fix(@angular/build): trigger test re-run on non-spec file changes in watch mode

[maruthang]

PR Checklist

• The commit message follows our guidelines: https://github.com/angular/angular-cli/blob/main/CONTRIBUTING.md#-commit-message-guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

• Bugfix

What is the current behavior?

In watch mode, the unit-test builder only re-runs tests when .spec.ts files change. Changes to non-test files (services, components, etc.) are ignored, even though tests depend on them.

Issue Number: #32159

What is the new behavior?

When non-test files change during watch mode, Vitest's module graph is queried to find dependent test specifications, which are then included in the re-run set. This ensures that changes to any source file trigger the relevant tests.

Does this PR introduce a breaking change?

• Yes
• No

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[gemini-code-assist]

Code Review

This pull request updates the Vitest executor to ensure that changes to non-test files, such as components or services, trigger re-runs of their dependent test specifications by querying Vitest's module graph. A new test case verifies this behavior in watch mode. The reviewer suggested refactoring the logic in executor.ts to consolidate multiple loops into a single, more efficient loop that uses a Set for deduplication.

[gemini-code-assist]

The logic for collecting specs to re-run is spread across multiple loops and intermediate collections (modifiedSourceFiles, modifiedNonTestFiles). This could be simplified and made more efficient by processing each modified file in a single loop. This would also naturally handle deduplication of specs if a Set is used.

Consider refactoring the logic from lines 145-190 to something like this:

const specsToRerun = new Set<string>();
for (const modifiedFile of [...buildResult.modified, ...buildResult.added]) {
  const absoluteOutputFile = this.normalizePath(path.join(this.options.workspaceRoot, modifiedFile));
  vitest.invalidateFile(absoluteOutputFile);

  const source = this.entryPointToTestFile.get(modifiedFile);
  if (source) {
    // This is a test file
    vitest.invalidateFile(source);
    const specs = vitest.getModuleSpecifications(source);
    if (specs) {
      specs.forEach(spec => specsToRerun.add(spec));
    }
  } else {
    // This is a non-test file
    const specs = vitest.getModuleSpecifications(absoluteOutputFile);
    if (specs) {
      this.debugLog(
        DebugLogLevel.Verbose,
        `Found ${specs.length} dependent test specification(s) for non-test file '${absoluteOutputFile}'.`,
      );
      specs.forEach(spec => specsToRerun.add(spec));
    }
  }
}

if (specsToRerun.size > 0) {
  const specsToRerunArr = [...specsToRerun];
  this.debugLog(DebugLogLevel.Info, `Re-running ${specsToRerunArr.length} test specifications.`);
  this.debugLog(DebugLogLevel.Verbose, 'Specs to rerun:', specsToRerunArr);
  testResults = await vitest.rerunTestSpecifications(specsToRerunArr);
}