@stdlib/array/base/first/docs/types/test.ts

Arrays.

/*
* @license Apache-2.0
*
* Copyright (c) 2023 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.
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import first = require( './index' );


// TESTS //

// The function returns an array element...
{
	first( [ 1, 2, 3 ] ); // $ExpectType number
}

// The compiler throws an error if the function is provided an argument which is not a collection...
{
	first( 5 ); // $ExpectError
	first( true ); // $ExpectError
	first( false ); // $ExpectError
	first( null ); // $ExpectError
	first( {} ); // $ExpectError
}

// The compiler throws an error if the function is provided an unsupported number of arguments...
{
	first(); // $ExpectError
	first( [ 1, 2, 3 ], 2 ); // $ExpectError
}