main.js

/**
* @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 isInt8Array = require( '@stdlib/assert-is-int8array' );
var INT8_MAX = require( '@stdlib/constants-int8-max' );
var INT8_MIN = require( '@stdlib/constants-int8-min' );
var GlobalInt8Array = require( './int8array.js' );


// MAIN //

/**
* Tests for native `Int8Array` support.
*
* @returns {boolean} boolean indicating if an environment has `Int8Array` support
*
* @example
* var bool = hasInt8ArraySupport();
* // returns <boolean>
*/
function hasInt8ArraySupport() {
	var bool;
	var arr;

	if ( typeof GlobalInt8Array !== 'function' ) {
		return false;
	}
	// Test basic support...
	try {
		arr = new GlobalInt8Array( [ 1, 3.14, -3.14, INT8_MAX+1 ] );
		bool = (
			isInt8Array( arr ) &&
			arr[ 0 ] === 1 &&
			arr[ 1 ] === 3 &&     // truncation
			arr[ 2 ] === -3 &&    // truncation
			arr[ 3 ] === INT8_MIN // wrap around
		);
	} catch ( err ) { // eslint-disable-line no-unused-vars
		bool = false;
	}
	return bool;
}


// EXPORTS //

module.exports = hasInt8ArraySupport;