Migrate to eslint v9

Author: ben12

.eslintrc.js

@@ -12,7 +12,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
     - name: Install Node.js
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v4
       with:
         node-version: 18.x
         registry-url: "https://registry.npmjs.org"

.github/workflows/CD.yml

@@ -16,7 +16,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
     - name: Install Node.js
-      uses: actions/setup-node@v3
+      uses: actions/setup-node@v4
       with: { node-version: 18.x }
     - name: Install Packages
       run: npm ci
@@ -28,28 +28,38 @@ jobs:
 
     strategy:
       matrix:
-        eslint: [8.x]
+        eslint: [9.x]
+        typescript-eslint: [8.x]
         node: [20.x]
         os: [ubuntu-latest]
         include:
         # On other platforms
-        - eslint: 8.x
+        - eslint: 9.x
+          typescript-eslint: [8.x]
           node: 20.x
           os: windows-latest
-        - eslint: 8.x
+        - eslint: 9.x
+          typescript-eslint: [8.x]
           node: 20.x
           os: macos-latest
         # On old Node.js versions
         - eslint: 8.x
+          typescript-eslint: [6.x]
           node: 18.x
           os: ubuntu-latest
         - eslint: 8.x
+          typescript-eslint: [6.x]
           node: 16.x
           os: ubuntu-latest
-        # On old ESLint versions
+        # Other ESLint versions
         - eslint: 7.x
+          typescript-eslint: [6.x]
           node: 18.x
           os: ubuntu-latest
+        - eslint: 8.x
+          typescript-eslint: [6.x]
+          node: 20.x
+          os: ubuntu-latest
 
     runs-on: ${{ matrix.os }}
     steps:
@@ -60,10 +70,10 @@ jobs:
       with: { node-version: "${{ matrix.node }}" }
     - name: Install Packages
       run: npm install
-    - name: Install ESLint ${{ matrix.eslint }}
-      run: npm install --no-save eslint@${{ matrix.eslint }}
+    - name: Install ESLint ${{ matrix.eslint }} and TypeScript-ESLint ${{ matrix.typescript-eslint }}
+      run: npm install --force --no-save eslint@${{ matrix.eslint }} @typescript-eslint/eslint-plugin@${{ matrix.typescript-eslint }}
     - name: Test
-      run: npm run -s test:ci -- --reporter json --reporter-options output=reports/tests.json
+      run: npm run -s test:ci:${{ matrix.eslint }} -- --reporter json --reporter-options output=reports/tests.json
     - name: Test Report
       uses: dorny/test-reporter@v1
       if: success() || failure()

.github/workflows/CI.yml

@@ -38,6 +38,49 @@ $ npm install -D @dprint/typescript
 
 Write your ESLint configuration. For example with typescript code:
 
+From eslint v9 (flat configuration)
+
+```mjs
+import tsPlugin from "@typescript-eslint/eslint-plugin";
+import tsParser from "@typescript-eslint/parser";
+import dprint from "@ben_12/eslint-plugin-dprint";
+
+module.exports = {
+  files: ["**/*.ts", "**/*.js"],
+
+  languageOptions: {
+      parser: tsParser
+  },
+
+  plugins: {
+      "@typescript-eslint": tsPlugin,
+      "@ben_12/dprint": dprint,
+  },
+
+  rules: {
+    ...tsPlugin.configs["eslint-recommended"].rules,
+    ...tsPlugin.configs["recommended"].rules,
+    ...tsPlugin.configs["strict"].rules,
+    ...dprint.configs["typescript-recommended"].rules
+    "@ben_12/dprint/typescript": [
+      "error",
+      {
+        // Use dprint JSON configuration file (default: "dprint.json")
+        // It may be created using `dprint init` command
+        // See also https://dprint.dev/config/
+        configFile: "dprint.json",
+        config: {
+          // The TypeScript configuration of dprint
+          // See also https://dprint.dev/plugins/typescript/config/
+        },
+      },
+    ],
+  },
+};
+```
+
+For old eslint (eslintrc configuration)
+
 ```js
 module.exports = {
   extends: ["eslint:recommended", "plugin:@typescript-eslint/recommended", "plugin:@ben_12/dprint/typescript-recommended"],

README.md

@@ -0,0 +1,42 @@
+import tsPlugin from "@typescript-eslint/eslint-plugin";
+import tsParser from "@typescript-eslint/parser";
+import simpleParser from "@ben_12/eslint-simple-parser";
+import dprint from "@ben_12/eslint-plugin-dprint";
+
+
+export default [{
+    ignores: ["**/.eslintrc.js", ".nyc_output", "coverage", "dist"],
+}, {
+    files: ["**/*.ts", "**/*.js"],
+
+    plugins: {
+        "@typescript-eslint": tsPlugin,
+        "@ben_12/dprint": dprint,
+    },
+
+    languageOptions: {
+        parser: tsParser,
+        ecmaVersion: 5,
+        sourceType: "module",
+    },
+
+    rules: {
+        ...tsPlugin.configs["eslint-recommended"].rules,
+        ...tsPlugin.configs["recommended"].rules,
+        ...tsPlugin.configs["strict"].rules,
+        ...dprint.configs["typescript-recommended"].rules
+    }
+}, {
+    files: ["**/*.md"],
+
+    plugins: {
+        "@ben_12/dprint": dprint,
+    },
+
+    languageOptions: {
+        parser: simpleParser,
+    },
+
+    rules: dprint.configs["markdown-recommended"].rules
+
+}];

eslint.config.mjs

@@ -1,4 +1,4 @@
-/* eslint-disable @typescript-eslint/no-var-requires */
+/* eslint-disable @typescript-eslint/no-require-imports */
 
 import { createFromBuffer, Formatter } from "@dprint/formatter"
 import * as fs from "fs"
@@ -35,7 +35,8 @@ for (const module of plugins) {
             const formatter = createFromBuffer(buffer)
             formatters.push(formatter)
         }
-    } catch (e) {
+    } // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    catch (e) {
         // plugin unavailable
     }
 }