Tests

.eslintrc

@@ -1,5 +1,15 @@
 {
 	"root": true,
 
-	"extends": "@ljharb"
+	"extends": "@ljharb",
+
+	"overrides": [
+		{
+			"files": "test/**",
+			"globals": {
+				"WeakMap": false,
+				"WeakSet": false,
+			},
+		},
+	],
 }

package.json

@@ -6,7 +6,9 @@
 	"scripts": {
 		"pretest": "npm run lint",
 		"lint": "eslint .",
-		"test": "echo \"Error: no test specified\" && exit 1"
+		"tests-only": "node test",
+		"posttests-only": "node -e \"require('es5-shim'); require('es6-shim'); require('./test');\"",
+		"test": "npm run tests-only"
 	},
 	"repository": {
 		"type": "git",
@@ -27,6 +29,11 @@
 	"homepage": "https://github.com/inspect-js/is-set#readme",
 	"devDependencies": {
 		"@ljharb/eslint-config": "^15.0.1",
-		"eslint": "^6.6.0"
+		"es5-shim": "^4.5.13",
+		"es6-shim": "^0.35.5",
+		"eslint": "^6.6.0",
+		"for-each": "^0.3.3",
+		"object-inspect": "^1.7.0",
+		"tape": "^4.11.0"
 	}
 }

test/index.js

@@ -0,0 +1,59 @@
+'use strict';
+
+var test = require('tape');
+var debug = require('object-inspect');
+var forEach = require('for-each');
+
+var isSet = require('..');
+
+test('non-collections', function (t) {
+	forEach([
+		null,
+		undefined,
+		true,
+		false,
+		42,
+		0,
+		-0,
+		NaN,
+		Infinity,
+		'',
+		'foo',
+		/a/g,
+		[],
+		{},
+		function () {}
+	], function (nonCollection) {
+		t.equal(isSet(nonCollection), false, debug(nonCollection) + ' is not a Set');
+	});
+
+	t.end();
+});
+
+test('Maps', { skip: typeof Map !== 'function' }, function (t) {
+	var m = new Map();
+	t.equal(isSet(m), false, debug(m) + ' is not a Set');
+
+	t.end();
+});
+
+test('Sets', { skip: typeof Set !== 'function' }, function (t) {
+	var s = new Set();
+	t.equal(isSet(s), true, debug(s) + ' is a Set');
+
+	t.end();
+});
+
+test('WeakMaps', { skip: typeof WeakMap !== 'function' }, function (t) {
+	var wm = new WeakMap();
+	t.equal(isSet(wm), false, debug(wm) + ' is not a Set');
+
+	t.end();
+});
+
+test('WeakSets', { skip: typeof WeakSet !== 'function' }, function (t) {
+	var ws = new WeakSet();
+	t.equal(isSet(ws), false, debug(ws) + ' is not a Set');
+
+	t.end();
+});