fix(plugin-coverage): support non-cjs jest configs

refactored importEsmModule->importModule to be format-agnostic by default

fix #726

Author: matejchalk

packages/core/src/lib/implementation/read-rc-file.ts

@@ -5,7 +5,7 @@ import {
   SUPPORTED_CONFIG_FILE_FORMATS,
   coreConfigSchema,
 } from '@code-pushup/models';
-import { fileExists, importEsmModule } from '@code-pushup/utils';
+import { fileExists, importModule } from '@code-pushup/utils';
 
 export class ConfigPathError extends Error {
   constructor(configPath: string) {
@@ -25,7 +25,7 @@ export async function readRcByPath(
     throw new ConfigPathError(filepath);
   }
 
-  const cfg = await importEsmModule({ filepath, tsconfig });
+  const cfg = await importModule({ filepath, tsconfig, format: 'esm' });
 
   return coreConfigSchema.parse(cfg);
 }

packages/plugin-coverage/src/lib/nx/coverage-paths.ts

@@ -8,7 +8,7 @@ import type { JestExecutorOptions } from '@nx/jest/src/executors/jest/schema';
 import type { VitestExecutorOptions } from '@nx/vite/executors';
 import chalk from 'chalk';
 import { isAbsolute, join } from 'node:path';
-import { importEsmModule, ui } from '@code-pushup/utils';
+import { importModule, ui } from '@code-pushup/utils';
 import { CoverageResult } from '../config';
 
 /**
@@ -128,7 +128,7 @@ export async function getCoveragePathForVitest(
     );
   }
 
-  const vitestConfig = await importEsmModule<VitestCoverageConfig>({
+  const vitestConfig = await importModule<VitestCoverageConfig>({
     filepath: config,
     format: 'esm',
   });
@@ -165,9 +165,8 @@ export async function getCoveragePathForJest(
 ) {
   const { jestConfig } = options;
 
-  const testConfig = await importEsmModule<JestCoverageConfig>({
+  const testConfig = await importModule<JestCoverageConfig>({
     filepath: jestConfig,
-    format: 'cjs',
   });
   const { coverageDirectory, coverageReporters } = {
     ...testConfig,

packages/plugin-lighthouse/src/lib/runner/utils.ts

@@ -6,7 +6,7 @@ import experimentalConfig from 'lighthouse/core/config/experimental-config.js';
 import perfConfig from 'lighthouse/core/config/perf-config.js';
 import { Result } from 'lighthouse/types/lhr/audit-result';
 import { AuditOutput, AuditOutputs } from '@code-pushup/models';
-import { importEsmModule, readJsonFile, ui } from '@code-pushup/utils';
+import { importModule, readJsonFile, ui } from '@code-pushup/utils';
 import type { LighthouseOptions } from '../types';
 import { logUnsupportedDetails, toAuditDetails } from './details/details';
 import { LighthouseCliFlags } from './types';
@@ -126,7 +126,7 @@ export async function getConfig(
       // Resolve the config file path relative to where cli was called.
       return readJsonFile<Config>(filepath);
     } else if (/\.(ts|js|mjs)$/.test(filepath)) {
-      return importEsmModule<Config>({ filepath });
+      return importModule<Config>({ filepath, format: 'esm' });
     } else {
       ui().logger.info(`Format of file ${filepath} not supported`);
     }

packages/utils/mocks/fixtures/valid-cjs-module-export.cjs

@@ -0,0 +1 @@
+module.exports = 'valid-cjs-module-export';

packages/utils/src/index.ts

@@ -17,7 +17,7 @@ export {
   fileExists,
   filePathToCliArg,
   findLineNumberInText,
-  importEsmModule,
+  importModule,
   logMultipleFileResults,
   pluginWorkDir,
   readJsonFile,

packages/utils/src/lib/file-system.integration.test.ts

@@ -1,31 +1,41 @@
 import { join } from 'node:path';
 import { describe, expect, it } from 'vitest';
-import { importEsmModule } from './file-system';
+import { importModule } from './file-system';
 
-describe('importEsmModule', () => {
+describe('importModule', () => {
   const mockDir = join(process.cwd(), 'packages', 'utils', 'mocks', 'fixtures');
 
   it('should load a valid ES module', async () => {
     await expect(
-      importEsmModule({
+      importModule({
         filepath: join(mockDir, 'valid-es-module-export.mjs'),
       }),
     ).resolves.toBe('valid-es-module-export');
   });
 
-  it('should throw if the file does not exist', async () => {
+  it('should load a valid CommonJS module', async () => {
     await expect(
-      importEsmModule({
-        filepath: 'path/to/non-existent-export.mjs',
+      importModule({
+        filepath: join(mockDir, 'valid-cjs-module-export.cjs'),
       }),
-    ).rejects.toThrow('non-existent-export.mjs');
+    ).resolves.toBe('valid-cjs-module-export');
   });
 
-  it('should throw if the file does not have any default export', async () => {
+  it('should load an ES module without default export', async () => {
     await expect(
-      importEsmModule({
+      importModule({
         filepath: join(mockDir, 'no-default-export.mjs'),
       }),
-    ).rejects.toThrow('No default export found');
+    ).resolves.toEqual(
+      expect.objectContaining({ exportedVar: 'exported-variable' }),
+    );
+  });
+
+  it('should throw if the file does not exist', async () => {
+    await expect(
+      importModule({
+        filepath: 'path/to/non-existent-export.mjs',
+      }),
+    ).rejects.toThrow('non-existent-export.mjs');
   });
 });

packages/utils/src/lib/file-system.ts

@@ -75,24 +75,13 @@ export function logMultipleFileResults(
   );
 }
 
-export class NoExportError extends Error {
-  constructor(filepath: string) {
-    super(`No default export found in ${filepath}`);
-  }
-}
-
-export async function importEsmModule<T = unknown>(
-  options: Options,
-): Promise<T> {
-  const { mod } = await bundleRequire<object>({
-    format: 'esm',
-    ...options,
-  });
+export async function importModule<T = unknown>(options: Options): Promise<T> {
+  const { mod } = await bundleRequire<object>(options);
 
-  if (!('default' in mod)) {
-    throw new NoExportError(options.filepath);
+  if (typeof mod === 'object' && 'default' in mod) {
+    return mod.default as T;
   }
-  return mod.default as T;
+  return mod as T;
 }
 
 export function pluginWorkDir(slug: string): string {