feat: upgrade deps, move to ESLint flat config 🚀

Author: robertrossmann

.eslintrc.js

@@ -20,6 +20,10 @@
   "files.trimTrailingWhitespace": true,
   "typescript.tsdk": "node_modules/typescript/lib",
   "typescript.enablePromptUseWorkspaceTsdk": true,
-  "eslint.lintTask.options": "--cache --ext js,ts .",
+  "eslint.lintTask.options": "--cache --config eslint.config.mjs .",
+  "eslint.experimental.useFlatConfig": true,
+  "eslint.options": {
+    "overrideConfigFile": "eslint.config.mjs",
+  },
   "mochaExplorer.files": "{src,test}/**/*.test.js"
 }

.vscode/settings.json

@@ -0,0 +1,46 @@
+import * as os from 'os'
+import nodev20 from '@strv/eslint-config-node/v20'
+import nodeopt from '@strv/eslint-config-node/optional'
+import nodestyle from '@strv/eslint-config-node/style'
+import ts from '@strv/eslint-config-typescript'
+import tsoptional from '@strv/eslint-config-typescript/optional'
+import tsstyle from '@strv/eslint-config-typescript/style'
+import mocha from '@strv/eslint-config-mocha'
+
+const lbstyle = os.platform() === 'win32' ? 'windows' : 'unix'
+const globs = {
+  mjs: '**/*.mjs',
+  ts: '**/*.ts',
+  tests: '**/*.test.ts',
+}
+
+/** @type {Array<import("eslint").Linter.FlatConfig>} */
+const config = [
+  { linterOptions: {
+    reportUnusedDisableDirectives: true,
+  } },
+  { ignores: ['**/*.js', '**/*.d.ts', 'node_modules'] },
+  { files: [globs.ts, globs.mjs], ...nodev20 },
+  { files: [globs.ts, globs.mjs], ...nodeopt },
+  { files: [globs.ts, globs.mjs], ...nodestyle },
+
+  { files: [globs.ts], ...ts },
+  { files: [globs.ts], ...tsoptional },
+  { files: [globs.ts], ...tsstyle },
+
+  { files: [globs.tests], ...mocha },
+
+  // Any custom settings to be applied
+  { files: [globs.ts],
+    languageOptions: {
+      parserOptions: { project: './tsconfig.json' },
+    },
+    rules: {
+      // This repository is configured so that upon checkout, git should convert line endings to platform-specific
+      // defaults and convert them back to LF when checking in. As such, we must enforce CRLF endings on Windows,
+      // otherwise the lint task would fail on Windows systems.
+      'linebreak-style': ['error', lbstyle],
+    } },
+]
+
+export default config

eslint.config.mjs

@@ -2,6 +2,7 @@
 SHELL := sh
 export PATH := node_modules/.bin/:$(PATH)
 export NODE_OPTIONS := --trace-deprecation
+export ESLINT_USE_FLAT_CONFIG := true
 
 # On CI servers, use the `npm ci` installer to avoid introducing changes to the package-lock.json
 # On developer machines, prefer the generally more flexible `npm install`. 💪
@@ -52,7 +53,7 @@ coverage: coverage/lcov.info
 install: node_modules $(GITFILES)
 
 lint: force install
-	eslint --cache --ext js,ts $(ESLINT_FLAGS) .
+	eslint --cache --config eslint.config.mjs $(ESLINT_FLAGS) .
 	remark --quiet .
 
 test: force compile