fix(@angular/build): allow vitest-based unit testing to use watch option

When using the `application` build system with the experimental `unit-test` vitest support, the `watch` option will now be passed through to the underlying test runner. This allows vitest to be used for watch-based test development. Incremental test file updates from the build system are also enabled in watch mode as well to remove the need to rewrite all output files on a rebuild. (cherry picked from commit bfcee38)

Author: clydin

packages/angular/build/src/builders/unit-test/builder.ts

@@ -100,6 +100,7 @@ export async function* execute(
  const buildOptions: ApplicationBuilderInternalOptions = {
  ...buildTargetOptions,
  watch: normalizedOptions.watch,
+ incrementalResults: normalizedOptions.watch,
  outputPath,
  index: false,
  browser: undefined,
@@ -171,44 +172,52 @@ export async function* execute(
  };
  }
 
- for await (const result of buildApplicationInternal(buildOptions, context, extensions)) {
- if (result.kind === ResultKind.Failure) {
- continue;
- } else if (result.kind !== ResultKind.Full) {
- assert.fail('A full build result is required from the application builder.');
- }
-
- assert(result.files, 'Builder did not provide result files.');
-
- await writeTestFiles(result.files, outputPath);
-
- const setupFiles = ['init-testbed.js'];
- if (buildTargetOptions?.polyfills?.length) {
- setupFiles.push('polyfills.js');
- }
+ const setupFiles = ['init-testbed.js'];
+ if (buildTargetOptions?.polyfills?.length) {
+ setupFiles.push('polyfills.js');
+ }
 
- instance ??= await startVitest('test', undefined /* cliFilters */, undefined /* options */, {
- test: {
- root: outputPath,
- setupFiles,
- // Use `jsdom` if no browsers are explicitly configured.
- // `node` is effectively no "environment" and the default.
- environment: browser ? 'node' : 'jsdom',
- watch: normalizedOptions.watch,
- browser,
- reporters: normalizedOptions.reporters ?? ['default'],
- coverage: {
- enabled: normalizedOptions.codeCoverage,
- exclude: normalizedOptions.codeCoverageExclude,
- excludeAfterRemap: true,
+ try {
+ for await (const result of buildApplicationInternal(buildOptions, context, extensions)) {
+ if (result.kind === ResultKind.Failure) {
+ continue;
+ } else if (result.kind !== ResultKind.Full && result.kind !== ResultKind.Incremental) {
+ assert.fail(
+ 'A full and/or incremental build result is required from the application builder.',
+ );
+ }
+ assert(result.files, 'Builder did not provide result files.');
+
+ await writeTestFiles(result.files, outputPath);
+
+ instance ??= await startVitest('test', undefined /* cliFilters */, undefined /* options */, {
+ test: {
+ root: outputPath,
+ setupFiles,
+ // Use `jsdom` if no browsers are explicitly configured.
+ // `node` is effectively no "environment" and the default.
+ environment: browser ? 'node' : 'jsdom',
+ watch: normalizedOptions.watch,
+ browser,
+ reporters: normalizedOptions.reporters ?? ['default'],
+ coverage: {
+ enabled: normalizedOptions.codeCoverage,
+ exclude: normalizedOptions.codeCoverageExclude,
+ excludeAfterRemap: true,
+ },
  },
- },
- });
+ });
 
- // Check if all the tests pass to calculate the result
- const testModules = instance.state.getTestModules();
+  // Check if all the tests pass to calculate the result
+  const testModules = instance.state.getTestModules();
 
- yield { success: testModules.every((testModule) => testModule.ok()) };
+ yield { success: testModules.every((testModule) => testModule.ok()) };
+ }
+ } finally {
+ if (normalizedOptions.watch) {
+ // Vitest will automatically close if not using watch mode
+ await instance?.close();
+ }
  }
 }
 

packages/angular/build/src/builders/unit-test/options.ts

@@ -32,7 +32,8 @@ export async function normalizeOptions(
  const buildTargetSpecifier = options.buildTarget ?? `::development`;
  const buildTarget = targetFromTargetString(buildTargetSpecifier, projectName, 'build');
 
- const { codeCoverage, codeCoverageExclude, tsConfig, runner, reporters, browsers } = options;
+ const { codeCoverage, codeCoverageExclude, tsConfig, runner, reporters, browsers, watch } =
+ options;
 
  return {
  // Project/workspace information
@@ -50,8 +51,7 @@ export async function normalizeOptions(
  tsConfig,
  reporters,
  browsers,
- // TODO: Implement watch support
- watch: false,
+ watch,
  };
 }