feat(plugin-eslint): add support for inline eslint config

Author: matejchalk

packages/plugin-eslint/src/lib/config.ts

@@ -1,12 +1,19 @@
-import { z } from 'zod';
+import type { ESLint } from 'eslint';
+import { type ZodType, z } from 'zod';
 
 export const eslintPluginConfigSchema = z.object({
-  eslintrc: z.string({
-    description: 'Path to .eslintrc.* config file',
-  }),
+  eslintrc: z.union(
+    [
+      z.string({ description: 'Path to ESLint config file' }),
+      z.record(z.string(), z.unknown(), {
+        description: 'ESLint config object',
+      }) as ZodType<ESLint.ConfigData>,
+    ],
+    { description: 'ESLint config as file path or inline object' },
+  ),
   patterns: z.union([z.string(), z.array(z.string()).min(1)], {
     description:
-      'Lint target files. May contain file paths, directory paths, or glob patterns',
+      'Lint target files. May contain file paths, directory paths or glob patterns',
   }),
 });
 

packages/plugin-eslint/src/lib/eslint-plugin.ts

@@ -1,11 +1,12 @@
-import { ESLint } from 'eslint';
+import { writeFile } from 'fs/promises';
 import { dirname, join } from 'path';
 import { fileURLToPath } from 'url';
 import { PluginConfig } from '@code-pushup/models';
 import { name, version } from '../../package.json';
 import { ESLintPluginConfig, eslintPluginConfigSchema } from './config';
 import { listAuditsAndGroups } from './meta';
-import { createRunnerConfig } from './runner';
+import { ESLINTRC_PATH, createRunnerConfig } from './runner';
+import { setupESLint } from './setup';
 
 /**
  * Instantiates Code PushUp ESLint plugin for use in core config.
@@ -32,13 +33,16 @@ export async function eslintPlugin(
 ): Promise<PluginConfig> {
   const { eslintrc, patterns } = eslintPluginConfigSchema.parse(config);
 
-  const eslint = new ESLint({
-    overrideConfigFile: eslintrc,
-    useEslintrc: false,
-  });
+  const eslint = setupESLint(eslintrc);
 
   const { audits, groups } = await listAuditsAndGroups(eslint, patterns);
 
+  // save inline config to file so runner can access it later
+  if (typeof eslintrc !== 'string') {
+    await writeFile(ESLINTRC_PATH, JSON.stringify(eslintrc));
+  }
+  const eslintrcPath = typeof eslintrc === 'string' ? eslintrc : ESLINTRC_PATH;
+
   const runnerScriptPath = join(
     fileURLToPath(dirname(import.meta.url)),
     'bin.js',
@@ -56,6 +60,11 @@ export async function eslintPlugin(
     audits,
     groups,
 
-    runner: createRunnerConfig(runnerScriptPath, audits, eslintrc, patterns),
+    runner: createRunnerConfig(
+      runnerScriptPath,
+      audits,
+      eslintrcPath,
+      patterns,
+    ),
   };
 }

packages/plugin-eslint/src/lib/runner/index.ts

@@ -1,13 +1,14 @@
 import { mkdir, writeFile } from 'fs/promises';
 import { platform } from 'os';
-import { dirname } from 'path';
+import { dirname, join } from 'path';
 import type { Audit, AuditOutput, RunnerConfig } from '@code-pushup/models';
-import { toArray } from '@code-pushup/utils';
+import { pluginWorkDir, readJsonFile, toArray } from '@code-pushup/utils';
 import { lint } from './lint';
 import { lintResultsToAudits } from './transform';
 
-export const RUNNER_OUTPUT_PATH =
-  'node_modules/.code-pushup/eslint/runner-output.json';
+const WORKDIR = pluginWorkDir('eslint');
+export const RUNNER_OUTPUT_PATH = join(WORKDIR, 'runner-output.json');
+export const ESLINTRC_PATH = join(WORKDIR, '.eslintrc.json');
 
 const AUDIT_SLUGS_SEP = ',';
 
@@ -23,7 +24,12 @@ export async function executeRunner(argv = process.argv): Promise<void> {
     throw new Error('Invalid runner args - missing patterns argument');
   }
 
-  const lintResults = await lint(eslintrc, patterns);
+  const lintResults = await lint({
+    // if file created from inline object, provide inline to preserve relative links
+    eslintrc:
+      eslintrc === ESLINTRC_PATH ? await readJsonFile(eslintrc) : eslintrc,
+    patterns,
+  });
   const failedAudits = lintResultsToAudits(lintResults);
 
   const audits = slugs.split(AUDIT_SLUGS_SEP).map(

packages/plugin-eslint/src/lib/runner/lint.ts

@@ -1,16 +1,14 @@
-import { ESLint, type Linter } from 'eslint';
+import type { Linter } from 'eslint';
 import { distinct, toArray, toUnixPath } from '@code-pushup/utils';
+import { ESLintPluginConfig } from '../config';
+import { setupESLint } from '../setup';
 import type { LintResult, LinterOutput, RuleOptionsPerFile } from './types';
 
-export async function lint(
-  eslintrc: string,
-  patterns: string[],
-): Promise<LinterOutput> {
-  const eslint = new ESLint({
-    overrideConfigFile: eslintrc,
-    useEslintrc: false,
-    errorOnUnmatchedPattern: false,
-  });
+export async function lint({
+  eslintrc,
+  patterns,
+}: ESLintPluginConfig): Promise<LinterOutput> {
+  const eslint = setupESLint(eslintrc);
 
   const lintResults = await eslint.lintFiles(patterns);
   const results = lintResults.map(

packages/plugin-eslint/src/lib/runner/lint.unit.test.ts

@@ -1,4 +1,5 @@
 import { ESLint, Linter } from 'eslint';
+import { ESLintPluginConfig } from '../config';
 import { lint } from './lint';
 
 class MockESLint {
@@ -50,12 +51,17 @@ vi.mock('eslint', () => ({
 }));
 
 describe('lint', () => {
+  const config: ESLintPluginConfig = {
+    eslintrc: '.eslintrc.js',
+    patterns: ['**/*.js'],
+  };
+
   beforeEach(() => {
     vi.clearAllMocks();
   });
 
   it('should add relativeFilePath to each lint result', async () => {
-    const { results } = await lint('.eslintrc.js', ['**/*.js']);
+    const { results } = await lint(config);
     expect(results).toEqual([
       expect.objectContaining({ relativeFilePath: 'src/app/app.component.ts' }),
       expect.objectContaining({
@@ -68,7 +74,7 @@ describe('lint', () => {
   });
 
   it('should get rule options for each file', async () => {
-    const { ruleOptionsPerFile } = await lint('.eslintrc.js', ['**/*.js']);
+    const { ruleOptionsPerFile } = await lint(config);
     expect(ruleOptionsPerFile).toEqual({
       'src/app/app.component.ts': {
         'max-lines': [500],
@@ -85,7 +91,7 @@ describe('lint', () => {
   });
 
   it('should correctly use ESLint Node API', async () => {
-    await lint('.eslintrc.js', ['**/*.js']);
+    await lint(config);
     expect(ESLint).toHaveBeenCalledWith<ConstructorParameters<typeof ESLint>>({
       overrideConfigFile: '.eslintrc.js',
       useEslintrc: false,

packages/plugin-eslint/src/lib/setup.ts

@@ -0,0 +1,12 @@
+import { ESLint } from 'eslint';
+import { ESLintPluginConfig } from './config';
+
+export function setupESLint(eslintrc: ESLintPluginConfig['eslintrc']) {
+  return new ESLint({
+    ...(typeof eslintrc === 'string'
+      ? { overrideConfigFile: eslintrc }
+      : { baseConfig: eslintrc }),
+    useEslintrc: false,
+    errorOnUnmatchedPattern: false,
+  });
+}

packages/utils/src/index.ts

@@ -7,8 +7,25 @@ export {
   executeProcess,
   objectToCliArgs,
 } from './lib/execute-process';
-export { git, getLatestCommit } from './lib/git';
+export {
+  FileResult,
+  MultipleFileResults,
+  ensureDirectoryExists,
+  importEsmModule,
+  logMultipleFileResults,
+  pluginWorkDir,
+  readJsonFile,
+  readTextFile,
+  toUnixPath,
+} from './lib/file-system';
+export { getLatestCommit, git } from './lib/git';
+export { logMultipleResults } from './lib/log-results';
+export { NEW_LINE } from './lib/md';
 export { ProgressBar, getProgressBar } from './lib/progress';
+export {
+  isPromiseFulfilledResult,
+  isPromiseRejectedResult,
+} from './lib/promise-result';
 export {
   CODE_PUSHUP_DOMAIN,
   FOOTER_PREFIX,
@@ -23,28 +40,12 @@ export { reportToMd } from './lib/report-to-md';
 export { reportToStdout } from './lib/report-to-stdout';
 export { ScoredReport, scoreReport } from './lib/scoring';
 export {
-  readJsonFile,
-  readTextFile,
-  toUnixPath,
-  ensureDirectoryExists,
-  FileResult,
-  MultipleFileResults,
-  logMultipleFileResults,
-  importEsmModule,
-} from './lib/file-system';
-export { verboseUtils } from './lib/verbose-utils';
-export {
-  pluralize,
-  toArray,
-  objectToKeys,
-  objectToEntries,
   countOccurrences,
   distinct,
+  objectToEntries,
+  objectToKeys,
+  pluralize,
   slugify,
+  toArray,
 } from './lib/transformation';
-export { NEW_LINE } from './lib/md';
-export { logMultipleResults } from './lib/log-results';
-export {
-  isPromiseFulfilledResult,
-  isPromiseRejectedResult,
-} from './lib/promise-result';
+export { verboseUtils } from './lib/verbose-utils';

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

@@ -1,6 +1,7 @@
 import { type Options, bundleRequire } from 'bundle-require';
 import chalk from 'chalk';
 import { mkdir, readFile } from 'fs/promises';
+import { join } from 'path';
 import { logMultipleResults } from './log-results';
 import { formatBytes } from './report';
 
@@ -87,3 +88,7 @@ export async function importEsmModule<T = unknown>(
   }
   return parse(mod.default);
 }
+
+export function pluginWorkDir(slug: string): string {
+  return join('node_modules', '.code-pushup', slug);
+}