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 indexOf = require( '@stdlib/utils-index-of' );
  var defineProperty = require( '@stdlib/utils-define-property' );
  var inherit = require( '@stdlib/utils-inherit' );
  var hasSymbolSupport = require( '@stdlib/assert-has-symbol-support' );
  var Symbol = require( '@stdlib/symbol-ctor' );
  var inheritedWritableProperties = require( './../lib' ); // eslint-disable-line id-length
  
  
  // VARIABLES //
  
  var hasSymbols = hasSymbolSupport();
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.strictEqual( typeof inheritedWritableProperties, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function throws an error if not provided a positive integer for the inheritance level', function test( t ) {
  	var values;
  	var i;
  
  	values = [
  		'5',
  		-5,
  		0,
  		3.14,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		[],
  		{},
  		function noop() {}
  	];
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws an error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inheritedWritableProperties( {}, value );
  		};
  	}
  });
  
  tape( 'the function returns an array of an object\'s inherited writable properties', function test( t ) {
  	var expected;
  	var actual;
  	var syms;
  	var obj;
  	var idx;
  	var i;
  
  	if ( hasSymbols ) {
  		syms = [
  			Symbol( 'a' ),
  			Symbol( 'b' ),
  			Symbol( 'c' ),
  			Symbol( 'd' )
  		];
  	} else {
  		syms = [];
  	}
  
  	function Foo() {
  		this.a = 'a';
  		this.b = 'b';
  		defineProperty( this, 'c', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'c'
  		});
  		defineProperty( this, 'f', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'f'
  		});
  		if ( hasSymbols ) {
  			this[ syms[ 0 ] ] = 'a';
  			defineProperty( this, syms[ 1 ], {
  				'configurable': false,
  				'enumerable': false,
  				'writable': true,
  				'value': 'b'
  			});
  		}
  		return this;
  	}
  
  	Foo.prototype.d = 'd';
  	defineProperty( Foo.prototype, 'e', {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'e'
  	});
  	Foo.prototype.f = 'f';
  	if ( hasSymbols ) {
  		Foo.prototype[ syms[ 2 ] ] = 'c';
  		defineProperty( Foo.prototype, syms[ 3 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': false,
  			'value': 'd'
  		});
  	}
  
  	obj = new Foo();
  
  	expected = [ 'd' ];
  	if ( hasSymbols ) {
  		expected.push( syms[ 2 ] );
  	}
  	actual = inheritedWritableProperties( obj );
  
  	t.strictEqual( actual.length >= expected.length, true, '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();
  });
  
  tape( 'the function returns an array of an object\'s inherited writable properties (multiple inheritance)', function test( t ) {
  	var expected;
  	var actual;
  	var syms;
  	var obj;
  	var idx;
  	var i;
  
  	if ( hasSymbols ) {
  		syms = [
  			Symbol( 'a' ),
  			Symbol( 'b' ),
  			Symbol( 'c' ),
  			Symbol( 'd' ),
  			Symbol( 'e' ),
  			Symbol( 'f' )
  		];
  	} else {
  		syms = [];
  	}
  
  	function Bar() {
  		this.a = 'a';
  		defineProperty( this, 'd', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'd'
  		});
  		if ( hasSymbols ) {
  			this[ syms[ 0 ] ] = 'a';
  		}
  		return this;
  	}
  
  	Bar.prototype.b = 'b';
  	Bar.prototype.c = 'c';
  	defineProperty( Bar.prototype, 'd', {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'd'
  	});
  	defineProperty( Bar.prototype, 'f', {
  		'configurable': true,
  		'enumerable': false,
  		'writable': false,
  		'value': 'f'
  	});
  	if ( hasSymbols ) {
  		defineProperty( Bar.prototype, syms[ 2 ], {
  			'configurable': true,
  			'enumerable': false,
  			'writable': false,
  			'value': 'c'
  		});
  		defineProperty( Bar.prototype, syms[ 3 ], {
  			'configurable': true,
  			'enumerable': false,
  			'writable': true,
  			'value': 'd'
  		});
  		defineProperty( Bar.prototype, syms[ 4 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': false,
  			'value': 'e'
  		});
  	}
  
  	function Foo() {
  		Bar.call( this );
  		this.a = 'a';
  		this.b = 'b';
  		defineProperty( this, 'd', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'd'
  		});
  		if ( hasSymbols ) {
  			defineProperty( this, syms[ 1 ], {
  				'configurable': false,
  				'enumerable': false,
  				'writable': true,
  				'value': 'b'
  			});
  		}
  		return this;
  	}
  
  	inherit( Foo, Bar );
  
  	Foo.prototype.b = 'b';
  	defineProperty( Foo.prototype, 'e', {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'e'
  	});
  	defineProperty( Foo.prototype, 'f', {
  		'configurable': true,
  		'enumerable': true,
  		'writable': false,
  		'value': 'f'
  	});
  	if ( hasSymbols ) {
  		defineProperty( Foo.prototype, syms[ 2 ], {
  			'configurable': true,
  			'enumerable': true,
  			'writable': true,
  			'value': 'c'
  		});
  		defineProperty( Foo.prototype, syms[ 3 ], {
  			'configurable': true,
  			'enumerable': false,
  			'writable': false,
  			'value': 'd'
  		});
  		defineProperty( Foo.prototype, syms[ 5 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': false,
  			'value': 'f'
  		});
  	}
  
  	obj = new Foo();
  
  	expected = [ 'b', 'c' ];
  	if ( hasSymbols ) {
  		expected.push( syms[ 2 ] );
  	}
  	actual = inheritedWritableProperties( obj );
  
  	t.strictEqual( actual.length >= expected.length, true, '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() );
  	}
  	idx = indexOf( actual, 'f' );
  	t.strictEqual( idx, -1, 'does not contain property' );
  	if ( hasSymbols ) {
  		idx = indexOf( actual, syms[ 3 ] );
  		t.strictEqual( idx, -1, 'does not contain property' );
  	}
  	t.end();
  });
  
  tape( 'the function supports limiting the inheritance level', function test( t ) {
  	var expected;
  	var actual;
  	var syms;
  	var obj;
  	var idx;
  	var i;
  
  	if ( hasSymbols ) {
  		syms = [
  			Symbol( 'a' ),
  			Symbol( 'b' ),
  			Symbol( 'c' ),
  			Symbol( 'd' ),
  			Symbol( 'e' )
  		];
  	} else {
  		syms = [];
  	}
  
  	function Bar() {
  		this.boop = 'beep';
  		this.a = {
  			'b': 'c'
  		};
  		defineProperty( this, 'd', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'e'
  		});
  		if ( hasSymbols ) {
  			this[ syms[ 0 ] ] = 'a';
  		}
  		return this;
  	}
  
  	Bar.prototype.bar = [ 'foo' ];
  	defineProperty( Bar.prototype, 'bap', {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'baz'
  	});
  	if ( hasSymbols ) {
  		Bar.prototype[ syms[ 2 ] ] = 'c';
  		defineProperty( Bar.prototype, syms[ 3 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'd'
  		});
  	}
  
  	function Foo() {
  		Bar.call( this );
  		this.beep = 'boop';
  		this.a = {
  			'b': 'c'
  		};
  		defineProperty( this, 'd', {
  			'configurable': false,
  			'enumerable': false,
  			'writable': true,
  			'value': 'e'
  		});
  		if ( hasSymbols ) {
  			defineProperty( this, syms[ 1 ], {
  				'configurable': false,
  				'enumerable': false,
  				'writable': true,
  				'value': 'b'
  			});
  		}
  		return this;
  	}
  
  	inherit( Foo, Bar );
  
  	Foo.prototype.foo = [ 'bar' ];
  	defineProperty( Foo.prototype, 'baz', {
  		'configurable': false,
  		'enumerable': false,
  		'writable': false,
  		'value': 'bap'
  	});
  	if ( hasSymbols ) {
  		Foo.prototype[ syms[ 2 ] ] = 'c';
  		defineProperty( Foo.prototype, syms[ 4 ], {
  			'configurable': false,
  			'enumerable': false,
  			'writable': false,
  			'value': 'e'
  		});
  	}
  
  	obj = new Foo();
  
  	expected = [ 'foo' ];
  	if ( hasSymbols ) {
  		expected.push( syms[ 2 ] );
  	}
  	actual = inheritedWritableProperties( obj, 1 );
  
  	t.strictEqual( actual.length >= expected.length, true, '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() );
  	}
  	idx = indexOf( actual, 'bar' );
  	t.strictEqual( idx === -1, true, 'does not contain property' );
  	if ( hasSymbols ) {
  		idx = indexOf( actual, syms[ 3 ] );
  		t.strictEqual( idx === -1, true, 'does not contain property' );
  	}
  	t.end();
  });
  
  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 = inheritedWritableProperties( values[ i ] );
  		t.deepEqual( actual, expected, 'returns expected value when provided '+values[ i ] );
  	}
  	t.end();
  });
  