functional-php/tests/Collections/QueriesTest.php

<?php
/**
 * Copyright 2026 Kacper Donat
 *
 * @author Kacper "Kadet" Donat <kacper@kadet.net>
 *
 * Full license available in separate LICENSE file
 */

use Ds\Map;
use Ds\Seq;
use Kadet\Functional\Collections as c;
use Kadet\Functional\Exception\EmptyCollectionException;

class QueriesTest extends \PHPUnit\Framework\TestCase
{
    public function testFirstReturnsNullOnEmpty()
    {
        $this->assertNull(c\first()([]));
        $this->assertNull(c\first(fn ($v) => $v > 5)([1, 2]));
    }

    public function testFirstRequiredThrowsWithMessage()
    {
        $this->expectException(EmptyCollectionException::class);
        $this->expectExceptionMessage('first(): no element matched');
        c\first(fn ($v) => $v > 5, required: true)([1, 2]);
    }

    public function testFirstRequiredWithoutPredicateSaysEmpty()
    {
        $this->expectException(EmptyCollectionException::class);
        $this->expectExceptionMessage('first(): collection is empty');
        c\first(required: true)([]);
    }

    public function testFirstRequiredAcceptsNullMatch()
    {
        $this->assertNull(c\first(fn ($v) => $v === null, required: true)([1, null]));
    }

    public function testFirstFalsyValueFound()
    {
        $this->assertSame(0, c\first()([0]));
    }

    public function testFirstStopsEarly()
    {
        $gen = (static function () {
            yield 1;
            throw new \LogicException('consumed too far');
        })();

        $this->assertSame(1, c\first()($gen));
    }

    public function testFirstPassesKeyToPredicate()
    {
        $this->assertSame(2, c\first(fn ($v, $k) => $k === 'b')(['a' => 1, 'b' => 2]));
        $this->assertSame(2, c\first(fn ($v, $k) => $k === 'b')(new Map(['a' => 1, 'b' => 2])));
    }

    public function testFindIsFirstWithPredicate()
    {
        $this->assertSame(2, c\find(fn ($v) => $v > 1)([1, 2, 3]));

        $this->expectException(EmptyCollectionException::class);
        $this->expectExceptionMessage('find(): no element matched');
        c\find(fn ($v) => $v > 5, required: true)([1, 2, 3]);
    }

    public function testLastOnArrayAndPredicate()
    {
        $this->assertSame(3, c\last()([1, 2, 3]));
        $this->assertSame(2, c\last(fn ($v) => $v < 3)([1, 2, 3]));
        $this->assertNull(c\last()([]));
    }

    public function testLastOnGenerator()
    {
        $gen = (static function () {
            yield 'a' => 1;
            yield 'b' => 2;
        })();

        $this->assertSame(2, c\last()($gen));
    }

    public function testLastOnSeqAndSet()
    {
        $this->assertSame(3, c\last()(new Seq([1, 2, 3])));
        $this->assertSame(2, c\last(fn ($v, $k) => $k < 2)(new Seq([1, 2, 3])));
        $this->assertSame(3, c\last()(new \Ds\Set([1, 2, 3])));
        $this->assertNull(c\last()(new Seq()));
    }

    public function testLastOnMapReturnsValue()
    {
        $this->assertSame('y', c\last()(new Map(['a' => 'x', 'b' => 'y'])));
        $this->assertSame('x', c\last(fn ($v, $k) => $k === 'a')(new Map(['a' => 'x', 'b' => 'y'])));
    }

    public function testLastRequired()
    {
        $this->assertNull(c\last(fn ($v) => $v === null, required: true)([null, 1]));

        $this->expectException(EmptyCollectionException::class);
        $this->expectExceptionMessage('last(): collection is empty');
        c\last(required: true)([]);
    }

    public function testLastRequiredNoMatchMessage()
    {
        $this->expectException(EmptyCollectionException::class);
        $this->expectExceptionMessage('last(): no element matched');
        c\last(fn ($v) => false, required: true)([1]);
    }

    public function testContainsIsStrict()
    {
        $this->assertFalse(c\contains('1')([1]));
        $this->assertTrue(c\contains(1)([3, 1]));
        $this->assertTrue(c\contains(null)([1, null]));
    }

    public function testContainsUsesDsKey()
    {
        $key = new class (1) implements \Ds\Key {
            public function __construct(public int $id) {}

            public function equals(mixed $obj): bool
            {
                return $obj->id === $this->id;
            }

            public function hash(): mixed
            {
                return $this->id;
            }
        };

        $this->assertTrue(c\contains($key)([new $key(1)]));
        $this->assertFalse(c\contains($key)([new $key(2)]));
    }

    public function testAnySomeEvery()
    {
        $this->assertTrue(c\any(fn ($v) => $v > 2)([1, 3]));
        $this->assertFalse(c\any(fn ($v) => $v > 5)([1, 3]));
        $this->assertFalse(c\any(fn ($v) => true)([]));
        $this->assertTrue(c\some(fn ($v) => $v > 2)([1, 3]));
        $this->assertTrue(c\every(fn ($v) => $v > 0)([1, 3]));
        $this->assertFalse(c\every(fn ($v) => $v > 1)([1, 3]));
    }

    public function testEveryOnEmptyIsTrue()
    {
        $this->assertTrue(c\every(fn ($v) => false)([]));
    }

    public function testAnyStopsEarly()
    {
        $gen = (static function () {
            yield 1;
            throw new \LogicException('consumed too far');
        })();

        $this->assertTrue(c\any(fn ($v) => $v === 1)($gen));
    }

    public function testCountAndIsEmpty()
    {
        $gen = (static function () {
            yield 1;
            yield 2;
        })();

        $this->assertSame(2, c\count()($gen));
        $this->assertSame(3, c\count()(new Seq([1, 2, 3])));
        $this->assertSame(0, c\count()([]));
        $this->assertTrue(c\isEmpty()([]));
        $this->assertFalse(c\isEmpty()(new Seq([0])));
        $this->assertTrue(c\isEmpty()(new Map()));
    }

    public function testMinMax()
    {
        $this->assertSame(1, c\min()([3, 1, 2]));
        $this->assertSame(3, c\max()([3, 1, 2]));
        $this->assertNull(c\min()([]));
        $this->assertNull(c\max()([]));
    }

    public function testMinWithSelector()
    {
        $this->assertSame(1, c\min(fn ($v) => strlen($v))(['ccc', 'a', 'bb']));
        $this->assertSame(3, c\max(fn ($v) => strlen($v))(['ccc', 'a', 'bb']));
    }

    public function testReduce()
    {
        $this->assertSame(6, c\reduce(fn ($carry, $v) => $carry + $v, 0)([1, 2, 3]));
        $this->assertSame('a:1,b:2,', c\reduce(fn ($carry, $v, $k) => "$carry$k:$v,", '')(['a' => 1, 'b' => 2]));
        $this->assertNull(c\reduce(fn ($carry, $v) => $v)([]));
    }

    public function testSum()
    {
        $this->assertSame(6, c\sum()([1, 2, 3]));
        $this->assertSame(3.5, c\sum()([1, 2.5]));
        $this->assertSame(4, c\sum(fn ($v) => strlen($v))(['ab', 'cd']));
    }

    public function testSumEmptyIsZero()
    {
        $this->assertSame(0, c\sum()([]));
    }

    public function testJoin()
    {
        $this->assertSame('a, b', c\join(', ')(['a', 'b']));
        $this->assertSame('12', c\join()(new Seq([1, 2])));
        $this->assertSame('', c\join(',')([]));
    }
}