refactor(@angular/build): normalize unit test coverage options for consistency

Previously, the unit test builder's `coverage` option was conditional. It was only defined if `coverage: true` was set, and it consolidated several top-level `coverage*` properties from the schema. This required downstream consumers, like the Karma and Vitest executors, to handle a potentially undefined object and led to complex and sometimes incorrect option merging, especially in the Vitest runner.

This commit refactors the option normalization logic to ensure the `coverage` object is *always* defined. A new `enabled` flag, controlled by the main `coverage` option, is now part of this object.

(cherry picked from commit 4cb985c)

Author: clydin

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

@@ -96,22 +96,21 @@ export async function normalizeOptions(
     exclude: options.exclude,
     filter,
     runnerName: runner ?? 'vitest',
-    coverage: options.coverage
-      ? {
-          exclude: options.coverageExclude,
-          include: options.coverageInclude,
-          reporters: normalizeReporterOption(options.coverageReporters),
-          thresholds: options.coverageThresholds,
-          // The schema generation tool doesn't support tuple types for items, but the schema validation
-          // does ensure that the array has exactly two numbers.
-          watermarks: options.coverageWatermarks as {
-            statements?: [number, number];
-            branches?: [number, number];
-            functions?: [number, number];
-            lines?: [number, number];
-          },
-        }
-      : undefined,
+    coverage: {
+      enabled: options.coverage,
+      exclude: options.coverageExclude,
+      include: options.coverageInclude,
+      reporters: normalizeReporterOption(options.coverageReporters),
+      thresholds: options.coverageThresholds,
+      // The schema generation tool doesn't support tuple types for items, but the schema validation
+      // does ensure that the array has exactly two numbers.
+      watermarks: options.coverageWatermarks as {
+        statements?: [number, number];
+        branches?: [number, number];
+        functions?: [number, number];
+        lines?: [number, number];
+      },
+    },
     tsConfig,
     buildProgress: progress,
     reporters: normalizeReporterOption(options.reporters),

packages/angular/build/src/builders/unit-test/runners/karma/executor.ts

@@ -87,8 +87,8 @@ export class KarmaExecutor implements TestExecutor {
       poll: buildTargetOptions.poll,
       preserveSymlinks: buildTargetOptions.preserveSymlinks,
       browsers: unitTestOptions.browsers?.join(','),
-      codeCoverage: !!unitTestOptions.coverage,
-      codeCoverageExclude: unitTestOptions.coverage?.exclude,
+      codeCoverage: unitTestOptions.coverage.enabled,
+      codeCoverageExclude: unitTestOptions.coverage.exclude,
       fileReplacements: buildTargetOptions.fileReplacements,
       reporters: unitTestOptions.reporters?.map((reporter) => {
         // Karma only supports string reporters.
@@ -123,7 +123,7 @@ export class KarmaExecutor implements TestExecutor {
         }
 
         // Add coverage options
-        if (unitTestOptions.coverage) {
+        if (unitTestOptions.coverage.enabled) {
           const { thresholds, watermarks } = unitTestOptions.coverage;
           // eslint-disable-next-line @typescript-eslint/no-explicit-any
           const coverageReporter = ((options as any).coverageReporter ??= {});

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

@@ -242,12 +242,6 @@ async function generateCoverageOption(
   coverage: NormalizedUnitTestBuilderOptions['coverage'],
   projectName: string,
 ): Promise<VitestCoverageOption> {
-  if (!coverage) {
-    return {
-      enabled: false,
-    };
-  }
-
   let defaultExcludes: string[] = [];
   if (coverage.exclude) {
     try {
@@ -257,7 +251,7 @@ async function generateCoverageOption(
   }
 
   return {
-    enabled: true,
+    enabled: coverage.enabled,
     excludeAfterRemap: true,
     include: coverage.include,
     reportsDirectory: toPosixPath(path.join('coverage', projectName)),

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

@@ -32,7 +32,7 @@ const VitestTestRunner: TestRunner = {
       checker.check('jsdom');
     }
 
-    if (options.coverage) {
+    if (options.coverage.enabled) {
       checker.check('@vitest/coverage-v8');
     }