fix(linter): remove config builder option for @nrwl/linter:lint whe…

…n using eslint (#3093)

- eslint automatically detects .eslintrc files already
- removing the config option also enables nested configs
- provide a migration to remove config as long as users didn't customize it

packages/cypress/src/schematics/cypress-project/cypress-project.spec.ts

@@ -82,7 +82,6 @@ describe('schematic:cypress-project', () => {
         builder: '@nrwl/linter:lint',
         options: {
           linter: 'eslint',
-          config: 'apps/my-app-e2e/.eslintrc',
           tsConfig: ['apps/my-app-e2e/tsconfig.e2e.json'],
           exclude: ['**/node_modules/**', '!apps/my-app-e2e/**'],
         },

packages/linter/src/builders/lint/lint.impl.ts

@@ -1,12 +1,12 @@
-import { createBuilder } from '@angular-devkit/architect';
+import { BuilderContext, createBuilder } from '@angular-devkit/architect';
 import { CLIEngine } from 'eslint';
-import { writeFileSync, mkdirSync } from 'fs';
+import { writeFileSync } from 'fs';
 import * as path from 'path';
 import { Schema } from './schema';
-import { BuilderContext } from '@angular-devkit/architect';
 import { createProgram } from './utility/ts-utils';
 import { lint, loadESLint } from './utility/eslint-utils';
 import { createDirectory } from '@nrwl/workspace';
+
 /**
  * Adapted from @angular-eslint/builder source
  */
@@ -41,7 +41,11 @@ async function run(options: Schema, context: BuilderContext): Promise<any> {
     throw new Error('ESLint must be version 6.1 or higher.');
   }
 
-  const eslintConfigPath = path.resolve(systemRoot, options.config);
+  // We want users to have the option of not specifying the config path, and let
+  // eslint automatically resolve the `.eslintrc` files in each folder.
+  const eslintConfigPath = options.config
+    ? path.resolve(systemRoot, options.config)
+    : undefined;
 
   let lintReports: CLIEngine.LintReport[] = [];
   const lintedFiles = new Set<string>();

packages/linter/src/builders/lint/utility/eslint-utils.spec.ts

@@ -50,10 +50,10 @@ describe('eslint-util', () => {
     ).catch(() => {});
     expect(CLIEngine).toHaveBeenCalledWith({
       configFile: './.eslintrc',
-      useEslintrc: false,
       fix: true,
       cache: true,
       cacheLocation: '/root/cache',
+      useEslintrc: true,
     });
   });
   it('should not lint the same files twice', async () => {

packages/linter/src/builders/lint/utility/eslint-utils.ts

@@ -33,7 +33,7 @@ export async function lint(
   const projectESLint = await loadESLint();
   const cli: CLIEngine = new projectESLint.CLIEngine({
     configFile: eslintConfigPath,
-    useEslintrc: false,
+    useEslintrc: true,
     fix: !!options.fix,
     cache: !!options.cache,
     cacheLocation: options.cacheLocation,

packages/next/src/schematics/application/files/index.d.ts__tmpl__

@@ -1,3 +1,4 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
 declare module '*.svg' {
   const content: any;
   export const ReactComponent: any;

packages/workspace/migrations.json

@@ -74,6 +74,11 @@
       "version": "9.3.0-beta.1",
       "description": "Update prettier to v2",
       "factory": "./src/migrations/update-9-3-0/update-9-3-0"
+    },
+    "update-eslint-config": {
+      "version": "9.4.0-beta.1",
+      "description": "Remove config builder option when using eslint to enable automatic detection",
+      "factory": "./src/migrations/update-9-4-0/update-eslint-config"
     }
   },
   "packageJsonUpdates": {

packages/workspace/src/migrations/update-9-4-0/update-eslint-config.spec.ts

@@ -0,0 +1,87 @@
+import { Tree } from '@angular-devkit/schematics';
+import { readWorkspace } from '@nrwl/workspace';
+import { createEmptyWorkspace } from '@nrwl/workspace/testing';
+import { callRule, runMigration } from '../../utils/testing';
+import { updateWorkspace } from '@nrwl/workspace/src/utils/workspace';
+
+describe('Update eslint config for 9.4.0', () => {
+  let tree: Tree;
+
+  beforeEach(async () => {
+    tree = Tree.empty();
+    tree = createEmptyWorkspace(tree);
+    tree = await callRule(
+      updateWorkspace((workspace) => {
+        workspace.projects.add({
+          name: 'proj1',
+          root: 'proj1',
+          architect: {
+            lint: {
+              builder: '@angular-devkit/build-angular:tslint',
+              options: {
+                config: 'proj1/tslint.json',
+              },
+            },
+          },
+        });
+        workspace.projects.add({
+          name: 'proj2',
+          root: 'proj2',
+          architect: {
+            lint: {
+              builder: '@nrwl/linter:lint',
+              options: {
+                linter: 'eslint',
+                config: 'proj2/.eslintrc',
+              },
+            },
+          },
+        });
+        workspace.projects.add({
+          name: 'proj3',
+          root: 'proj3',
+          architect: {
+            lint: {
+              builder: '@nrwl/linter:lint',
+              options: {
+                linter: 'tslint',
+                config: 'proj3/tslint.json',
+              },
+            },
+          },
+        });
+        workspace.projects.add({
+          name: 'proj4',
+          root: 'proj4',
+          architect: {
+            lint: {
+              builder: '@nrwl/linter:lint',
+              options: {
+                linter: 'eslint',
+                config: 'proj4/.eslintrc.custom',
+              },
+            },
+          },
+        });
+      }),
+      tree
+    );
+  });
+
+  it('should remove config builder option when using eslint', async () => {
+    const result = await runMigration('update-eslint-config', {}, tree);
+
+    const json = readWorkspace(result);
+
+    expect(json.projects.proj1.architect.lint.options.config).toMatch(
+      'proj1/tslint.json'
+    );
+    expect(json.projects.proj2.architect.lint.options.config).toBeUndefined();
+    expect(json.projects.proj3.architect.lint.options.config).toMatch(
+      'proj3/tslint.json'
+    );
+    expect(json.projects.proj4.architect.lint.options.config).toMatch(
+      'proj4/.eslintrc.custom'
+    );
+  });
+});

packages/workspace/src/migrations/update-9-4-0/update-eslint-config.ts

@@ -0,0 +1,21 @@
+import { chain, SchematicContext, Tree } from '@angular-devkit/schematics';
+import { formatFiles, updateWorkspaceInTree } from '@nrwl/workspace';
+
+function removeEslintConfigOption(host: Tree, context: SchematicContext) {
+  return updateWorkspaceInTree((json) => {
+    Object.keys(json.projects).forEach((name) => {
+      const p = json.projects[name];
+      if (
+        p.architect?.lint.builder === '@nrwl/linter:lint' &&
+        p.architect?.lint.options?.config === `${p.root}/.eslintrc`
+      ) {
+        delete p.architect.lint.options.config;
+      }
+    });
+    return json;
+  });
+}
+
+export default function () {
+  return chain([removeEslintConfigOption, formatFiles()]);
+}

packages/workspace/src/utils/lint.ts

@@ -37,8 +37,10 @@ export function generateProjectLint(
     return {
       builder: '@nrwl/linter:lint',
       options: {
+        // No config option here because eslint resolve them automatically.
+        // By not specifying a config option we allow eslint to support
+        // nested configurations.
         linter: 'eslint',
-        config: projectRoot + '/.eslintrc',
         tsConfig: [tsConfigPath],
         exclude: ['**/node_modules/**', '!' + projectRoot + '/**'],
       },