feat: generate .d.ts files on publishing

Fixes #24

.gitignore

@@ -1 +1,3 @@
 node_modules
+index.d.ts
+skip-formatting.d.ts

index.js

@@ -1,5 +1,6 @@
 const recommendedConfig = require("eslint-plugin-prettier/recommended");
 
+/** @type {import('eslint').Linter.Config} */
 module.exports = {
   ...recommendedConfig,
   rules: {

package.json

@@ -6,7 +6,9 @@
   "main": "index.js",
   "files": [
     "index.js",
-    "skip-formatting.js"
+    "index.d.ts",
+    "skip-formatting.js",
+    "skip-formatting.d.ts"
   ],
   "exports": {
     ".": "./index.js",
@@ -38,14 +40,16 @@
   },
   "devDependencies": {
     "eslint": "^9.11.0",
-    "prettier": "^3.3.3"
+    "prettier": "^3.3.3",
+    "typescript": "^5.6.3"
   },
   "peerDependencies": {
     "eslint": ">= 8.21.0",
     "prettier": ">= 3.0.0"
   },
   "scripts": {
     "lint": "eslint . --fix",
-    "format": "prettier *.{js,md} --write"
+    "format": "prettier *.{js,md} --write",
+    "prepublishOnly": "tsc"
   }
 }

skip-formatting.js

@@ -4,6 +4,8 @@ const eslintConfigPrettier = require("eslint-config-prettier");
 // Because that would be an overkill:
 // - since we are not formatting, the plugin isn't needed;
 // - and without the `prettier/prettier` rule, we don't have to disable the conflicting `arrow-body-style` and `prefer-arrow-callback` rules.
+
+/** @type {import('eslint').Linter.Config} */
 module.exports = {
   ...eslintConfigPrettier,
   rules: {

tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "include": ["index.js", "skip-formatting.js"],
+  "compilerOptions": {
+    "allowJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "skipLibCheck": true
+  }
+}