style: add eslint (#237)

See https://eslint.org/.

Added the default "recommended" rules. Turned off failing rules to make
the integration easier

Author: danielpza

.github/workflows/main.yml

@@ -3,7 +3,7 @@ name: Node.js CI
 on: [push]
 
 jobs:
-  prettier:
+  lint:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -14,7 +14,7 @@ jobs:
           cache: yarn
           cache-dependency-path: "**/yarn.lock"
       - run: yarn install
-      - run: yarn prettier --check .
+      - run: yarn lint
 
   build:
     runs-on: ${{ matrix.os }}

README.md

@@ -199,7 +199,7 @@ import "normally-transformed"; // This will remain 'normally-transformed', even
 ## Project Guidelines for Contributors
 
 - Package Manager: `yarn` (`yarn install`)
-- Format before commit: `prettier` (`yarn format`)
+- Format and lint the code before commit: `prettier` (`yarn format && yarn lint`)
 - Commit messages: [Conventional Commit Specs](https://www.conventionalcommits.org/en/v1.0.0/)
 - Releases: `changelogen` (`yarn release`)
 

eslint.config.mjs

@@ -0,0 +1,28 @@
+import globals from "globals";
+import pluginJs from "@eslint/js";
+import tseslint from "typescript-eslint";
+
+export default [
+  { files: ["**/*.{js,mjs,cjs,ts}"] },
+  { ignores: ["**/dist/", "src/declarations/", "test/projects/"] },
+  { languageOptions: { globals: globals.node } },
+  pluginJs.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    rules: {
+      "@typescript-eslint/ban-ts-comment": "warn",
+      "@typescript-eslint/no-empty-object-type": "warn",
+      "@typescript-eslint/no-explicit-any": "off",
+      "@typescript-eslint/no-namespace": "warn",
+      "@typescript-eslint/no-require-imports": "off",
+      "@typescript-eslint/no-unsafe-function-type": "warn",
+      "@typescript-eslint/no-unused-vars": "warn",
+      "no-case-declarations": "warn",
+      "no-empty": "warn",
+      "no-useless-escape": "warn",
+      "prefer-const": "off",
+      "prefer-rest-params": "warn",
+      "prefer-spread": "warn",
+    },
+  },
+];

package.json

@@ -11,6 +11,7 @@
     "release": "changelogen --release --push",
     "--------------": "",
     "format": "prettier --write .",
+    "lint": "prettier --check . && eslint .",
     "clean": "rm -rf \"**/dist\"",
     "clean:all": "yarn clean && rm -rf node_modules \"**/node_modules\" \"**/yarn.lock\" yarn.lock",
     "reset": "yarn clean:all && yarn install && yarn build",
@@ -53,15 +54,20 @@
     "nx-transformer.js"
   ],
   "devDependencies": {
+    "@eslint/js": "^9.8.0",
     "@tsconfig/node18": "^18.2.4",
+    "@types/eslint": "^9",
     "@types/minimatch": "^5.1.2",
     "@types/node": "^18.19.43",
     "@types/ts-expose-internals": "npm:[email protected]",
     "@types/ts-node": "npm:ts-node@^10.9.2",
     "changelogen": "^0.5.5",
+    "eslint": "9.x",
+    "globals": "^15.9.0",
     "prettier": "^3.3.3",
     "ts-patch": "^3.2.1",
-    "typescript": "^5.5.4"
+    "typescript": "^5.5.4",
+    "typescript-eslint": "^8.0.1"
   },
   "peerDependencies": {
     "typescript": ">=3.6.5"