feat(linter): update-root-eslint-config-to-use-overrides migration

packages/linter/migrations.json

@@ -29,6 +29,11 @@
       "version": "10.4.0-beta.0",
       "description": "Update ESLint config files to use preset configs which eslint-plugin-nx exports",
       "factory": "./src/migrations/update-10-4-0/update-eslint-configs-to-use-nx-presets"
+    },
+    "update-root-eslint-config-to-use-overrides": {
+      "version": "10.4.0-beta.1",
+      "description": "Update root ESLint config to use overrides",
+      "factory": "./src/migrations/update-10-4-0/update-root-eslint-config-to-use-overrides"
     }
   },
   "packageJsonUpdates": {

packages/linter/src/migrations/update-10-4-0/update-root-eslint-config-to-use-overrides.spec.ts

@@ -0,0 +1,209 @@
+import { Tree } from '@angular-devkit/schematics';
+import { readJsonInTree } from '@nrwl/workspace';
+import { createEmptyWorkspace } from '@nrwl/workspace/testing';
+import { runMigration } from '../../utils/testing';
+
+describe('Update root ESLint config to use overrides', () => {
+  let tree: Tree;
+  beforeEach(async () => {
+    tree = Tree.empty();
+    tree = createEmptyWorkspace(tree);
+  });
+
+  const testCases = [
+    {
+      // Most recent root ESLint config (before this change) with no modifications
+      input: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        extends: ['plugin:@nrwl/nx/typescript'],
+        rules: {
+          '@nrwl/nx/enforce-module-boundaries': [
+            'error',
+            {
+              enforceBuildableLibDependency: true,
+              allow: [],
+              depConstraints: [
+                { sourceTag: '*', onlyDependOnLibsWithTags: ['*'] },
+              ],
+            },
+          ],
+        },
+      },
+      expected: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        overrides: [
+          {
+            files: ['*.ts', '*.tsx', '*.js', '*.jsx'],
+            rules: {
+              '@nrwl/nx/enforce-module-boundaries': [
+                'error',
+                {
+                  enforceBuildableLibDependency: true,
+                  allow: [],
+                  depConstraints: [
+                    { sourceTag: '*', onlyDependOnLibsWithTags: ['*'] },
+                  ],
+                },
+              ],
+            },
+          },
+          {
+            files: ['*.ts', '*.tsx'],
+            extends: ['plugin:@nrwl/nx/typescript'],
+            parserOptions: { project: './tsconfig.*?.json' },
+            rules: {},
+          },
+          {
+            files: ['*.js', '*.jsx'],
+            extends: ['plugin:@nrwl/nx/javascript'],
+            rules: {},
+          },
+        ],
+      },
+    },
+
+    {
+      // Example using custom overrides already (should be a noop)
+      input: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        extends: ['plugin:@nrwl/nx/typescript'],
+        overrides: [
+          {
+            files: ['*.ts'],
+            rules: {
+              foo: 'error',
+            },
+          },
+        ],
+      },
+      expected: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        extends: ['plugin:@nrwl/nx/typescript'],
+        overrides: [
+          {
+            files: ['*.ts'],
+            rules: {
+              foo: 'error',
+            },
+          },
+        ],
+      },
+    },
+
+    {
+      // Example using custom rules and plugins at the top-level
+      input: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx', 'plugin-a', 'plugin-b'],
+        extends: ['plugin:@nrwl/nx/typescript'],
+        rules: {
+          bar: 'warn',
+          'plugin-a/qux': ['error', { someConfig: true }],
+          'plugin-b/baz': 'off',
+        },
+      },
+      expected: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        overrides: [
+          {
+            files: ['*.ts', '*.tsx', '*.js', '*.jsx'],
+            plugins: ['plugin-a', 'plugin-b'],
+            rules: {
+              bar: 'warn',
+              'plugin-a/qux': ['error', { someConfig: true }],
+              'plugin-b/baz': 'off',
+            },
+          },
+          {
+            files: ['*.ts', '*.tsx'],
+            extends: ['plugin:@nrwl/nx/typescript'],
+            parserOptions: { project: './tsconfig.*?.json' },
+            rules: {},
+          },
+          {
+            files: ['*.js', '*.jsx'],
+            extends: ['plugin:@nrwl/nx/javascript'],
+            rules: {},
+          },
+        ],
+      },
+    },
+
+    {
+      // Example using other custom config at the top-level
+      input: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        settings: {
+          foo: 'bar',
+        },
+        env: {
+          browser: true,
+        },
+        parser: 'some-custom-parser-value',
+        parserOptions: {
+          custom: 'option',
+        },
+        extends: ['plugin:@nrwl/nx/typescript', 'custom-extends-config'],
+      },
+      expected: {
+        root: true,
+        ignorePatterns: ['**/*'],
+        plugins: ['@nrwl/nx'],
+        overrides: [
+          {
+            files: ['*.ts', '*.tsx', '*.js', '*.jsx'],
+            extends: ['custom-extends-config'],
+            env: {
+              browser: true,
+            },
+            settings: {
+              foo: 'bar',
+            },
+            parser: 'some-custom-parser-value',
+            parserOptions: {
+              custom: 'option',
+            },
+            rules: {},
+          },
+          {
+            files: ['*.ts', '*.tsx'],
+            extends: ['plugin:@nrwl/nx/typescript'],
+            parserOptions: { project: './tsconfig.*?.json' },
+            rules: {},
+          },
+          {
+            files: ['*.js', '*.jsx'],
+            extends: ['plugin:@nrwl/nx/javascript'],
+            rules: {},
+          },
+        ],
+      },
+    },
+  ];
+
+  testCases.forEach((tc, i) => {
+    it(`should update the existing root .eslintrc.json file to use overrides, CASE ${i}`, async () => {
+      tree.create('.eslintrc.json', JSON.stringify(tc.input));
+
+      const result = await runMigration(
+        'update-root-eslint-config-to-use-overrides',
+        {},
+        tree
+      );
+      expect(readJsonInTree(result, '.eslintrc.json')).toEqual(tc.expected);
+    });
+  });
+});

packages/linter/src/migrations/update-10-4-0/update-root-eslint-config-to-use-overrides.ts

@@ -0,0 +1,117 @@
+import { chain, noop, Tree } from '@angular-devkit/schematics';
+import { formatFiles, updateJsonInTree } from '@nrwl/workspace';
+import type { Linter } from 'eslint';
+
+/**
+ * We want to update the JSON in such a way that we:
+ * - translate the config to use overrides
+ * - don't break existing setups
+ *
+ * In order to achieve the second point we need to assume
+ * that any existing top level rules/plugins etc are intended
+ * to be run on all source files.
+ */
+function updateRootESLintConfig(host: Tree) {
+  return host.exists('.eslintrc.json')
+    ? updateJsonInTree('.eslintrc.json', (json: Linter.Config) => {
+        /**
+         * If the user already has overrides specified it is likely they have "forged their own path"
+         * when it comes to their ESLint setup, so we do nothing.
+         */
+        if (Array.isArray(json.overrides)) {
+          return json;
+        }
+
+        let normalizedExtends: string[] | undefined = undefined;
+        if (json.extends) {
+          if (typeof json.extends === 'string') {
+            normalizedExtends = [json.extends];
+          } else if (Array.isArray(json.extends)) {
+            normalizedExtends = json.extends;
+          }
+        }
+
+        json.overrides = [
+          /**
+           * This configuration is intended to apply to all "source code" (but not
+           * markup like HTML, or other custom file types like GraphQL).
+           *
+           * This is where we will apply any top-level config that the user currently
+           * has to ensure that it behaves the same before and after the migration.
+           */
+          {
+            files: ['*.ts', '*.tsx', '*.js', '*.jsx'],
+            extends: undefinedIfEmptyArr(
+              normalizedExtends
+                ? normalizedExtends.filter(
+                    (e) => e !== 'plugin:@nrwl/nx/typescript'
+                  )
+                : normalizedExtends
+            ),
+            env: json.env,
+            settings: json.settings,
+            parser: json.parser,
+            parserOptions: json.parserOptions,
+            plugins: undefinedIfEmptyArr(
+              json.plugins.filter((p) => p !== '@nrwl/nx') // remains at top-level, used everywhere
+            ),
+            rules: json.rules || {},
+          },
+
+          /**
+           * This configuration is intended to apply to all TypeScript source files.
+           * See the eslint-plugin-nx package for what is in the referenced shareable config.
+           */
+          {
+            files: ['*.ts', '*.tsx'],
+            extends: ['plugin:@nrwl/nx/typescript'],
+            parserOptions: { project: './tsconfig.*?.json' },
+            /**
+             * Having an empty rules object present makes it more obvious to the user where they would
+             * extend things from if they needed to
+             */
+            rules: {},
+          },
+
+          /**
+           * This configuration is intended to apply to all JavaScript source files.
+           * See the eslint-plugin-nx package for what is in the referenced shareable config.
+           */
+          {
+            files: ['*.js', '*.jsx'],
+            extends: ['plugin:@nrwl/nx/javascript'],
+            /**
+             * Having an empty rules object present makes it more obvious to the user where they would
+             * extend things from if they needed to
+             */
+            rules: {},
+          },
+        ];
+
+        /**
+         * Clean up after copying config to main override
+         */
+        json.plugins = ['@nrwl/nx'];
+        delete json.rules;
+        delete json.extends;
+        delete json.env;
+        delete json.settings;
+        delete json.globals;
+        delete json.parser;
+        delete json.parserOptions;
+
+        return json;
+      })
+    : noop();
+}
+
+function undefinedIfEmptyArr<T>(possibleArr: T): T | undefined {
+  if (Array.isArray(possibleArr) && possibleArr.length === 0) {
+    return undefined;
+  }
+  return possibleArr;
+}
+
+export default function () {
+  return chain([updateRootESLintConfig, formatFiles()]);
+}