chore: add lint-staged (#6)

.husky/pre-commit

@@ -1,3 +1 @@
-npm run format
-npm run typecheck
-npm run lint
+npx lint-staged

lint-staged.config.js

@@ -0,0 +1,9 @@
+export default {
+  // The Typescript compiler can't type-check a single file, it needs to run on
+  // the whole project. To do that we use a function (instead of a string or
+  // array) so that no matter what file or how many, we will always run the same
+  // command.
+  "*.{ts,tsx}": () => "tsc --noEmit",
+  "*.{ts,tsx,js,jsx}": ["eslint --fix", "prettier --write"],
+  "*": "prettier --ignore-unknown --write",
+};

package.json

@@ -42,7 +42,7 @@
   "scripts": {
     "prepare": "husky",
     "build": "tsup-node",
-    "format": "prettier --write .",
+    "format": "prettier --write src",
     "typecheck": "tsc",
     "lint": "eslint --quiet .",
     "test": "vitest run",
@@ -58,6 +58,7 @@
     "eslint": "^9.13.0",
     "hono": "^4.6.6",
     "husky": "^9.1.6",
+    "lint-staged": "^15.2.10",
     "prettier": "^3.3.3",
     "tsup": "^8.3.0",
     "typescript-eslint": "^8.11.0",