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 noop = require( '@stdlib/utils/noop' );
  var inmapAsync = require( './../lib/inmap.js' );
  
  
  // TESTS //
  
  tape( 'main export is a function', function test( t ) {
  	t.ok( true, __filename );
  	t.strictEqual( typeof inmapAsync, 'function', 'main export is a function' );
  	t.end();
  });
  
  tape( 'the function throws an error if not provided a collection', function test( t ) {
  	var values;
  	var i;
  
  	function next( value, clbk ) {
  		clbk( null, value );
  	}
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		function noop() {},
  		/.*/,
  		new Date()
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( value, next, noop );
  		};
  	}
  });
  
  tape( 'the function throws an error if not provided a function to invoke for each collection element (no options)', function test( t ) {
  	var values;
  	var i;
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[]
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( [ 1, 2, 3 ], value, noop );
  		};
  	}
  });
  
  tape( 'the function throws an error if not provided a function to invoke for each collection element (options)', function test( t ) {
  	var values;
  	var i;
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[]
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( [ 1, 2, 3 ], {}, value, noop );
  		};
  	}
  });
  
  tape( 'the function throws an error if not provided a callback function (no options)', function test( t ) {
  	var values;
  	var i;
  
  	function next( value, clbk ) {
  		clbk( null, value );
  	}
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[]
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( [ 1, 2, 3 ], next, value );
  		};
  	}
  });
  
  tape( 'the function throws an error if not provided a callback function (options)', function test( t ) {
  	var values;
  	var i;
  
  	function next( value, clbk ) {
  		clbk( null, value );
  	}
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		{},
  		[]
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( [ 1, 2, 3 ], {}, next, value );
  		};
  	}
  });
  
  tape( 'the function throws an error if provided an `options` argument which is not an object', function test( t ) {
  	var values;
  	var i;
  
  	function next( value, clbk ) {
  		clbk( null, value );
  	}
  
  	values = [
  		'5',
  		5,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		[],
  		function noop() {}
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			inmapAsync( [ 1, 2, 3 ], value, next, noop );
  		};
  	}
  });
  
  tape( 'the function throws an error if provided an invalid option', function test( t ) {
  	var values;
  	var i;
  
  	function next( value, clbk ) {
  		clbk( null, value );
  	}
  
  	values = [
  		'5',
  		-5,
  		3.14,
  		0,
  		NaN,
  		true,
  		false,
  		null,
  		void 0,
  		[],
  		{},
  		function noop() {}
  	];
  
  	for ( i = 0; i < values.length; i++ ) {
  		t.throws( badValue( values[i] ), TypeError, 'throws a type error when provided '+values[i] );
  	}
  	t.end();
  
  	function badValue( value ) {
  		return function badValue() {
  			var opts = {
  				'limit': value
  			};
  			inmapAsync( [ 1, 2, 3 ], opts, next, noop );
  		};
  	}
  });
  
  tape( 'the function invokes a provided function once for each element in a collection and updates a collection in-place (value,next)', function test( t ) {
  	var expected1;
  	var expected2;
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	expected1 = [ 1, 2, 3 ];
  	expected2 = [ 2, 4, 6 ];
  	i = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, next ) {
  		i += 1;
  		t.strictEqual( value, expected1[ i ], 'provides expected value' );
  
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			next( null, value*2 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function invokes a provided function once for each element in a collection and updates a collection in-place (value,index,next)', function test( t ) {
  	var expected1;
  	var expected2;
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	expected1 = [ 1, 2, 3 ];
  	expected2 = [ 3, 6, 9 ];
  	i = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, next ) {
  		i += 1;
  		t.strictEqual( value, expected1[ index ], 'provides expected value' );
  		t.strictEqual( index, i, 'provides expected index' );
  
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			next( null, value*3 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function invokes a provided function once for each element in a collection and updates a collection in-place (value,index,collection,next)', function test( t ) {
  	var expected1;
  	var expected2;
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	expected1 = [ 1, 2, 3 ];
  	expected2 = [ 'beep0', 'beep1', 'beep2' ];
  	i = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, collection, next ) {
  		i += 1;
  		t.strictEqual( value, expected1[ index ], 'provides expected value' );
  		t.strictEqual( index, i, 'provides expected index' );
  		t.strictEqual( collection, arr, 'provides input collection' );
  
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			next( null, 'beep'+index );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'if a provided function accepts fewer than 2 arguments, the function invokes a provided function with four arguments (1 argument)', function test( t ) {
  	var expected1;
  	var expected2;
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	expected1 = [ 1, 2, 3 ];
  	expected2 = [ 2, 4, 6 ];
  	i = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value ) {
  		var next = arguments[ 3 ];
  		i += 1;
  
  		t.strictEqual( value, expected1[ i ], 'provides expected value' );
  		t.strictEqual( arguments[ 1 ], i, 'provides expected index' );
  		t.strictEqual( arguments[ 2 ], arr, 'provides input collection' );
  
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			next( null, value*2 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'if a provided function length is 0, the function invokes a provided function with four arguments', function test( t ) {
  	var expected1;
  	var expected2;
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	expected1 = [ 1, 2, 3 ];
  	expected2 = [ 3, 6, 9 ];
  	i = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn() {
  		var next;
  		var v;
  
  		next = arguments[ 3 ];
  		v = arguments[ 0 ];
  
  		i += 1;
  
  		t.strictEqual( v, expected1[ i ], 'provides expected value' );
  		t.strictEqual( arguments[ 1 ], i, 'provides expected index' );
  		t.strictEqual( arguments[ 2 ], arr, 'provides input collection' );
  
  		setTimeout( onTimeout, arguments[ 0 ] );
  
  		function onTimeout() {
  			next( null, v*3 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'by default, the function processes collection elements concurrently', function test( t ) {
  	var expected1;
  	var expected2;
  	var count;
  	var arr;
  
  	arr = [ 300, 250, 100 ];
  	expected1 = [ 100, 250, 300 ];
  	expected2 = [ 3.0, 2.5, 1.0 ];
  	count = -1;
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			count += 1;
  			t.strictEqual( value, expected1[ count ], 'provides expected value' );
  			next( null, value/100.0 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function supports processing collection elements sequentially (in series)', function test( t ) {
  	var expected1;
  	var expected2;
  	var count;
  	var opts;
  	var arr;
  
  	arr = [ 300, 250, 100 ];
  	expected1 = [ 300, 250, 100 ];
  	expected2 = [ 3.0, 2.5, 1.0 ];
  	count = -1;
  
  	opts = {
  		'series': true
  	};
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			count += 1;
  			t.strictEqual( value, expected1[ count ], 'provides expected value' );
  			next( null, value/100.0 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function supports processing collection elements sequentially (limit = 1)', function test( t ) {
  	var expected1;
  	var expected2;
  	var count;
  	var opts;
  	var arr;
  
  	arr = [ 300, 250, 100 ];
  	expected1 = [ 300, 250, 100 ];
  	expected2 = [ 3.0, 2.5, 1.0 ];
  	count = -1;
  
  	opts = {
  		'series': false,
  		'limit': 1
  	};
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			count += 1;
  			t.strictEqual( value, expected1[ count ], 'provides expected value' );
  			next( null, value/100.0 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function supports limiting the maximum number of collection elements which are processed at any one time', function test( t ) {
  	var expected1;
  	var expected2;
  	var count;
  	var opts;
  	var arr;
  
  	arr = [ 300, 250, 100 ];
  	expected1 = [ 250, 300, 100 ];
  	expected2 = [ 3.0, 2.5, 1.0 ];
  	count = -1;
  
  	opts = {
  		'series': false,
  		'limit': 2
  	};
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			count += 1;
  			t.strictEqual( value, expected1[ count ], 'provides expected value' );
  			next( null, value/100.0 );
  		}
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, expected2, 'updates all values' );
  		t.end();
  	}
  });
  
  tape( 'the function supports specifying an execution context for the invoked function', function test( t ) {
  	var opts;
  	var arr;
  	var ctx;
  
  	arr = [ 1, 2, 3 ];
  	ctx = {
  		'count': 0
  	};
  	opts = {
  		'thisArg': ctx
  	};
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		/* eslint-disable no-invalid-this */
  		this.count += 1;
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			next( null, value );
  		}
  	}
  
  	function done( error ) {
  		t.strictEqual( ctx.count, 3, 'updated provided context' );
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered while processing a collection element, the function suspends execution and immediately returns the error (series)', function test( t ) {
  	var count;
  	var opts;
  	var arr;
  
  	arr = [ 1, 2, 3 ];
  	opts = {
  		'series': true
  	};
  	count = 0;
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			count += 1;
  			next( new Error( 'beep' ) );
  		}
  	}
  
  	function done( error ) {
  		t.strictEqual( count, 1, 'suspends execution' );
  		if ( error ) {
  			t.pass( error.message );
  		} else {
  			t.fail( 'did not return an error' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered while processing a collection element, the function suspends execution and immediately returns the error (concurrent; limit)', function test( t ) {
  	var count;
  	var opts;
  	var arr;
  
  	arr = [ 300, 100, 250 ];
  	opts = {
  		'limit': 2
  	};
  	count = 0;
  	inmapAsync( arr, opts, fcn, done );
  
  	function fcn( value, index, next ) {
  		count += 1;
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			if ( index === 1 ) {
  				return next( new Error( 'beep' ) );
  			}
  			next( null, value );
  		}
  	}
  
  	function done( error ) {
  		t.strictEqual( count, 2, 'suspends execution' );
  		if ( error ) {
  			t.pass( error.message );
  		} else {
  			t.fail( 'did not return an error' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered while processing a collection element, the function suspends execution and immediately returns the error (concurrent)', function test( t ) {
  	var count;
  	var arr;
  
  	arr = [ 500, 500, 500 ];
  	count = 0;
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, next ) {
  		count += 1;
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			if ( index === 1 ) {
  				return next( new Error( 'beep' ) );
  			}
  			next( null, value );
  		}
  	}
  
  	function done( error ) {
  		t.strictEqual( count, 3, 'suspends execution' );
  		if ( error ) {
  			t.pass( error.message );
  		} else {
  			t.fail( 'did not return an error' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered while processing a collection element, the function suspends execution and immediately returns the error (concurrent)', function test( t ) {
  	var count;
  	var arr;
  
  	arr = [ 500, 500, 500 ];
  	count = 0;
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, next ) {
  		count += 1;
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			return next( new Error( 'beep' ) );
  		}
  	}
  
  	function done( error ) {
  		t.strictEqual( count, 3, 'suspends execution' );
  		if ( error ) {
  			t.pass( error.message );
  		} else {
  			t.fail( 'did not return an error' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered while processing a collection element, a collection may be partially mutated', function test( t ) {
  	var expected;
  	var arr;
  
  	arr = [ 100, 200, 300 ];
  	expected = [ 1.0, 200, 300 ];
  
  	inmapAsync( arr, fcn, done );
  
  	function fcn( value, index, next ) {
  		setTimeout( onTimeout, value );
  
  		function onTimeout() {
  			if ( index === 1 ) {
  				return next( new Error( 'beep' ) );
  			}
  			next( null, value/100.0 );
  		}
  	}
  
  	function done( error ) {
  		if ( error ) {
  			t.pass( error.message );
  		} else {
  			t.fail( 'did not return an error' );
  		}
  		t.deepEqual( arr, expected, 'partially mutates a collection' );
  		t.end();
  	}
  });
  
  tape( 'if provided an empty collection, the function never invokes a provided function', function test( t ) {
  	var arr = [];
  	inmapAsync( arr, fcn, done );
  
  	function fcn() {
  		t.fail( 'should never be called' );
  	}
  
  	function done( error, collection ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( collection, arr, 'returns input collection' );
  		t.deepEqual( collection, [], 'returns an empty collection' );
  		t.end();
  	}
  });
  
  tape( 'the function does not guarantee asynchronous execution', function test( t ) {
  	var arr;
  	var i;
  
  	arr = [ 1, 2, 3 ];
  	i = 0;
  	inmapAsync( arr, fcn, done );
  	i = 1;
  
  	function fcn( value, next ) {
  		next( null, value );
  	}
  
  	function done( error ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.pass( 'did not return an error' );
  		}
  		t.strictEqual( i, 0, 'releases the zalgo' );
  		t.end();
  	}
  });
  