect(stdout).toBe('');
   expect(exitCode).toBe(0);
 });
+
+// version where `vm` API gets `import assertions`
+onNodeVersions('>=16.12.0', () => {
+  test('enforces import assertions', () => {
+    const {exitCode, stderr, stdout} = runJest(
+      DIR,
+      ['native-esm-missing-import-assertions.test'],
+      {nodeOptions: '--experimental-vm-modules --no-warnings'},
+    );
+
+    const {rest} = extractSummary(stderr);
+
+    expect(rest).toContain(
+      'package.json" needs an import assertion of type "json"',
+    );
+    expect(stdout).toBe('');
+    expect(exitCode).toBe(1);
+  });
+
+  test('supports import assertions', () => {
+    const {exitCode, stderr, stdout} = runJest(
+      DIR,
+      ['native-esm-import-assertions.test'],
+      {nodeOptions: '--experimental-vm-modules --no-warnings'},
+    );
+
+    const {summary} = extractSummary(stderr);
+
+    expect(summary).toMatchSnapshot();
+    expect(stdout).toBe('');
+    expect(exitCode).toBe(0);
+  });
+});
+
+onNodeVersions('<16.12.0', () => {
+  test('does not enforce import assertions', () => {
+    const {exitCode, stderr, stdout} = runJest(
+      DIR,
+      ['native-esm-missing-import-assertions.test'],
+      {nodeOptions: '--experimental-vm-modules --no-warnings'},
+    );
+
+    const {summary} = extractSummary(stderr);
+
+    expect(summary).toMatchSnapshot();
+    expect(stdout).toBe('');
+    expect(exitCode).toBe(0);
+  });
+
+  test('syntax error for import assertions', () => {
+    const {exitCode, stderr, stdout} = runJest(
+      DIR,
+      ['native-esm-import-assertions.test'],
+      {nodeOptions: '--experimental-vm-modules --no-warnings'},
+    );
+
+    const {rest} = extractSummary(stderr);
+
+    expect(rest).toContain('SyntaxError: Unexpected identifier');
+    expect(stdout).toBe('');
+    expect(exitCode).toBe(1);
+  });
+});

e2e/native-esm/__tests__/native-esm-import-assertions.test.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.
+ */
+
+import json from '../package.json' assert {type: 'json'};
+
+test('supports static import', () => {
+  expect(json).toHaveProperty('jest.testEnvironment', 'node');
+});
+
+test('supports dynamic import', async () => {
+  const {default: json} = await import('../package.json', {
+    assert: {type: 'json'},
+  });
+  expect(json).toHaveProperty('jest.testEnvironment', 'node');
+});

e2e/native-esm/__tests__/native-esm-missing-import-assertions.test.js

@@ -0,0 +1,17 @@
+/**
+ * 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 json from '../package.json';
+
+test('supports static import', () => {
+  expect(json).toHaveProperty('jest.testEnvironment', 'node');
+});
+
+test('supports dynamic import', async () => {
+  const {default: json} = await import('../package.json');
+  expect(json).toHaveProperty('jest.testEnvironment', 'node');
+});

packages/jest-runtime/package.json

@@ -37,13 +37,15 @@
     "jest-resolve": "workspace:^",
     "jest-snapshot": "workspace:^",
     "jest-util": "workspace:^",
+    "semver": "^7.3.5",
     "slash": "^3.0.0",
     "strip-bom": "^4.0.0"
   },
   "devDependencies": {
     "@jest/test-utils": "workspace:^",
     "@types/glob": "^7.1.1",
     "@types/graceful-fs": "^4.1.3",
+    "@types/semver": "^7.1.0",
     "jest-environment-node": "workspace:^"
   },
   "engines": {