chore: bumped ESLint and Prettier devDeps to latest (flat config) (#271)

* chore: bumped ESLint and Prettier devDeps to latest (flat config)

* split lint into separate task

* fix typo: npm 'run' lint

* No more ||= (logical-assignment-operators)

Author: JoshuaKGoldberg

.eslintignore

@@ -8,6 +8,25 @@ permissions:
   contents: read
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    name: node lint
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: setup node 22
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: 22
+
+      - name: npm ci
+        run: npm ci
+
+      - run: npm run lint
+
   test:
     runs-on: ubuntu-latest
 
@@ -16,7 +35,7 @@ jobs:
       matrix:
         node-version: [ 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 ]
 
-    name: node v${{ matrix.node-version }} build
+    name: node v${{ matrix.node-version }} test
 
     steps:
       - name: checkout

.github/workflows/build.yml

@@ -40,7 +40,7 @@ module.exports = class extends Generator {
         message: 'Your generator name',
         default: makeGeneratorName(path.basename(process.cwd())),
         filter: makeGeneratorName,
-        validate: str => {
+        validate(str) {
           return str.length > 'generator-'.length;
         }
       },

app/index.js

@@ -0,0 +1,37 @@
+const { defineConfig } = require('eslint/config');
+const xo = require('eslint-config-xo');
+const configPrettier = require('eslint-config-prettier/flat');
+const eslintPluginPrettierRecommended = require('eslint-plugin-prettier/recommended');
+const globals = require('globals');
+
+module.exports = defineConfig([
+  { ignores: ['app/templates', 'coverage', 'node_modules'] },
+  { rules: xo.rules },
+  configPrettier,
+  eslintPluginPrettierRecommended,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.jest,
+        ...globals.node
+      }
+    },
+    linterOptions: {
+      reportUnusedDisableDirectives: 'error'
+    },
+    rules: {
+      // Only supported in Node >=15; we still support >=10 for now
+      'logical-assignment-operators': 'off',
+
+      'prettier/prettier': [
+        'error',
+        {
+          arrowParens: 'avoid',
+          printWidth: 90,
+          singleQuote: true,
+          trailingComma: 'none'
+        }
+      ]
+    }
+  }
+]);