refactor(@schematics/angular): transform flushMicrotasks

Author: yjaaidi

packages/schematics/angular/refactor/jasmine-vitest/test-file-transformer.ts

@@ -15,6 +15,7 @@
 
 import ts from '../../third_party/github.com/Microsoft/TypeScript/lib/typescript';
 import { transformFakeAsyncFlush } from './transformers/fake-async-flush';
+import { transformFakeAsyncFlushMicrotasks } from './transformers/fake-async-flush-microtasks';
 import { transformFakeAsyncTest } from './transformers/fake-async-test';
 import { transformFakeAsyncTick } from './transformers/fake-async-tick';
 import {
@@ -131,6 +132,7 @@ const callExpressionTransformers = [
   transformFakeAsyncTest,
   transformFakeAsyncTick,
   transformFakeAsyncFlush,
+  transformFakeAsyncFlushMicrotasks,
 
   // **Stage 3: Global Functions & Cleanup**
   // These handle global Jasmine functions and catch-alls for unsupported APIs.

packages/schematics/angular/refactor/jasmine-vitest/transformers/fake-async-flush-microtasks.ts

@@ -0,0 +1,42 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import ts from '../../../third_party/github.com/Microsoft/TypeScript/lib/typescript';
+import { isNamedImportFrom } from '../utils/ast-helpers';
+import { ANGULAR_CORE_TESTING } from '../utils/constants';
+import { RefactorContext, addImportSpecifierRemoval } from '../utils/refactor-context';
+
+export function transformFakeAsyncFlushMicrotasks(node: ts.Node, ctx: RefactorContext): ts.Node {
+  if (
+    ts.isCallExpression(node) &&
+    ts.isIdentifier(node.expression) &&
+    node.expression.text === 'flushMicrotasks' &&
+    isNamedImportFrom(ctx.sourceFile, 'flushMicrotasks', ANGULAR_CORE_TESTING)
+  ) {
+    ctx.reporter.reportTransformation(
+      ctx.sourceFile,
+      node,
+      `Transformed \`flushMicrotasks\` to \`await vi.advanceTimersByTimeAsync(0)\`.`,
+    );
+
+    addImportSpecifierRemoval(ctx, 'flushMicrotasks', ANGULAR_CORE_TESTING);
+
+    return ts.factory.createAwaitExpression(
+      ts.factory.createCallExpression(
+        ts.factory.createPropertyAccessExpression(
+          ts.factory.createIdentifier('vi'),
+          'advanceTimersByTimeAsync',
+        ),
+        undefined,
+        [ts.factory.createNumericLiteral(0)],
+      ),
+    );
+  }
+
+  return node;
+}

packages/schematics/angular/refactor/jasmine-vitest/transformers/fake-async-flush-microtasks_spec.ts

@@ -0,0 +1,43 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import { expectTransformation } from '../test-helpers';
+
+describe('transformFakeAsyncFlushMicrotasks', () => {
+  const testCases = [
+    {
+      description: 'should replace `flushMicrotasks` with `await vi.advanceTimersByTimeAsync(0)`',
+      input: `
+          import { flushMicrotasks } from '@angular/core/testing';
+          
+          flushMicrotasks();
+        `,
+      expected: `await vi.advanceTimersByTimeAsync(0);`,
+    },
+    {
+      description:
+        'should not replace `flushMicrotasks` if not imported from `@angular/core/testing`',
+      input: `
+          import { flushMicrotasks } from './my-flush-microtasks';
+          
+          flushMicrotasks();
+        `,
+      expected: `
+          import { flushMicrotasks } from './my-flush-microtasks';
+          
+          flushMicrotasks();
+        `,
+    },
+  ];
+
+  testCases.forEach(({ description, input, expected }) => {
+    it(description, async () => {
+      await expectTransformation(input, expected);
+    });
+  });
+});