Add polyfill tests

Author: kgryte

lib/node_modules/@stdlib/utils/keys/lib/polyfill.js

@@ -50,39 +50,38 @@ var NON_ENUMERABLE = require( './non_enumerable.json' );
 function keys( value ) {
 	var skipConstructor;
 	var skipPrototype;
-	var isArgs;
 	var isFcn;
 	var out;
 	var k;
 	var p;
 	var i;
 
 	out = [];
+	if ( isArguments( value ) ) {
+		// Account for environments which treat `arguments` differently...
+		for ( i = 0; i < value.length; i++ ) {
+			out.push( i.toString() );
+		}
+		// Note: yes, we are precluding the `arguments` array-like object from having other enumerable properties; however, this should (1) be very rare and (2) not be encouraged (e.g., doing something like `arguments.a = 'b'`; in certain engines directly manipulating the `arguments` value results in automatic de-optimization).
+		return out;
+	}
 	if ( typeof value === 'string' ) {
 		// Account for environments which do not treat string character indices as "own" properties...
 		if ( value.length > 0 && !hasOwnProp( value, '0' ) ) {
 			for ( i = 0; i < value.length; i++ ) {
 				out.push( i.toString() );
 			}
 		}
-	} else if ( isArguments( value ) ) {
-		// Account for environments which treat `arguments` differently...
-		isArgs = true;
-		for ( i = 0; i < value.length; i++ ) {
-			out.push( i.toString() );
-		}
 	} else {
 		isFcn = ( typeof value === 'function' );
 		if ( isFcn === false && !isObjectLike( value ) ) {
 			return out;
 		}
 		skipPrototype = ( HAS_ENUM_PROTO_BUG && isFcn );
 	}
-	if ( isArgs === void 0 ) {
-		for ( k in value ) {
-			if ( !( skipPrototype && k === 'prototype' ) && hasOwnProp( value, k ) ) {
-				out.push( String( k ) );
-			}
+	for ( k in value ) {
+		if ( !( skipPrototype && k === 'prototype' ) && hasOwnProp( value, k ) ) {
+			out.push( String( k ) );
 		}
 	}
 	if ( HAS_NON_ENUM_PROPS_BUG ) {

lib/node_modules/@stdlib/utils/keys/test/test.polyfill.js

@@ -21,8 +21,10 @@
 // MODULES //
 
 var tape = require( 'tape' );
+var proxyquire = require( 'proxyquire' );
 var indexOf = require( '@stdlib/utils/index-of' );
 var hasSymbolSupport = require( '@stdlib/assert/has-symbol-support' );
+var hasOwnProp = require( '@stdlib/assert/has-own-property' );
 var objectKeys = require( './../lib/polyfill.js' );
 
 
@@ -95,6 +97,145 @@ tape( 'the function returns an array of an object\'s own enumerable property nam
 	t.end();
 });
 
+tape( 'the function returns an array of an object\'s own enumerable property names (string; non-enumerable character indices)', function test( t ) {
+	var objectKeys;
+	var expected;
+	var actual;
+	var idx;
+	var i;
+
+	objectKeys = proxyquire( './../lib/polyfill.js', {
+		'@stdlib/assert/has-own-property': mock
+	});
+
+	expected = [ '0', '1', '2' ];
+	actual = objectKeys( 'foo' );
+
+	for ( i = 0; i < expected.length; i++ ) {
+		idx = indexOf( actual, expected[ i ] );
+		t.strictEqual( idx !== -1, true, 'contains property name: '+expected[i] );
+	}
+	t.end();
+
+	function mock( obj, prop ) {
+		if ( obj === 'foo' ) {
+			return false;
+		}
+		return hasOwnProp( obj, prop );
+	}
+});
+
+tape( 'the function returns an array of an object\'s own enumerable property names (function; environments having enumerable prototype bug)', function test( t ) {
+	var objectKeys;
+	var expected;
+	var actual;
+
+	function noop() {
+		// No-op...
+	}
+
+	noop.a = 'b';
+
+	objectKeys = proxyquire( './../lib/polyfill.js', {
+		'./has_enumerable_prototype_bug.js': true
+	});
+
+	expected = [ 'a' ];
+	actual = objectKeys( noop );
+
+	t.deepEqual( actual, expected, 'returns expected value' );
+	t.end();
+});
+
+tape( 'the function returns an array of an object\'s own enumerable property names (environments having non-enumerable properties bug)', function test( t ) {
+	var objectKeys;
+	var expected;
+	var actual;
+	var FLG;
+	var obj;
+	var idx;
+	var i;
+
+	FLG = true;
+
+	objectKeys = proxyquire( './../lib/polyfill.js', {
+		'./has_non_enumerable_properties_bug.js': true,
+		'@stdlib/assert/has-own-property': mock
+	});
+
+	obj = {
+		'a': 'b',
+		'toString': toString
+	};
+	expected = [ 'a', 'toString' ];
+	actual = objectKeys( obj );
+
+	for ( i = 0; i < expected.length; i++ ) {
+		idx = indexOf( actual, expected[ i ] );
+		t.strictEqual( idx !== -1, true, 'contains property name: '+expected[i] );
+	}
+	t.end();
+
+	function toString() {
+		return 'beep';
+	}
+
+	function mock( obj, prop ) {
+		if ( prop === 'toString' && hasOwnProp( obj, prop ) ) {
+			FLG = !FLG;
+			return FLG;
+		}
+		return hasOwnProp( obj, prop );
+	}
+});
+
+tape( 'the function returns an array of an object\'s own enumerable property names (environments having non-enumerable properties and constructor equality bugs)', function test( t ) {
+	var objectKeys;
+	var expected;
+	var actual;
+	var FLG;
+	var obj;
+	var idx;
+	var i;
+
+	FLG = true;
+
+	objectKeys = proxyquire( './../lib/polyfill.js', {
+		'./has_non_enumerable_properties_bug.js': true,
+		'@stdlib/assert/has-own-property': mock
+	});
+
+	obj = {
+		'a': 'b',
+		'toString': toString,
+		'constructor': {
+			'prototype': null
+		}
+	};
+	obj.constructor.prototype = obj; // circular
+
+	expected = [ 'a', 'toString' ];
+	actual = objectKeys( obj );
+
+	for ( i = 0; i < expected.length; i++ ) {
+		idx = indexOf( actual, expected[ i ] );
+		t.strictEqual( idx !== -1, true, 'contains property name: '+expected[i] );
+	}
+	t.end();
+
+	function toString() {
+		return 'beep';
+	}
+
+	function mock( obj, prop ) {
+		if ( prop === 'toString' && hasOwnProp( obj, prop ) ) {
+			FLG = !FLG;
+			return FLG;
+		}
+		return hasOwnProp( obj, prop );
+	}
+});
+
 tape( 'the function ignores non-enumerable properties', function test( t ) {
 	var expected;
 	var actual;