[New] add types

Author: ljharb

index.d.ts

@@ -0,0 +1,3 @@
+declare function hasStrictMode(): boolean;
+
+export = hasStrictMode;

index.js

@@ -1,5 +1,6 @@
 'use strict';
 
+/** @type {import('.')} */
 module.exports = function hasStrictMode() {
 	return !this;
 };

package.json

@@ -9,6 +9,7 @@
 		"prepublish": "not-in-publish || npm run prepublishOnly",
 		"pretest": "npm run lint",
 		"lint": "eslint --ext=js,mjs .",
+		"postlint": "tsc && attw -P",
 		"tests-only": "nyc tape 'test/**/*.js'",
 		"test": "npm run tests-only",
 		"posttest": "npx npm@\">= 10.2\" audit --production",
@@ -37,15 +38,19 @@
 	},
 	"homepage": "https://github.com/inspect-js/has-strict-mode#readme",
 	"devDependencies": {
+		"@arethetypeswrong/cli": "^0.17.3",
 		"@ljharb/eslint-config": "^21.1.1",
+		"@ljharb/tsconfig": "^0.2.3",
+		"@types/tape": "^5.8.1",
 		"auto-changelog": "^2.5.0",
 		"encoding": "^0.1.13",
 		"eslint": "=8.8.0",
 		"in-publish": "^2.0.1",
 		"npmignore": "^0.3.1",
 		"nyc": "^10.3.2",
 		"safe-publish-latest": "^2.0.0",
-		"tape": "^5.9.0"
+		"tape": "^5.9.0",
+		"typescript": "next"
 	},
 	"auto-changelog": {
 		"output": "CHANGELOG.md",

tsconfig.json

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