text: /**
  * @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 isnan = require( '@stdlib/math/base/assert/is-nan' );
  var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
  var PINF = require( '@stdlib/constants/math/float64-pinf' );
  var NINF = require( '@stdlib/constants/math/float64-ninf' );
  var FLOAT64_MAX = require( '@stdlib/constants/math/float64-max' );
  var pdiff = require( './../lib' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.strictEqual( typeof pdiff, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function returns `NaN` if provided a `NaN`', function test( t ) {
  	var v;
  
  	v = pdiff( NaN, 3.14 );
  	t.strictEqual( isnan( v ), true, 'returns NaN' );
  
  	v = pdiff( 3.14, NaN );
  	t.strictEqual( isnan( v ), true, 'returns NaN' );
  
  	v = pdiff( NaN, NaN );
  	t.strictEqual( isnan( v ), true, 'returns NaN' );
  
  	t.end();
  });
  
  tape( 'the function returns `+infinity` if the first argument is `+infinity`', function test( t ) {
  	var v;
  
  	v = pdiff( PINF, 3.14 );
  	t.strictEqual( v, PINF, 'returns +infinity' );
  
  	v = pdiff( PINF, NINF );
  	t.strictEqual( v, PINF, 'returns +infinity' );
  
  	t.end();
  });
  
  tape( 'the function returns `0` if both arguments are `+infinity`', function test( t ) {
  	var v = pdiff( PINF, PINF );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  	t.end();
  });
  
  tape( 'the function returns positive zero if the difference between the first and second arguments is less than or equal to `0`', function test( t ) {
  	var v;
  
  	v = pdiff( +0.0, -0.0 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	v = pdiff( -0.0, +0.0 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	v = pdiff( -0.0, -0.0 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	v = pdiff( +0.0, +0.0 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	v = pdiff( 3.14, 3.14 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	v = pdiff( 3.14, 4.2 );
  	t.strictEqual( isPositiveZero( v ), true, 'returns +0' );
  
  	t.end();
  });
  
  tape( 'the function returns the positive difference between `x` and `y`', function test( t ) {
  	var v;
  
  	v = pdiff( 4.2, 3.14 );
  	t.strictEqual( v, 1.06, 'returns the positive difference' );
  
  	v = pdiff( -4.2, 3.14 );
  	t.strictEqual( v, 0.0, 'returns the positive difference' );
  
  	v = pdiff( -4.2, -5.2 );
  	t.strictEqual( v, 1.0, 'returns the positive difference' );
  
  	t.end();
  });
  
  tape( 'the function returns `+infinity` if overflow occurs', function test( t ) {
  	var half;
  	var v;
  
  	half = FLOAT64_MAX / 2.0;
  	v = pdiff( half, -(half*1.5) );
  	t.strictEqual( v, PINF, 'returns +infinity' );
  
  	t.end();
  });
  