feat(plugin-eslint): provide Nx helper to combine eslint config from all projects

Author: matejchalk

packages/plugin-eslint/src/index.ts

@@ -3,3 +3,5 @@ import { eslintPlugin } from './lib/eslint-plugin';
 export default eslintPlugin;
 
 export type { ESLintPluginConfig } from './lib/config';
+
+export { eslintConfigFromNxProjects } from './lib/nx';

packages/plugin-eslint/src/lib/nx/find-all-projects.ts

@@ -0,0 +1,50 @@
+import {
+  createProjectGraphAsync,
+  readProjectsConfigurationFromProjectGraph,
+} from '@nx/devkit';
+import type { ESLint } from 'eslint';
+import type { ESLintPluginConfig } from '../config';
+import {
+  findCodePushupEslintrc,
+  getEslintConfig,
+  getLintFilePatterns,
+} from './utils';
+
+export async function eslintConfigFromNxProjects(): Promise<ESLintPluginConfig> {
+  // find Nx projects with lint target
+  const projectGraph = await createProjectGraphAsync({ exitOnError: false });
+  const projectsConfiguration =
+    readProjectsConfigurationFromProjectGraph(projectGraph);
+  const projects = Object.values(projectsConfiguration.projects).filter(
+    project => 'lint' in (project.targets ?? {}),
+  );
+
+  // create single ESLint config with project-specific overrides
+  const eslintConfig: ESLint.ConfigData = {
+    root: true,
+    overrides: await Promise.all(
+      projects.map(async project => ({
+        files: getLintFilePatterns(project),
+        extends:
+          (await findCodePushupEslintrc(project)) ?? getEslintConfig(project),
+      })),
+    ),
+  };
+
+  // include patterns from each project
+  const patterns = projects.flatMap(project => [
+    ...getLintFilePatterns(project),
+    // HACK: ESLint.calculateConfigForFile won't find rules included only for subsets of *.ts when globs used
+    // so we explicitly provide additional patterns used by @code-pushup/eslint-config to ensure those rules are included
+    // this workaround won't be necessary once flat configs are stable (much easier to find all rules)
+    `${project.sourceRoot}/*.test.ts`, // jest/* and vitest/* rules
+    `${project.sourceRoot}/*.cy.ts`, // cypress/* rules
+    `${project.sourceRoot}/*.stories.ts`, // storybook/* rules
+    `${project.sourceRoot}/.storybook/main.ts`, // storybook/no-uninstalled-addons rule
+  ]);
+
+  return {
+    eslintrc: eslintConfig,
+    patterns,
+  };
+}

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

@@ -0,0 +1 @@
+export { eslintConfigFromNxProjects } from './find-all-projects';

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

@@ -0,0 +1,36 @@
+import type { ProjectConfiguration } from '@nx/devkit';
+import { fileExists, toArray } from '@code-pushup/utils';
+
+export async function findCodePushupEslintrc(
+  project: ProjectConfiguration,
+): Promise<string | null> {
+  const name = 'code-pushup.eslintrc';
+  // https://eslint.org/docs/latest/use/configure/configuration-files#configuration-file-formats
+  const extensions = ['json', 'js', 'cjs', 'yml', 'yaml'];
+
+  // eslint-disable-next-line functional/no-loop-statements
+  for (const ext of extensions) {
+    const filename = `./${project.root}/${name}.${ext}`;
+    if (await fileExists(filename)) {
+      return filename;
+    }
+  }
+
+  return null;
+}
+
+export function getLintFilePatterns(project: ProjectConfiguration): string[] {
+  const options = project.targets?.['lint']?.options as
+    | { lintFilePatterns?: string | string[] }
+    | undefined;
+  return options?.lintFilePatterns == null
+    ? []
+    : toArray(options.lintFilePatterns);
+}
+
+export function getEslintConfig(project: ProjectConfiguration): string {
+  const options = project.targets?.['lint']?.options as
+    | { eslintConfig?: string }
+    | undefined;
+  return options?.eslintConfig ?? `${project.root}/.eslintrc.json`;
+}

packages/utils/src/index.ts

@@ -7,7 +7,34 @@ export {
   executeProcess,
   objectToCliArgs,
 } from './lib/execute-process';
+export {
+  FileResult,
+  MultipleFileResults,
+  crawlFileSystem,
+  ensureDirectoryExists,
+  fileExists,
+  findLineNumberInText,
+  importEsmModule,
+  logMultipleFileResults,
+  pluginWorkDir,
+  readJsonFile,
+  readTextFile,
+  toUnixPath,
+} from './lib/file-system';
+export {
+  formatBytes,
+  formatDuration,
+  pluralize,
+  pluralizeToken,
+  slugify,
+} from './lib/formatting';
 export { getLatestCommit, git } from './lib/git';
+export {
+  isPromiseFulfilledResult,
+  isPromiseRejectedResult,
+} from './lib/guards';
+export { logMultipleResults } from './lib/log-results';
+export { NEW_LINE } from './lib/md';
 export { ProgressBar, getProgressBar } from './lib/progress';
 export {
   CODE_PUSHUP_DOMAIN,
@@ -21,37 +48,11 @@ 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,
-  pluginWorkDir,
-  crawlFileSystem,
-  findLineNumberInText,
-} from './lib/file-system';
-export { verboseUtils } from './lib/verbose-utils';
-export {
-  toArray,
-  objectToKeys,
-  objectToEntries,
   countOccurrences,
   distinct,
   factorOf,
+  objectToEntries,
+  objectToKeys,
+  toArray,
 } from './lib/transformation';
-export {
-  slugify,
-  pluralize,
-  pluralizeToken,
-  formatBytes,
-  formatDuration,
-} from './lib/formatting';
-export { NEW_LINE } from './lib/md';
-export { logMultipleResults } from './lib/log-results';
-export {
-  isPromiseFulfilledResult,
-  isPromiseRejectedResult,
-} from './lib/guards';
+export { verboseUtils } from './lib/verbose-utils';

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

@@ -5,6 +5,25 @@ import { join } from 'path';
 import { formatBytes } from './formatting';
 import { logMultipleResults } from './log-results';
 
+export async function readTextFile(path: string): Promise<string> {
+  const buffer = await readFile(path);
+  return buffer.toString();
+}
+
+export async function readJsonFile<T = unknown>(path: string): Promise<T> {
+  const text = await readTextFile(path);
+  return JSON.parse(text);
+}
+
+export async function fileExists(path: string): Promise<boolean> {
+  try {
+    const stats = await stat(path);
+    return stats.isFile();
+  } catch {
+    return false;
+  }
+}
+
 export function toUnixPath(
   path: string,
   options?: { toRelative?: boolean },
@@ -30,16 +49,6 @@ export async function ensureDirectoryExists(baseDir: string) {
   }
 }
 
-export async function readTextFile(path: string): Promise<string> {
-  const buffer = await readFile(path);
-  return buffer.toString();
-}
-
-export async function readJsonFile<T = unknown>(path: string): Promise<T> {
-  const text = await readTextFile(path);
-  return JSON.parse(text);
-}
-
 export type FileResult = readonly [string] | readonly [string, number];
 export type MultipleFileResults = PromiseSettledResult<FileResult>[];