@include test-module('_is-equal') {
    @include test('should perform comparisons between primitive values') {    
        $pairs: (
            (1, 1, true), (1, '1', false), (1, 2, false),
            (0, 0, true), (0, '0', false), (0, null, false),
            ('a', 'a', true), ('a', a, true), (a, a, true), ('a', 'b', false), ('a', ('a',), false),
            (true, true, true), (true, 1, false), (true, 'a', false),
            (false, false, true), (false, 0, false), (false, '', false),
            (null, null, true), (null, (), false), (null, '', false)
        );

        @each $pair in $pairs {
            @include assert-equal(_is-equal(nth($pair, 1), nth($pair, 2)), nth($pair, 3),
                'values #{inspect(nth($pair, 1))} == #{inspect(nth($pair, 2))} should equal #{nth($pair, 3)}');
        }
    }

    @include test('should perform comparisons between lists') {
        $list1: true null 1 'a' ('b': 2) #112233;
        $list2: true null 1 'a' ('b': 2) #112233;

        @include assert-equal(_is-equal($list1, $list2), true);

        @include assert-equal(_is-equal(1 2 3, 3 2 1), false);
    }

    @include test('should perform comparisons between plain maps') {
        $map1: ('a': true, 'b': null, 'c': 1, 'd': 'a', 'e': false);
        $map2: ('a': true, 'b': null, 'c': 1, 'd': 'a', 'e': false);

        @include assert-equal(_is-equal($map1, $map2), true);

        $map1: ('a': 1, 'b': 2, 'c': 3);
        $map2: ('a': 3, 'b': 2, 'c': 1);

        @include assert-equal(_is-equal($map1, $map2), false);

        $map1: ('a': 1, 'b': 2, 'c': 3);
        $map2: ('d': 1, 'e': 2, 'f': 3);

        @include assert-equal(_is-equal($map1, $map2), false);

        $map1: ('a': 1, 'b': 2);
        $map2: ('a': 1, 'b': 2, 'c': 3);

        @include assert-equal(_is-equal($map1, $map2), false);

        $map1: ('a': 1, 'b': 2, 'c': 3);
        $map2: ('c': 3, 'b': 2, 'a': 1);

        @include assert-equal(_is-equal($map1, $map2), true);
    }

    @include test('should perform comparisons of nested maps') {
        $map1: (
            'a': 1 2 3,
            'b': true,
            'c': 1,
            'd': 'a',
            'e': (
                'f': 'a' 'b' 'c',
                'g': false,
                'h': _noop,
                'j': 'a'
            )
        );

        $map2: (
            'a': 1 2 3,
            'b': not false,
            'c': 3 - 2,
            'd': a,
            'e': (
                'f': 'a' 'b' 'c',
                'g': 1 == 2,
                'h': '_noop',
                'j': 'a'
            )
        );

        @include assert-equal(_is-equal($map1, $map2), true);
    }

    @include test('should handle comparisons if customizer returns null') {
        @include assert-equal(_is-equal('a', 'a', _noop), true);
    }

    @include test('should return a boolean value even if customizer does not') {
        @include assert-equal(_is-equal('a', 'a', _constant('a')), true);
    }

    @include test('should work as an iteratee for _every') {
        @include assert-equal(_every(1 1 1, _partial(_is-equal, 1)), true);
    }

    @include test('should be chainable') {
        $actual: _('a', _is-equal 'a');

        @include assert-equal($actual, true);
    }
}