Add Karma configuration from Angular plugin configuration

packages/knip/fixtures/plugins/angular/package.json

@@ -10,6 +10,12 @@
   },
   "devDependencies": {
     "@angular/cli": "*",
+    "karma": "*",
+    "karma-chrome-launcher": "*",
+    "karma-coverage": "*",
+    "karma-jasmine": "*",
+    "karma-jasmine-html-reporter": "*",
+    "jasmine-core": "*",
     "typescript": "*"
   }
 }

packages/knip/fixtures/plugins/angular2/angular.json

@@ -98,7 +98,8 @@
               }
             ],
             "styles": ["src/styles.css"],
-            "scripts": []
+            "scripts": [],
+            "karmaConfig": "another-karma.conf.js"
           }
         }
       }

packages/knip/fixtures/plugins/angular2/package.json

@@ -7,6 +7,7 @@
     "@angular/cli": "*",
     "@angular/ssr": "*",
     "@angular-builders/custom-esbuild": "*",
-    "@angular-devkit/build-angular": "*"
+    "@angular-devkit/build-angular": "*",
+    "karma": "*"
   }
 }

packages/knip/src/plugins/angular/index.ts

@@ -2,7 +2,8 @@ import type { IsPluginEnabled, Plugin, ResolveConfig } from '../../types/config.
 import { type Input, toConfig, toDependency, toEntry, toProductionEntry } from '../../util/input.js';
 import { join } from '../../util/path.js';
 import { hasDependency } from '../../util/plugin.js';
-import type { AngularCLIWorkspaceConfiguration, WebpackBrowserSchemaForBuildFacade } from './types.js';
+import * as karma from '../karma/helpers.js';
+import type { AngularCLIWorkspaceConfiguration, KarmaTarget, WebpackBrowserSchemaForBuildFacade } from './types.js';
 
 // https://angular.io/guide/workspace-config
 
@@ -61,6 +62,34 @@ const resolveConfig: ResolveConfig<AngularCLIWorkspaceConfiguration> = async (co
           }
         }
       }
+      if (target.builder === '@angular-devkit/build-angular:karma' && opts) {
+        const karmaBuilderOptions = opts as KarmaTarget;
+        // https://github.com/angular/angular-cli/blob/19.0.6/packages/angular_devkit/build_angular/src/builders/karma/schema.json#L143
+        const testFilePatterns = karmaBuilderOptions.include ?? ['**/*.spec.ts'];
+        for (const testFilePattern of testFilePatterns) {
+          inputs.add(toEntry(testFilePattern));
+        }
+        // https://github.com/angular/angular-cli/blob/19.0.6/packages/angular_devkit/build_angular/src/builders/karma/schema.json#L146
+        const excludedTestFilePatterns = karmaBuilderOptions.exclude ?? [];
+        for (const excludedTestFilePattern of excludedTestFilePatterns) {
+          inputs.add(toEntry(`!${excludedTestFilePattern}`));
+        }
+        const karmaConfig = karmaBuilderOptions.karmaConfig;
+        if (!karmaConfig) {
+          // Hardcoded default Karma config from Angular builder
+          // https://github.com/angular/angular-cli/blob/19.0.6/packages/angular_devkit/build_angular/src/builders/karma/index.ts#L115
+          karma
+            .inputsFromPlugins(
+              ['karma-jasmine', 'karma-chrome-launcher', 'karma-jasmine-html-reporter', 'karma-coverage'],
+              options.manifest.devDependencies
+            )
+            .forEach(inputs.add, inputs);
+          karma.inputsFromFrameworks(['jasmine']).forEach(inputs.add, inputs);
+        }
+        if (karmaConfig && !karma.configFiles.includes(karmaConfig)) {
+          inputs.add(toConfig('karma', karmaConfig, options.configFilePath));
+        }
+      }
     }
   }
 

packages/knip/src/plugins/angular/types.ts

@@ -2533,7 +2533,7 @@ interface ExtractI18NTarget1 {
 /**
  * Karma target options for Build Facade.
  */
-interface KarmaTarget {
+export interface KarmaTarget {
   /**
    * The name of the main entry-point file.
    */

packages/knip/src/plugins/karma/helpers.ts

@@ -0,0 +1,51 @@
+import { type Input, toDeferResolveEntry, toDevDependency } from '../../util/input.js';
+import { isInternal } from '../../util/path.js';
+import type { Config, ConfigOptions } from './types.js';
+
+//👇 All but CoffeeScript ones. Low usage nowadays compared to the effort to implement support for those files
+export const configFiles = ['karma.conf.js', 'karma.conf.ts', '.config/karma.conf.js', '.config/karma.conf.ts'];
+
+export const inputsFromFrameworks = (frameworks: readonly string[]): readonly Input[] =>
+  frameworks.map(framework => {
+    return toDevDependency(framework === 'jasmine' ? 'jasmine-core' : framework);
+  });
+
+export const inputsFromPlugins = (
+  plugins: ConfigOptions['plugins'],
+  devDependencies: Record<string, string> | undefined
+): readonly Input[] => {
+  if (!plugins) {
+    const karmaPluginDevDeps = Object.keys(devDependencies ?? {}).filter(name => name.startsWith('karma-'));
+    return karmaPluginDevDeps.map(karmaPluginDevDep => toDevDependency(karmaPluginDevDep));
+  }
+  return plugins
+    .map(plugin => {
+      if (typeof plugin !== 'string') return;
+      return isInternal(plugin) ? toDeferResolveEntry(plugin) : toDevDependency(plugin);
+    })
+    .filter(input => !!input);
+};
+
+export type ConfigFile = (config: Config) => void;
+export const loadConfig = (configFile: ConfigFile): ConfigOptions | undefined => {
+  if (typeof configFile !== 'function') return;
+  const inMemoryConfig = new InMemoryConfig();
+  configFile(inMemoryConfig);
+  return inMemoryConfig.config ?? {};
+};
+
+/**
+ * Dummy configuration class with no default config options
+ * Relevant config options' defaults are empty, so that's good enough
+ * Real class: https://github.com/karma-runner/karma/blob/v6.4.4/lib/config.js#L275
+ */
+class InMemoryConfig implements Config {
+  config?: ConfigOptions;
+  /**
+   * Real method merges configurations with Lodash's `mergeWith`
+   * https://github.com/karma-runner/karma/blob/v6.4.4/lib/config.js#L343
+   */
+  set(config: ConfigOptions) {
+    this.config = config;
+  }
+}

packages/knip/src/plugins/karma/index.ts

@@ -1,8 +1,8 @@
 import type { IsPluginEnabled, Plugin, ResolveConfig, ResolveEntryPaths } from '../../types/config.js';
-import { type Input, toDeferResolveEntry, toDevDependency, toEntry } from '../../util/input.js';
-import { isInternal, join } from '../../util/path.js';
+import { type Input, toEntry } from '../../util/input.js';
+import { join } from '../../util/path.js';
 import { hasDependency } from '../../util/plugin.js';
-import type { Config, ConfigOptions } from './types.js';
+import { type ConfigFile, configFiles, inputsFromFrameworks, inputsFromPlugins, loadConfig } from './helpers.js';
 
 // https://karma-runner.github.io/latest/config/configuration-file.html
 
@@ -12,50 +12,29 @@ const enablers = ['karma'];
 
 const isEnabled: IsPluginEnabled = ({ dependencies }) => hasDependency(dependencies, enablers);
 
-//👇 All but CoffeeScript ones. Low usage nowadays compared to the effort to implement support for those files
-const config = ['karma.conf.js', 'karma.conf.ts', '.config/karma.conf.js', '.config/karma.conf.ts'];
+const config = configFiles;
 
 const entry: string[] = [];
 
-type ConfigFile = (config: Config) => void;
-
 const resolveConfig: ResolveConfig<ConfigFile> = async (localConfig, options) => {
   const inputs = new Set<Input>();
 
   const config = loadConfig(localConfig);
+  if (!config) return [];
 
   if (config.frameworks) {
-    for (const framework of config.frameworks) {
-      inputs.add(toDevDependency(devDepForFramework(framework)));
-    }
-  }
-  if (config.plugins) {
-    for (const plugin of config.plugins) {
-      if (typeof plugin !== 'string') continue;
-      if (isInternal(plugin)) {
-        inputs.add(toDeferResolveEntry(plugin));
-      } else {
-        inputs.add(toDevDependency(plugin));
-      }
-    }
-  } else {
-    const karmaPluginDevDeps = Object.keys(options.manifest.devDependencies ?? {}).filter(name =>
-      name.startsWith('karma-')
-    );
-    for (const karmaPluginDevDep of karmaPluginDevDeps) {
-      inputs.add(toDevDependency(karmaPluginDevDep));
-    }
+    inputsFromFrameworks(config.frameworks).forEach(inputs.add, inputs);
   }
+  inputsFromPlugins(config.plugins, options.manifest.devDependencies).forEach(inputs.add, inputs);
 
   return Array.from(inputs);
 };
 
-const devDepForFramework = (framework: string): string => (framework === 'jasmine' ? 'jasmine-core' : framework);
-
 const resolveEntryPaths: ResolveEntryPaths<ConfigFile> = (localConfig, options) => {
   const inputs = new Set<Input>();
 
   const config = loadConfig(localConfig);
+  if (!config) return [];
 
   const basePath = config.basePath ?? '';
   if (config.files) {
@@ -73,28 +52,6 @@ const resolveEntryPaths: ResolveEntryPaths<ConfigFile> = (localConfig, options)
   return Array.from(inputs);
 };
 
-const loadConfig = (configFile: ConfigFile): ConfigOptions => {
-  const inMemoryConfig = new InMemoryConfig();
-  configFile(inMemoryConfig);
-  return inMemoryConfig.config ?? {};
-};
-
-/**
- * Dummy configuration class with no default config options
- * Relevant config options' defaults are empty, so that's good enough
- * Real class: https://github.com/karma-runner/karma/blob/v6.4.4/lib/config.js#L275
- */
-class InMemoryConfig implements Config {
-  config?: ConfigOptions;
-  /**
-   * Real method merges configurations with Lodash's `mergeWith`
-   * https://github.com/karma-runner/karma/blob/v6.4.4/lib/config.js#L343
-   */
-  set(config: ConfigOptions) {
-    this.config = config;
-  }
-}
-
 export default {
   title,
   enablers,

packages/knip/test/plugins/angular.test.ts

@@ -15,12 +15,14 @@ test('Find dependencies with the Angular plugin', async () => {
 
   assert(issues.unlisted['angular.json']['@angular-devkit/build-angular']);
   assert(issues.unresolved['tsconfig.spec.json']['jasmine']);
+  assert(issues.devDependencies['package.json']['karma']);
 
   assert.deepEqual(counters, {
     ...baseCounters,
+    devDependencies: 1,
     unlisted: 1,
     unresolved: 1,
-    processed: 1,
-    total: 1,
+    processed: 2,
+    total: 2,
   });
 });

packages/knip/test/plugins/angular2.test.ts

@@ -8,14 +8,17 @@ import baseCounters from '../helpers/baseCounters.js';
 const cwd = resolve('fixtures/plugins/angular2');
 
 test('Find dependencies with the Angular plugin (2)', async () => {
-  const { counters } = await main({
+  const { issues, counters } = await main({
     ...baseArguments,
     cwd,
   });
 
+  assert(issues.devDependencies['package.json']['karma']);
+
   assert.deepEqual(counters, {
     ...baseCounters,
-    processed: 5,
-    total: 5,
+    devDependencies: 1,
+    processed: 7,
+    total: 7,
   });
 });