[New] add types

Author: ljharb

index.d.ts

@@ -0,0 +1,3 @@
+declare function isWeakRef<T extends object>(value: unknown): value is WeakRef<T>;
+
+export = isWeakRef;

index.js

@@ -4,8 +4,9 @@ var callBound = require('call-bound');
 
 var $deref = callBound('WeakRef.prototype.deref', true);
 
+/** @type {import('.')} */
 module.exports = typeof WeakRef === 'undefined'
-	? function isWeakRef(value) { // eslint-disable-line no-unused-vars
+	? function isWeakRef(_value) { // eslint-disable-line no-unused-vars
 		return false;
 	}
 	: function isWeakRef(value) {

package.json

@@ -15,6 +15,7 @@
 		"prepublishOnly": "safe-publish-latest",
 		"prepublish": "not-in-publish || npm run prepublishOnly",
 		"lint": "eslint --ext=js,mjs .",
+		"postlint": "tsc && attw -P",
 		"pretest": "npm run lint",
 		"tests-only": "nyc tape 'test/**/*.js'",
 		"test": "npm run tests-only",
@@ -41,7 +42,12 @@
 	},
 	"homepage": "https://github.com/inspect-js/is-weakref#readme",
 	"devDependencies": {
+		"@arethetypeswrong/cli": "^0.17.1",
 		"@ljharb/eslint-config": "^21.1.1",
+		"@ljharb/tsconfig": "^0.2.2",
+		"@types/for-each": "^0.3.3",
+		"@types/object-inspect": "^1.13.0",
+		"@types/tape": "^5.6.5",
 		"auto-changelog": "^2.5.0",
 		"encoding": "^0.1.13",
 		"eslint": "=8.8.0",
@@ -51,7 +57,8 @@
 		"nyc": "^10.3.2",
 		"object-inspect": "^1.13.3",
 		"safe-publish-latest": "^2.0.0",
-		"tape": "^5.9.0"
+		"tape": "^5.9.0",
+		"typescript": "next"
 	},
 	"dependencies": {
 		"call-bound": "^1.0.2"

tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "@ljharb/tsconfig",
+  "compilerOptions": {
+    "target": "ES2021",
+  },
+  "exclude": [
+    "coverage"
+  ]
+}