text: /**
  * @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 indexOf = require( './../../index-of' );
  var defineProperty = require( './../../define-property' );
  var hasSymbolSupport = require( '@stdlib/assert/has-symbol-support' );
  var Symbol = require( '@stdlib/symbol/ctor' );
  var writablePropertySymbolsIn = require( './../lib' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.strictEqual( typeof writablePropertySymbolsIn, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function returns an array of an object\'s own and inherited writable symbol properties', function test( t ) {
  	var hasSymbols;
  	var expected;
  	var actual;
  	var syms;
  	var obj;
  	var idx;
  	var i;
  
  	hasSymbols = hasSymbolSupport();
  
  	function Foo() {
  		if ( hasSymbols ) {
  			this[ syms[ 0 ] ] = 'boop';
  			this[ syms[ 1 ] ] = {
  				'b': 'c'
  			};
  			defineProperty( this, syms[ 2 ], {
  				'configurable': false,
  				'enumerable': true,
  				'writable': false,
  				'value': 'e'
  			});
  			defineProperty( this, syms[ 3 ], {
  				'configurable': true,
  				'enumerable': false,
  				'writable': false,
  				'value': 'g'
  			});
  			defineProperty( this, syms[ 4 ], {
  				'configurable': false,
  				'enumerable': true,
  				'writable': false,
  				'value': 'i'
  			});
  		}
  		return this;
  	}
  
  	if ( hasSymbols ) {
  		syms = [
  			Symbol( 'beep' ),
  			Symbol( 'a' ),
  			Symbol( 'd' ),
  			Symbol( 'f' ),
  			Symbol( 'h' ),
  			Symbol( 'foo' ),
  			Symbol( 'baz' )
  		];
  
  		defineProperty( Foo.prototype, syms[ 3 ], {
  			'configurable': true,
  			'enumerable': true,
  			'writable': true,
  			'value': 'g'
  		});
  		Foo.prototype[ syms[ 5 ] ] = [ 'bar' ];
  		defineProperty( Foo.prototype, syms[ 6 ], {
  			'configurable': false,
  			'enumerable': true,
  			'writable': false,
  			'value': 'bap'
  		});
  
  		obj = new Foo();
  
  		expected = [ syms[ 0 ], syms[ 1 ], syms[ 5 ] ];
  	} else {
  		syms = [];
  		expected = [];
  	}
  	actual = writablePropertySymbolsIn( obj );
  
  	t.strictEqual( actual.length, expected.length, 'has expected length' );
  	for ( i = 0; i < expected.length; i++ ) {
  		idx = indexOf( actual, expected[ i ] );
  		t.strictEqual( idx !== -1, true, 'contains property name: '+expected[i].toString() );
  	}
  	t.end();
  });
  
  tape( 'the function returns an array of an object\'s own and inherited writable symbol properties (mock)', function test( t ) {
  	var writablePropertySymbolsIn;
  	var expected;
  	var actual;
  	var syms;
  	var obj;
  	var idx;
  	var i;
  
  	writablePropertySymbolsIn = proxyquire( './../lib/main.js', {
  		'./../../property-symbols': propertySymbols
  	});
  
  	syms = [
  		'__beep__',
  		'__a__',
  		'__d__',
  		'__f__',
  		'__h__',
  		'__foo__',
  		'__baz__'
  	];
  
  	function Foo() {
  		this[ syms[ 0 ] ] = 'boop';
  		this[ syms[ 1 ] ] = {
  			'b': 'c'
  		};
  		defineProperty( this, syms[ 2 ], {
  			'configurable': false,
  			'enumerable': true,
  			'writable': false,
  			'value': 'e'
  		});
  		defineProperty( this, syms[ 3 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': false,
  			'value': 'g'
  		});
  		defineProperty( this, syms[ 4 ], {
  			'configurable': false,
  			'enumerable': true,
  			'writable': false,
  			'value': 'i'
  		});
  		return this;
  	}
  
  	defineProperty( Foo.prototype, syms[ 3 ], {
  		'configurable': true,
  		'enumerable': true,
  		'writable': true,
  		'value': 'g'
  	});
  	Foo.prototype[ syms[ 5 ] ] = [ 'bar' ];
  	defineProperty( Foo.prototype, syms[ 6 ], {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'bap'
  	});
  
  	obj = new Foo();
  
  	expected = [ syms[ 0 ], syms[ 1 ], syms[ 5 ] ];
  	actual = writablePropertySymbolsIn( obj );
  
  	t.strictEqual( actual.length, expected.length, 'has expected length' );
  	for ( i = 0; i < expected.length; i++ ) {
  		idx = indexOf( actual, expected[ i ] );
  		t.strictEqual( idx !== -1, true, 'contains property: '+expected[i].toString() );
  	}
  	t.end();
  
  	function propertySymbols( value ) {
  		if ( value === obj ) {
  			return syms.slice( 0, 5 );
  		}
  		if ( value === Foo.prototype ) {
  			return [ syms[ 3 ], syms[ 5 ], syms[ 6 ] ];
  		}
  		return [];
  	}
  });
  
  tape( 'the function returns an empty array if provided `null` or `undefined`', function test( t ) {
  	var expected;
  	var actual;
  	var values;
  	var i;
  
  	values = [
  		void 0,
  		null
  	];
  	expected = [];
  
  	for ( i = 0; i < values.length; i++ ) {
  		actual = writablePropertySymbolsIn( values[ i ] );
  		t.deepEqual( actual, expected, 'returns expected value when provided '+values[ i ] );
  	}
  	t.end();
  });
  
  tape( 'the function returns an empty array if provided a non-string primitive', function test( t ) {
  	var expected;
  	var actual;
  	var values;
  	var i;
  
  	values = [
  		3.14,
  		NaN,
  		true,
  		false
  	];
  	expected = [];
  
  	for ( i = 0; i < values.length; i++ ) {
  		actual = writablePropertySymbolsIn( values[ i ] );
  		t.deepEqual( actual, expected, 'returns expected value when provided '+values[ i ] );
  	}
  	t.end();
  });
  