68 lines
1.7 KiB
JavaScript
68 lines
1.7 KiB
JavaScript
/**
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* @license Apache-2.0
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*
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* Copyright (c) 2018 The Stdlib Authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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// MODULES //
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var isUint8Array = require( '@stdlib/assert-is-uint8array' );
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var UINT8_MAX = require( '@stdlib/constants-uint8-max' );
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var GlobalUint8Array = require( './uint8array.js' );
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// MAIN //
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/**
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* Tests for native `Uint8Array` support.
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*
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* @returns {boolean} boolean indicating if an environment has `Uint8Array` support
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*
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* @example
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* var bool = hasUint8ArraySupport();
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* // returns <boolean>
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*/
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function hasUint8ArraySupport() {
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var bool;
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var arr;
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if ( typeof GlobalUint8Array !== 'function' ) {
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return false;
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}
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// Test basic support...
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try {
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arr = [ 1, 3.14, -3.14, UINT8_MAX+1, UINT8_MAX+2 ];
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arr = new GlobalUint8Array( arr );
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bool = (
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isUint8Array( arr ) &&
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arr[ 0 ] === 1 &&
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arr[ 1 ] === 3 && // truncation
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arr[ 2 ] === UINT8_MAX-2 && // truncation and wrap around
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arr[ 3 ] === 0 && // wrap around
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arr[ 4 ] === 1 // wrap around
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);
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} catch ( err ) { // eslint-disable-line no-unused-vars
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bool = false;
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}
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return bool;
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}
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// EXPORTS //
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module.exports = hasUint8ArraySupport;
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