[New] add types

Author: ljharb

index.d.ts

@@ -0,0 +1,3 @@
+declare function isBooleanObject(value: unknown): value is boolean | Boolean;
+
+export = isBooleanObject;

index.js

@@ -4,6 +4,7 @@ var callBound = require('call-bind/callBound');
 var $boolToStr = callBound('Boolean.prototype.toString');
 var $toString = callBound('Object.prototype.toString');
 
+/** @type {import('.')} */
 var tryBooleanObject = function booleanBrandCheck(value) {
 try {
 $boolToStr(value);
@@ -15,6 +16,7 @@ var tryBooleanObject = function booleanBrandCheck(value) {
 var boolClass = '[object Boolean]';
 var hasToStringTag = require('has-tostringtag/shams')();
 
+/** @type {import('.')} */
 module.exports = function isBoolean(value) {
 if (typeof value === 'boolean') {
 return true;

package.json

@@ -20,6 +20,7 @@
 "posttest": "npx npm@'>=10.2' audit --production",
 "prelint": "eclint check $(git ls-files | xargs find 2> /dev/null | grep -vE 'node_modules|\\.git')",
 "lint": "eslint --ext=js,mjs .",
+"postlint": "tsc -p . && attw -P",
 "version": "auto-changelog && git add CHANGELOG.md",
 "postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
 },
@@ -42,7 +43,12 @@
 "has-tostringtag": "^1.0.2"
 },
 "devDependencies": {
+"@arethetypeswrong/cli": "^0.17.0",
 "@ljharb/eslint-config": "^21.1.1",
+"@ljharb/tsconfig": "^0.2.0",
+"@types/call-bind": "^1.0.5",
+"@types/core-js": "^2.5.8",
+"@types/tape": "^5.6.5",
 "auto-changelog": "^2.5.0",
 "core-js": "^3.39.0",
 "eclint": "^2.8.1",
@@ -54,7 +60,8 @@
 "npmignore": "^0.3.1",
 "nyc": "^10.3.2",
 "safe-publish-latest": "^2.0.0",
-"tape": "^5.9.0"
+"tape": "^5.9.0",
+"typescript": "next"
 },
 "testling": {
 "files": "test.js",

test/index.js

@@ -6,6 +6,7 @@ var hasToStringTag = require('has-tostringtag/shams')();
 
 test('not Booleans', function (t) {
 t.test('primitives', function (st) {
+// @ts-expect-error
 st.notOk(isBoolean(), 'undefined is not Boolean');
 st.notOk(isBoolean(null), 'null is not Boolean');
 st.notOk(isBoolean(0), '0 is not Boolean');
@@ -30,6 +31,7 @@ test('not Booleans', function (t) {
 });
 
 test('@@toStringTag', { skip: !hasToStringTag }, function (t) {
+/** @type {{ toString(): unknown; valueOf(): unknown; [Symbol.toStringTag]?: string; }} */
 var fakeBoolean = {
 toString: function () { return 'true'; },
 valueOf: function () { return true; }

tsconfig.json

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