Add tests for detecting whether an environment erroneously considers a prototype enumerable

kgryte · kgryte · commit ca4eb4b725df · 2018-05-01T09:45:36.000-07:00
diff --git a/lib/node_modules/@stdlib/utils/keys/test/test.has_enumerable_prototype_bug.js b/lib/node_modules/@stdlib/utils/keys/test/test.has_enumerable_prototype_bug.js
@@ -0,0 +1,67 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2018 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var tape = require( 'tape' );
+var proxyquire = require( 'proxyquire' );
+var isEnumerableProperty = require( '@stdlib/assert/is-enumerable-property' );
+var bool = require( './../lib/has_enumerable_prototype_bug.js' );
+
+
+// TESTS //
+
+tape( 'main export is a boolean', function test( t ) {
+	t.ok( true, __filename );
+	t.strictEqual( typeof bool, 'boolean', 'main export is a boolean' );
+	t.end();
+});
+
+tape( 'the exported value is `true` if an environment treats a value\'s prototype as enumerable', function test( t ) {
+	var bool = proxyquire( './../lib/has_enumerable_prototype_bug.js', {
+		'@stdlib/assert/is-enumerable-property': mock
+	});
+
+	t.strictEqual( bool, true, 'returns expected value' );
+	t.end();
+
+	function mock( obj, prop ) {
+		if ( prop === 'prototype' ) {
+			return true;
+		}
+		return isEnumerableProperty( obj, prop );
+	}
+});
+
+tape( 'the exported value is `false` if an environment does not treat a value\'s prototype as enumerable', function test( t ) {
+	var bool = proxyquire( './../lib/has_enumerable_prototype_bug.js', {
+		'@stdlib/assert/is-enumerable-property': mock
+	});
+
+	t.strictEqual( bool, false, 'returns expected value' );
+	t.end();
+
+	function mock( obj, prop ) {
+		if ( prop === 'prototype' ) {
+			return false;
+		}
+		return isEnumerableProperty( obj, prop );
+	}
+});
