$test-memoize-1: 0 !global;
$test-memoize-2: 0 !global;
@function test-memoize-1($a, $b) {
    $test-memoize-1: $test-memoize-1 + 1 !global;
    @return $a + $b;
}
@function test-memoize-2($a) {
    $test-memoize-2: $test-memoize-2 + 1 !global;
    @return $a + 3;
}
@include test-module('_memoize and _memo') {
    @include test('should memoize results based on first argument provided') {
        $memoized: _memoize(test-add);

        @include assert-equal(_exec($memoized, 1, 2), 3);
        @include assert-equal(_exec($memoized, 1, 5), 3);
        @include assert-equal(_exec($memoized, 2, 5), 7);
    }

    @include test('should properly memoize by only executing the idempotent function once given the same arguments') {
        $memoized: _memoize(test-memoize-1);
        
        @include assert-equal(_exec($memoized, 1, 2), 3);
        @include assert-equal($test-memoize-1, 1);

        @include assert-equal(_exec($memoized, 1, 2), 3);
        @include assert-equal($test-memoize-1, 1);
    }

    @include test('should support a resolver argument') {
        $memoized: _memoize(test-add, test-square);

        @include assert-equal(_exec($memoized, 3, 2), 5);
        @include assert-equal(_exec($memoized, -3, 2), 5);
    }

    @include test('should allow $__memoize__ cache to be set via _memo') {
        $memoized: _memoize(test-double);

        @include assert-equal(_exec($memoized, 5), 10);

        $_: _memo(test-double, 5, 55);

        @include assert-equal(_exec($memoized, 5), 55);
    }

    @include test('should support retrieving a cached value via _memo') {
        $test-memoize-1: 0 !global;

        $memoized: _memoize(test-memoize-2);

        $result: _exec($memoized, 7);

        $actual: _memo(test-memoize-2, 7);

        @include assert-equal($actual, $result);
        @include assert-equal($test-memoize-2, 1);
    }

    @include test('_memo should return null for non-cached values') {
        @include assert-equal(_memo(test-add, 99999), null);
    }
}