test.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 tape = require( 'tape' );
var Int8Array = require( '@stdlib/array/int8' );
var Uint8Array = require( '@stdlib/array/uint8' );
var Uint8ClampedArray = require( '@stdlib/array/uint8c' );
var Int16Array = require( '@stdlib/array/int16' );
var Uint16Array = require( '@stdlib/array/uint16' );
var Int32Array = require( '@stdlib/array/int32' );
var Uint32Array = require( '@stdlib/array/uint32' );
var Float32Array = require( '@stdlib/array/float32' );
var Float64Array = require( '@stdlib/array/float64' );
var array2buffer = require( '@stdlib/buffer/from-array' );
var isUnityProbabilityArray = require( './../lib' );


// TESTS //

tape( 'main export is a function', function test( t ) {
	t.ok( true, __filename );
	t.equal( typeof isUnityProbabilityArray, 'function', 'main export is a function' );
	t.end();
});

tape( 'the function returns `true` if provided an array of probabilities that sum to one', function test( t ) {
	var values;
	var i;

	values = [
		new Int8Array( [ 0, 0, 1 ] ),
		new Uint8Array( [ 1, 0, 0 ] ),
		new Uint8ClampedArray( [ 0, 1 ] ),
		new Int16Array( [ 0, 0, 1, 0 ] ),
		new Uint16Array( [ 1 ] ),
		new Int32Array( [ 1, 0, 0 ] ),
		new Uint32Array( [ 0, 1, 0 ] ),
		new Float32Array( [ 0.0, 0.5, 0.5 ] ),
		new Float64Array( [ 0.25, 0.25, 0.5 ] ),
		[ 0.5, 0.25, 0.25 ]
	];

	for ( i = 0; i < values.length; i++ ) {
		t.strictEqual( isUnityProbabilityArray( values[i] ), true, 'returns true when provided '+values[i] );
	}
	t.end();
});

tape( 'the function allows a difference in sum within floating-point epsilon', function test( t ) {
	var bool = isUnityProbabilityArray( [ 0.1, 0.2, 0.1, 0.1, 0.2, 0.2, 0.1 ] );
	t.strictEqual( bool, true, 'returns true' );
	t.end();
});

tape( 'the function returns `false` if not provided an array of probabilities that sum to one', function test( t ) {
	var values;
	var i;

	values = [
		'10',
		'01',
		'0.5',
		'5',
		5,
		NaN,
		null,
		void 0,
		true,
		[],
		[ 5, null ],
		[ 5, '5' ],
		[ 1.0, 3.14 ],
		[ -1.0, 1.0, 1.0 ],
		[ 0.25, 0.33, 0.5 ],
		new Float64Array( [ 0.25, 0.33, 0.5 ] ),
		new Float64Array( [ 0.25, 1.33, 0.5 ] ),
		new Float64Array( [ 0.25, -0.33, 0.5 ] ),
		{},
		function noop() {},
		array2buffer( [ 1, 1, 0 ] )
	];

	for ( i = 0; i < values.length; i++ ) {
		t.strictEqual( isUnityProbabilityArray( values[i] ), false, 'returns false when provided '+values[i] );
	}
	t.end();
});