feat(@angular/build): add advanced coverage options to unit-test builder

The `unit-test` builder is enhanced with several new coverage features to provide a more robust and configurable testing experience.

This change refactors the existing `codeCoverage` options to a more concise `coverage` prefix for a cleaner API. Since the builder is experimental, this is the ideal time for such an improvement.

The following new options have been added:
- `coverageAll`: Includes all files matching `coverageInclude` in the report, ensuring untested files are visible.
- `coverageInclude`: Specifies which files to include in the report, providing more accurate metrics.
- `coverageThresholds`: Allows setting minimum coverage percentages for statements, branches, functions, and lines. If thresholds are not met, the builder will exit with an error, enabling automated quality gates in CI.
- `coverageWatermarks`: Allows customization of coverage watermarks for the HTML reporter.

The Karma runner has been updated to support the `thresholds` and `watermarks` options, providing a better experience for users on that runner. Warnings remain for options that are still unsupported.

Author: clydin

goldens/public-api/angular/build/index.api.md

@@ -217,9 +217,13 @@ export type NgPackagrBuilderOptions = {
 export type UnitTestBuilderOptions = {
     browsers?: string[];
     buildTarget: string;
-    codeCoverage?: boolean;
-    codeCoverageExclude?: string[];
-    codeCoverageReporters?: SchemaCodeCoverageReporter[];
+    coverage?: boolean;
+    coverageAll?: boolean;
+    coverageExclude?: string[];
+    coverageInclude?: string[];
+    coverageReporters?: SchemaCoverageReporter[];
+    coverageThresholds?: CoverageThresholds;
+    coverageWatermarks?: CoverageWatermarks;
     debug?: boolean;
     dumpVirtualFiles?: boolean;
     exclude?: string[];

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

@@ -82,10 +82,21 @@ export async function normalizeOptions(
     exclude: options.exclude,
     filter,
     runnerName: runner,
-    codeCoverage: options.codeCoverage
+    coverage: options.coverage
       ? {
-          exclude: options.codeCoverageExclude,
-          reporters: normalizeReporterOption(options.codeCoverageReporters),
+          all: options.coverageAll,
+          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,
     tsConfig,

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

@@ -33,6 +33,18 @@ export class KarmaExecutor implements TestExecutor {
       );
     }
 
+    if (unitTestOptions.coverage?.all) {
+      context.logger.warn(
+        'The "karma" test runner does not support the "coverageAll" option. The option will be ignored.',
+      );
+    }
+
+    if (unitTestOptions.coverage?.include) {
+      context.logger.warn(
+        'The "karma" test runner does not support the "coverageInclude" option. The option will be ignored.',
+      );
+    }
+
     const buildTargetOptions = (await context.validateOptions(
       await context.getTargetOptions(unitTestOptions.buildTarget),
       await context.getBuilderNameForTarget(unitTestOptions.buildTarget),
@@ -57,8 +69,8 @@ export class KarmaExecutor implements TestExecutor {
       poll: buildTargetOptions.poll,
       preserveSymlinks: buildTargetOptions.preserveSymlinks,
       browsers: unitTestOptions.browsers?.join(','),
-      codeCoverage: !!unitTestOptions.codeCoverage,
-      codeCoverageExclude: unitTestOptions.codeCoverage?.exclude,
+      codeCoverage: !!unitTestOptions.coverage,
+      codeCoverageExclude: unitTestOptions.coverage?.exclude,
       fileReplacements: buildTargetOptions.fileReplacements,
       reporters: unitTestOptions.reporters?.map((reporter) => {
         // Karma only supports string reporters.
@@ -92,6 +104,23 @@ export class KarmaExecutor implements TestExecutor {
           options.client.args.push('--grep', filter);
         }
 
+        // Add coverage options
+        if (unitTestOptions.coverage) {
+          const { thresholds, watermarks } = unitTestOptions.coverage;
+          // eslint-disable-next-line @typescript-eslint/no-explicit-any
+          const coverageReporter = ((options as any).coverageReporter ??= {});
+
+          if (thresholds) {
+            coverageReporter.check = thresholds.perFile
+              ? { each: thresholds }
+              : { global: thresholds };
+          }
+
+          if (watermarks) {
+            coverageReporter.watermarks = watermarks;
+          }
+        }
+
         return options;
       },
     } satisfies KarmaBuilderTransformsOptions;

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

@@ -30,7 +30,7 @@ const KarmaTestRunner: TestRunner = {
       }
     }
 
-    if (options.codeCoverage) {
+    if (options.coverage) {
       checker.check('karma-coverage');
     }
 

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

@@ -126,8 +126,7 @@ export class VitestExecutor implements TestExecutor {
   }
 
   private async initializeVitest(): Promise<Vitest> {
-    const { codeCoverage, reporters, outputFile, workspaceRoot, browsers, debug, watch } =
-      this.options;
+    const { coverage, reporters, outputFile, workspaceRoot, browsers, debug, watch } = this.options;
     let vitestNodeModule;
     try {
       vitestNodeModule = await loadEsmModule<typeof import('vitest/node')>('vitest/node');
@@ -190,7 +189,7 @@ export class VitestExecutor implements TestExecutor {
         reporters: reporters ?? ['default'],
         outputFile,
         watch,
-        coverage: generateCoverageOption(codeCoverage, this.projectName),
+        coverage: generateCoverageOption(coverage, this.projectName),
         ...debugOptions,
       },
       {
@@ -206,23 +205,27 @@ export class VitestExecutor implements TestExecutor {
 }
 
 function generateCoverageOption(
-  codeCoverage: NormalizedUnitTestBuilderOptions['codeCoverage'],
+  coverage: NormalizedUnitTestBuilderOptions['coverage'],
   projectName: string,
 ): VitestCoverageOption {
-  if (!codeCoverage) {
+  if (!coverage) {
     return {
       enabled: false,
     };
   }
 
   return {
     enabled: true,
+    all: coverage.all,
     excludeAfterRemap: true,
+    include: coverage.include,
     reportsDirectory: toPosixPath(path.join('coverage', projectName)),
+    thresholds: coverage.thresholds,
+    watermarks: coverage.watermarks,
     // Special handling for `exclude`/`reporters` due to an undefined value causing upstream failures
-    ...(codeCoverage.exclude ? { exclude: codeCoverage.exclude } : {}),
-    ...(codeCoverage.reporters
-      ? ({ reporter: codeCoverage.reporters } satisfies VitestCoverageOption)
+    ...(coverage.exclude ? { exclude: coverage.exclude } : {}),
+    ...(coverage.reporters
+      ? ({ reporter: coverage.reporters } satisfies VitestCoverageOption)
       : {}),
   };
 }

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

@@ -33,7 +33,7 @@ const VitestTestRunner: TestRunner = {
       checker.check('jsdom');
     }
 
-    if (options.codeCoverage) {
+    if (options.coverage) {
       checker.check('@vitest/coverage-v8');
     }
 

packages/angular/build/src/builders/unit-test/schema.json

@@ -54,21 +54,33 @@
       "description": "Enables debugging mode for tests, allowing the use of the Node Inspector.",
       "default": false
     },
-    "codeCoverage": {
+    "coverage": {
       "type": "boolean",
-      "description": "Enables code coverage reporting for tests.",
+      "description": "Enables coverage reporting for tests.",
       "default": false
     },
-    "codeCoverageExclude": {
+    "coverageAll": {
+      "type": "boolean",
+      "description": "Includes all files that match the `coverageInclude` pattern in the coverage report, not just those touched by tests.",
+      "default": true
+    },
+    "coverageInclude": {
       "type": "array",
-      "description": "Specifies glob patterns of files to exclude from the code coverage report.",
+      "description": "Specifies glob patterns of files to include in the coverage report.",
       "items": {
         "type": "string"
       }
     },
-    "codeCoverageReporters": {
+    "coverageExclude": {
       "type": "array",
-      "description": "Specifies the reporters to use for code coverage results. Each reporter can be a string representing its name, or a tuple containing the name and an options object. Built-in reporters include 'html', 'lcov', 'lcovonly', 'text', 'text-summary', 'cobertura', 'json', and 'json-summary'.",
+      "description": "Specifies glob patterns of files to exclude from the coverage report.",
+      "items": {
+        "type": "string"
+      }
+    },
+    "coverageReporters": {
+      "type": "array",
+      "description": "Specifies the reporters to use for coverage results. Each reporter can be a string representing its name, or a tuple containing the name and an options object. Built-in reporters include 'html', 'lcov', 'lcovonly', 'text', 'text-summary', 'cobertura', 'json', and 'json-summary'.",
       "items": {
         "oneOf": [
           {
@@ -108,6 +120,68 @@
         ]
       }
     },
+    "coverageThresholds": {
+      "type": "object",
+      "description": "Specifies minimum coverage thresholds that must be met. If thresholds are not met, the builder will exit with an error.",
+      "properties": {
+        "perFile": {
+          "type": "boolean",
+          "description": "When true, thresholds are enforced for each file individually."
+        },
+        "statements": {
+          "type": "number",
+          "description": "Minimum percentage of statements covered."
+        },
+        "branches": {
+          "type": "number",
+          "description": "Minimum percentage of branches covered."
+        },
+        "functions": {
+          "type": "number",
+          "description": "Minimum percentage of functions covered."
+        },
+        "lines": {
+          "type": "number",
+          "description": "Minimum percentage of lines covered."
+        }
+      },
+      "additionalProperties": false
+    },
+    "coverageWatermarks": {
+      "type": "object",
+      "description": "Specifies coverage watermarks for the HTML reporter. These determine the color coding for high, medium, and low coverage.",
+      "properties": {
+        "statements": {
+          "type": "array",
+          "description": "The high and low watermarks for statements coverage. `[low, high]`",
+          "items": { "type": "number" },
+          "minItems": 2,
+          "maxItems": 2
+        },
+        "branches": {
+          "type": "array",
+          "description": "The high and low watermarks for branches coverage. `[low, high]`",
+          "items": { "type": "number" },
+          "minItems": 2,
+          "maxItems": 2
+        },
+        "functions": {
+          "type": "array",
+          "description": "The high and low watermarks for functions coverage. `[low, high]`",
+          "items": { "type": "number" },
+          "minItems": 2,
+          "maxItems": 2
+        },
+        "lines": {
+          "type": "array",
+          "description": "The high and low watermarks for lines coverage. `[low, high]`",
+          "items": { "type": "number" },
+          "minItems": 2,
+          "maxItems": 2
+        }
+      },
+      "additionalProperties": false
+    },
     "reporters": {
       "type": "array",
       "description": "Specifies the reporters to use during test execution. Each reporter can be a string representing its name, or a tuple containing the name and an options object. Built-in reporters include 'default', 'verbose', 'dots', 'json', 'junit', 'tap', 'tap-flat', and 'html'. You can also provide a path to a custom reporter.",

packages/angular/build/src/builders/unit-test/tests/options/code-coverage-exclude_spec.ts

@@ -15,7 +15,7 @@ import {
 } from '../setup';
 
 describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
-  describe('Option: "codeCoverageExclude"', () => {
+  describe('Option: "coverageExclude"', () => {
     beforeEach(async () => {
       setupApplicationTarget(harness);
       await harness.writeFiles({
@@ -26,7 +26,7 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
     it('should not exclude any files from coverage when not provided', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: true,
+        coverage: true,
       });
 
       const { result } = await harness.executeOnce();
@@ -38,8 +38,8 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
     it('should exclude files from coverage that match the glob pattern', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: true,
-        codeCoverageExclude: ['**/error.ts'],
+        coverage: true,
+        coverageExclude: ['**/error.ts'],
       });
 
       const { result } = await harness.executeOnce();

packages/angular/build/src/builders/unit-test/tests/options/code-coverage-reporters_spec.ts

@@ -15,16 +15,16 @@ import {
 } from '../setup';
 
 describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
-  describe('Option: "codeCoverageReporters"', () => {
+  describe('Option: "coverageReporters"', () => {
     beforeEach(async () => {
       setupApplicationTarget(harness);
     });
 
     it('should generate a json summary report when specified', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: true,
-        codeCoverageReporters: ['json-summary'] as any,
+        coverage: true,
+        coverageReporters: ['json-summary'] as any,
       });
 
       const { result } = await harness.executeOnce();
@@ -35,8 +35,8 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
     it('should generate multiple reports when specified', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: true,
-        codeCoverageReporters: ['json-summary', 'lcov'] as any,
+        coverage: true,
+        coverageReporters: ['json-summary', 'lcov'] as any,
       });
 
       const { result } = await harness.executeOnce();

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

@@ -15,26 +15,26 @@ import {
 } from '../setup';
 
 describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
-  describe('Option: "codeCoverage"', () => {
+  describe('Option: "coverage"', () => {
     beforeEach(async () => {
       setupApplicationTarget(harness);
     });
 
-    it('should not generate a code coverage report when codeCoverage is false', async () => {
+    it('should not generate a code coverage report when coverage is false', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: false,
+        coverage: false,
       });
 
       const { result } = await harness.executeOnce();
       expect(result?.success).toBeTrue();
       expect(harness.hasFile('coverage/test/index.html')).toBeFalse();
     });
 
-    it('should generate a code coverage report when codeCoverage is true', async () => {
+    it('should generate a code coverage report when coverage is true', async () => {
       harness.useTarget('test', {
         ...BASE_OPTIONS,
-        codeCoverage: true,
+        coverage: true,
       });
 
       const { result } = await harness.executeOnce();