fix(@angular/build): allow overriding Vitest coverage reportsDirectory option

The Vitest `reportsDirectory` coverage option can now be customized via a `runnerConfig` configuration file.

Author: clydin

packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts

@@ -154,7 +154,11 @@ export async function createVitestConfigPlugin(
 
       return {
         test: {
-          coverage: await generateCoverageOption(options.coverage, projectName),
+          coverage: await generateCoverageOption(
+            options.coverage,
+            testConfig?.coverage,
+            projectName,
+          ),
           // eslint-disable-next-line @typescript-eslint/no-explicit-any
           ...(reporters ? ({ reporters } as any) : {}),
           projects: [projectConfig],
@@ -303,40 +307,44 @@ export function createVitestPlugins(pluginOptions: PluginOptions): VitestPlugins
 }
 
 async function generateCoverageOption(
-  coverage: NormalizedUnitTestBuilderOptions['coverage'],
+  optionsCoverage: NormalizedUnitTestBuilderOptions['coverage'],
+  configCoverage: VitestCoverageOption | undefined,
   projectName: string,
 ): Promise<VitestCoverageOption> {
   let defaultExcludes: string[] = [];
-  if (coverage.exclude) {
+  if (optionsCoverage.exclude) {
     try {
       const vitestConfig = await import('vitest/config');
       defaultExcludes = vitestConfig.coverageConfigDefaults.exclude;
     } catch {}
   }
 
   return {
-    enabled: coverage.enabled,
     excludeAfterRemap: true,
+    reportsDirectory:
+      configCoverage?.reportsDirectory ?? toPosixPath(path.join('coverage', projectName)),
+    ...(optionsCoverage.enabled !== undefined ? { enabled: optionsCoverage.enabled } : {}),
     // Vitest performs a pre-check and a post-check for sourcemaps.
     // The pre-check uses the bundled files, so specific bundled entry points and chunks need to be included.
     // The post-check uses the original source files, so the user's include is used.
-    ...(coverage.include ? { include: ['spec-*.js', 'chunk-*.js', ...coverage.include] } : {}),
-    reportsDirectory: toPosixPath(path.join('coverage', projectName)),
-    thresholds: coverage.thresholds,
-    watermarks: coverage.watermarks,
+    ...(optionsCoverage.include
+      ? { include: ['spec-*.js', 'chunk-*.js', ...optionsCoverage.include] }
+      : {}),
+    thresholds: optionsCoverage.thresholds,
+    watermarks: optionsCoverage.watermarks,
     // Special handling for `exclude`/`reporters` due to an undefined value causing upstream failures
-    ...(coverage.exclude
+    ...(optionsCoverage.exclude
       ? {
           exclude: [
             // Augment the default exclude https://vitest.dev/config/#coverage-exclude
             // with the user defined exclusions
-            ...coverage.exclude,
+            ...optionsCoverage.exclude,
             ...defaultExcludes,
           ],
         }
       : {}),
-    ...(coverage.reporters
-      ? ({ reporter: coverage.reporters } satisfies VitestCoverageOption)
+    ...(optionsCoverage.reporters
+      ? ({ reporter: optionsCoverage.reporters } satisfies VitestCoverageOption)
       : {}),
   };
 }

packages/angular/build/src/builders/unit-test/tests/behavior/runner-config-vitest_spec.ts

@@ -42,6 +42,56 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
       harness.expectFile('vitest-results.xml').toExist();
     });
 
+    it('should use custom reportsDirectory defined in runnerConfig file', async () => {
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+        runnerConfig: 'vitest.config.ts',
+        coverage: true,
+      });
+
+      harness.writeFile(
+        'vitest.config.ts',
+        `
+        import { defineConfig } from 'vitest/config';
+        export default defineConfig({
+          test: {
+            coverage: {
+              reportsDirectory: './custom-coverage-reports',
+            },
+          },
+        });
+        `,
+      );
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeTrue();
+      harness.expectFile('custom-coverage-reports/coverage-final.json').toExist();
+    });
+
+    it('should use default reportsDirectory when not defined in runnerConfig file', async () => {
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+        coverage: true,
+        runnerConfig: 'vitest.config.ts',
+      });
+
+      harness.writeFile(
+        'vitest.config.ts',
+        `
+        import { defineConfig } from 'vitest/config';
+        export default defineConfig({
+          test: {
+            coverage: {},
+          },
+        });
+        `,
+      );
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeTrue();
+      harness.expectFile('coverage/test/coverage-final.json').toExist();
+    });
+
     it('should exclude test files based on runnerConfig file', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,