test_runner: deprecate legacy mock.module options

Emit runtime deprecation warnings for defaultExport and namedExports

when mock.module() is called with legacy option names.

Switch output fixtures to options.exports to keep output snapshots

stable and update the TypeScript coverage snapshot percentage.

Refs: #58443

Author: Han5991

lib/internal/test_runner/mock/mock.js

@@ -61,6 +61,8 @@ const kSupportedFormats = [
   'module',
 ];
 let sharedModuleState;
+let warnedLegacyDefaultExport;
+let warnedLegacyNamedExports;
 const {
   hooks: mockHooks,
   mocks,
@@ -828,10 +830,12 @@ function normalizeModuleMockOptions(options) {
 
   if ('namedExports' in options) {
     validateObject(options.namedExports, 'options.namedExports');
+    emitLegacyMockOptionWarning('namedExports');
     copyOwnProperties(options.namedExports, moduleExports);
   }
 
   if ('defaultExport' in options) {
+    emitLegacyMockOptionWarning('defaultExport');
     moduleExports.default = options.defaultExport;
   }
 
@@ -858,6 +862,33 @@ function normalizeModuleMockOptions(options) {
   };
 }
 
+function emitLegacyMockOptionWarning(option) {
+  switch (option) {
+    case 'defaultExport':
+      if (warnedLegacyDefaultExport === true) {
+        return;
+      }
+      warnedLegacyDefaultExport = true;
+      process.emitWarning(
+        'mock.module(): options.defaultExport is deprecated. ' +
+        'Use options.exports.default instead.',
+        'DeprecationWarning',
+      );
+      break;
+    case 'namedExports':
+      if (warnedLegacyNamedExports === true) {
+        return;
+      }
+      warnedLegacyNamedExports = true;
+      process.emitWarning(
+        'mock.module(): options.namedExports is deprecated. ' +
+        'Use options.exports instead.',
+        'DeprecationWarning',
+      );
+      break;
+  }
+}
+
 function copyOwnProperties(from, to) {
   const keys = ObjectKeys(from);
 

test/fixtures/test-runner/output/coverage-with-mock.mjs

@@ -2,7 +2,7 @@ import { describe, it, mock } from 'node:test';
 
 describe('module test with mock', async () => {
   mock.module('../coverage-with-mock/sum.js', {
-    namedExports: {
+    exports: {
       sum: (a, b) => 1,
       getData: () => ({}),
     },

test/fixtures/test-runner/output/typescript-coverage.mts

@@ -10,8 +10,10 @@ describe('foo', { concurrency: true }, () => {
             .then(({ default: _, ...rest }) => rest);
 
         mock.module('../coverage/bar.mts', {
-            defaultExport: barMock,
-            namedExports: barNamedExports,
+            exports: {
+                ...barNamedExports,
+                default: barMock,
+            },
         });
 
         ({ foo } = await import('../coverage/foo.mts'));

test/fixtures/test-runner/output/typescript-coverage.snapshot

@@ -34,6 +34,6 @@ ok 1 - foo
 #    output                   |        |          |         |
 #     typescript-coverage.mts | 100.00 |   100.00 |  100.00 |
 # ----------------------------------------------------------------------------
-# all files                   |  93.55 |   100.00 |   85.71 |
+# all files                   |  93.94 |   100.00 |   85.71 |
 # ----------------------------------------------------------------------------
 # end of coverage report