refactor: log warnings for unsupported options in Web Test Runner

This helps notify users when they are attempting to use an option from Karma which hasn't been implemented yet.

Author: dgp1130

packages/angular_devkit/build_angular/src/builders/web-test-runner/builder-status-warnings.ts

@@ -0,0 +1,48 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import { BuilderContext } from '@angular-devkit/architect';
+import { Schema as WtrBuilderOptions } from './schema';
+
+const UNSUPPORTED_OPTIONS: Array<keyof WtrBuilderOptions> = [
+  'main',
+  'assets',
+  'scripts',
+  'styles',
+  'inlineStyleLanguage',
+  'stylePreprocessorOptions',
+  'sourceMap',
+  'progress',
+  'poll',
+  'preserveSymlinks',
+  'browsers',
+  'codeCoverage',
+  'codeCoverageExclude',
+  'fileReplacements',
+  'webWorkerTsConfig',
+];
+
+/** Logs a warning for any unsupported options specified. */
+export function logBuilderStatusWarnings(options: WtrBuilderOptions, ctx: BuilderContext) {
+  // Validate supported options
+  for (const unsupportedOption of UNSUPPORTED_OPTIONS) {
+    const value = (options as unknown as WtrBuilderOptions)[unsupportedOption];
+
+    if (value === undefined || value === false) {
+      continue;
+    }
+    if (Array.isArray(value) && value.length === 0) {
+      continue;
+    }
+    if (typeof value === 'object' && Object.keys(value).length === 0) {
+      continue;
+    }
+
+    ctx.logger.warn(`The '${unsupportedOption}' option is not yet supported by this builder.`);
+  }
+}

packages/angular_devkit/build_angular/src/builders/web-test-runner/index.ts

@@ -16,6 +16,7 @@ import path from 'path';
 import { findTestFiles } from '../../utils/test-files';
 import { buildApplicationInternal } from '../application';
 import { OutputHashing } from '../browser-esbuild/schema';
+import { logBuilderStatusWarnings } from './builder-status-warnings';
 import { WtrBuilderOptions, normalizeOptions } from './options';
 import { Schema } from './schema';
 
@@ -24,6 +25,7 @@ export default createBuilder(
     ctx.logger.warn(
       'NOTE: The Web Test Runner builder is currently EXPERIMENTAL and not ready for production use.',
     );
+    logBuilderStatusWarnings(schema, ctx);
 
     const options = normalizeOptions(schema);
     const testDir = 'dist/test-out';