/** * @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 hasSymbols = require( '@stdlib/assert-has-symbol-support' ); var hasToStringTag = require( '@stdlib/assert-has-tostringtag-support' ); var isString = require( './../lib/object.js' ); // VARIABLES // var opts = { 'skip': !hasSymbols() }; // TESTS // tape( 'main export is a function', function test( t ) { t.ok( true, __filename ); t.strictEqual( typeof isString, 'function', 'main export is a function' ); t.end(); }); tape( 'the function returns `true` if provided a string object', function test( t ) { t.strictEqual( isString( new String( 'a' ) ), true, 'returns expected value' ); // eslint-disable-line no-new-wrappers t.end(); }); tape( 'the function returns `false` if provided a primitive string', function test( t ) { t.strictEqual( isString( 'a' ), false, 'returns expected value' ); t.end(); }); tape( 'if `Symbol.toStringTag` is supported, the function guards against objects masquerading as `String` objects', opts, function test( t ) { var isString; var mock; isString = proxyquire( './../lib/object.js', { '@stdlib/assert-has-tostringtag-support': detect }); mock = { 'toString': toString, 'valueOf': valueOf }; if ( hasToStringTag() ) { mock[ Symbol.toStringTag ] = 'String'; } t.strictEqual( isString( mock ), false, 'returns expected value' ); t.end(); function detect() { return true; } function toString() { return 'a'; } function valueOf() { return 'a'; } }); tape( 'if `Symbol.toStringTag` is not supported, the function attempts to determine the native class', function test( t ) { var isString = proxyquire( './../lib/object.js', { '@stdlib/assert-has-tostringtag-support': detect }); t.strictEqual( isString( new String( 'a' ) ), true, 'returns expected value' ); // eslint-disable-line no-new-wrappers t.strictEqual( isString( {} ), false, 'returns expected value' ); t.end(); function detect() { return false; } }); tape( 'the function returns `false` if not provided a string', function test( t ) { var values; var i; values = [ 5, NaN, null, true, void 0, [], {}, new Date(), /./, new RegExp( '.' ), // eslint-disable-line prefer-regex-literals function noop() {} ]; for ( i = 0; i < values.length; i++ ) { t.strictEqual( isString( values[i] ), false, 'returns false when provided '+values[i] ); } t.end(); });