Support cross-realm URL and Date

lib/chai-subset.js

@@ -12,6 +12,7 @@
 	})(function(chai, utils) {
 		var Assertion = chai.Assertion;
 		var assertionPrototype = Assertion.prototype;
+		var toString = Object.prototype.toString;
 
 		Assertion.addMethod('containSubset', function (expected) {
 			var actual = utils.flag(this, 'object');
@@ -57,14 +58,22 @@
 				});
 			}
 
-			if (expected instanceof Date) {
-				if (actual instanceof Date) {
+			if (toString.call(expected) === '[object Date]') {
+				if (toString.call(actual) === '[object Date]') {
 					return expected.getTime() === actual.getTime();
 				} else {
 					return false;
 				}
 			}
 
+			if (toString.call(expected) === '[object URL]') {
+				if (toString.call(actual) === '[object URL]') {
+					return expected.href === actual.href;
+				} else {
+					return false;
+				}
+			}
+
 			return Object.keys(expected).every(function (key) {
 				var eo = expected[key];
 				var ao = actual[key];

package.json

@@ -41,7 +41,8 @@
     "coveralls": "2.11.16",
     "istanbul": "0.4.5",
     "mocha": "3.2.0",
-    "mocha-eslint": "3.0.1"
+    "mocha-eslint": "3.0.1",
+    "universal-url": "^1.0.0-alpha"
   },
   "files": [
     "lib"

test/unit/chai-subset.spec.js

@@ -173,6 +173,26 @@ describe('comparison of dates', function() {
 	});
 });
 
+describe('comparison of urls', function() {
+	const URL = require('universal-url').URL;
+
+	it('should pass for the same url', function() {
+		expect(new URL('http://host/')).to.containSubset(new URL('http://host/'));
+	});
+
+	it('should pass for the same url if nested', function() {
+		expect({a: new URL('http://host/')}).to.containSubset({a: new URL('http://host/')});
+	});
+
+	it('should fail for a different url', function() {
+		expect(new URL('http://host1/')).to.not.containSubset(new URL('http://host2/'));
+	});
+
+	it('should fail for a different url if nested', function() {
+		expect({a: new URL('http://host1/')}).to.not.containSubset({a: new URL('http://host2/')});
+	});
+});
+
 describe('cyclic objects', () => {
 	it('should pass', () => {
 		const child = {};