[Iter] add more tests (#41)

src/Psl/Gen/flatten.php

@@ -10,7 +10,7 @@ use Generator;
  * Returns a generator formed by merging the iterable elements of the
  * given iterable.
  *
- * @psalm-template Tk of array-key
+ * @psalm-template Tk
  * @psalm-template Tv
  *
  * @psalm-param iterable<iterable<Tk, Tv>> $iterables

src/Psl/Iter/first_key.php

@@ -22,17 +22,18 @@ use Psl\Arr;
  *      Iter\first_key([])
  *      => Null
  *
- * @psalm-template Tk of array-key
+ * @psalm-template Tk
  * @psalm-template Tv
  *
  * @psalm-param    iterable<Tk, Tv> $iterable
  *
  * @psalm-return   null|Tk
- *
- * @see            Arr\first_key()
  */
 function first_key(iterable $iterable)
 {
-    /** @psalm-var null|Tk */
-    return Arr\first_key(to_array_with_keys($iterable));
+    foreach ($iterable as $k => $_) {
+        return $k;
+    }
+
+    return null;
 }

src/Psl/Iter/flatten.php

@@ -10,7 +10,7 @@ use Psl\Gen;
  * Returns an iterator formed by merging the iterable elements of the
  * given iterable.
  *
- * @psalm-template Tk of array-key
+ * @psalm-template Tk
  * @psalm-template Tv
  *
  * @psalm-param    iterable<iterable<Tk, Tv>> $iterables

src/Psl/Iter/last.php

@@ -4,22 +4,22 @@ declare(strict_types=1);
 
 namespace Psl\Iter;
 
-use Psl\Arr;
-
 /**
  * Get the last value of an iterable, if the iterable is empty, returns null.
  *
  * @psalm-template Tk of array-key
  * @psalm-template Tv
  *
- * @psalm-param    array<Tk, Tv> $iterable
+ * @psalm-param    iterable<Tk, Tv> $iterable
  *
  * @psalm-return   null|Tv
- *
- * @see            Arr\last()
  */
 function last(iterable $iterable)
 {
-    /** @psalm-var null|Tv */
-    return Arr\last(to_array_with_keys($iterable));
+    $last = null;
+    foreach ($iterable as $v) {
+        $last = $v;
+    }
+
+    return $last;
 }

src/Psl/Iter/last_key.php

@@ -4,22 +4,22 @@ declare(strict_types=1);
 
 namespace Psl\Iter;
 
-use Psl\Arr;
-
 /**
  * Get the last key of an iterable, if the iterable is empty, null will be returned.
  *
- * @psalm-template Tk of array-key
+ * @psalm-template Tk
  * @psalm-template Tv
  *
- * @psalm-param    array<Tk, Tv> $iterable
+ * @psalm-param    iterable<Tk, Tv> $iterable
  *
  * @psalm-return   null|Tk
- *
- * @see            Arr\last_key()
  */
 function last_key(iterable $iterable)
 {
-    /** @psalm-var null|Tk */
-    return Arr\last_key(to_array_with_keys($iterable));
+    $last = null;
+    foreach ($iterable as $k => $_) {
+        $last = $k;
+    }
+
+    return $last;
 }

tests/Psl/Iter/FilterNullsTest.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
 use Psl\Iter;
 
 class FilterNullsTest extends TestCase
@@ -16,5 +17,18 @@ class FilterNullsTest extends TestCase
         self::assertCount(1, Iter\filter_nulls([null, false]));
         self::assertCount(1, Iter\filter_nulls([null, 'null']));
         self::assertCount(1, Iter\filter_nulls(['null']));
+        self::assertCount(1, Iter\filter_nulls(new Iter\Iterator(['null'])));
+        self::assertCount(0, Iter\filter_nulls(new Iter\Iterator([null])));
+        self::assertCount(0, Iter\filter_nulls(new Iter\Iterator([null, null])));
+        self::assertCount(3, Iter\filter_nulls(new Iter\Iterator([null, false, '', 0])));
+        self::assertCount(3, Iter\filter_nulls(new Collection\Vector([null, false, '', 0])));
+        self::assertCount(3, Iter\filter_nulls(new Collection\Map([null, false, '', 0])));
+        self::assertCount(3, Iter\filter_nulls((static function (): iterable {
+            yield null;
+            yield false;
+            yield '';
+            yield 0;
+            yield null;
+        })()));
     }
 }

tests/Psl/Iter/FilterTest.php

@@ -5,8 +5,48 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Iter;
 
 class FilterTest extends TestCase
 {
-    // TODO: add tests.
+    /**
+     * @dataProvider provideData
+     */
+    public function testFilter(array $expected, iterable $iterable, ?callable $predicate = null): void
+    {
+        $result = Iter\filter($iterable, $predicate);
+
+        self::assertSame($expected, Iter\to_array_with_keys($result));
+    }
+
+    public function provideData(): iterable
+    {
+        yield  [[], []];
+        yield  [['a', 'b'], ['a', 'b']];
+        yield  [[], ['a', 'b'], fn () => false];
+        yield  [['a', 'b'], ['a', 'b'], fn (string $_): bool => true];
+        yield  [['a'], ['a', 'b'], fn (string $v): bool => 'b' !== $v];
+
+        yield  [['a', 'b'], new Iter\Iterator(['a', 'b'])];
+        yield  [[], new Iter\Iterator(['a', 'b']), fn () => false];
+        yield  [['a', 'b'], new Iter\Iterator(['a', 'b']), fn (string $_): bool => true];
+        yield  [['a'], new Iter\Iterator(['a', 'b']), fn (string $v): bool => 'b' !== $v];
+
+        yield  [['a', 'b'], (static function () {
+            yield 'a';
+            yield 'b';
+        })()];
+        yield  [[], (static function () {
+            yield 'a';
+            yield 'b';
+        })(), fn () => false];
+        yield  [['a', 'b'], (static function () {
+            yield 'a';
+            yield 'b';
+        })(), fn (string $_): bool => true];
+        yield  [['a'], (static function () {
+            yield 'a';
+            yield 'b';
+        })(), fn (string $v): bool => 'b' !== $v];
+    }
 }

tests/Psl/Iter/FilterWithKeyTest.php

@@ -5,8 +5,46 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
+use Psl\Iter;
 
 class FilterWithKeyTest extends TestCase
 {
-    // TODO: add tests.
+    /**
+     * @dataProvider provideData
+     */
+    public function testFilterWithKey(array $expected, iterable $iterable, ?callable $predicate = null): void
+    {
+        $result = Iter\filter_with_key($iterable, $predicate);
+
+        self::assertSame($expected, Iter\to_array_with_keys($result));
+    }
+
+    public function provideData(): iterable
+    {
+        yield  [[], []];
+        yield  [['a', 'b'], ['a', 'b']];
+        yield  [[], ['a', 'b'], fn (int $_k, string $_v) => false];
+        yield  [['a', 'b'], ['a', 'b'], fn (int $_k, string $_v): bool => true];
+        yield  [['a'], ['a', 'b'], fn (int $k, string $v): bool => 'b' !== $v];
+        yield  [[], ['a', 'b'], fn (int $k, string $v): bool => 'b' !== $v && 0 !== $k];
+        yield  [['a'], ['a', 'b'], fn (int $k, string $v): bool => 'b' !== $v && 1 !== $k];
+        yield  [[], ['a', 'b'], fn (int $k, string $v): bool => 'a' !== $v && 1 !== $k];
+        yield  [[1 => 'b'], ['a', 'b'], fn (int $k, string $v): bool => 'a' !== $v && 0 !== $k];
+
+        yield  [[], new \SplFixedArray(0)];
+        yield  [['a', 'b'], new Collection\Vector(['a', 'b'])];
+        yield  [[], new Collection\Map(['a', 'b']), fn (int $_k, string $_v) => false];
+        yield  [['a', 'b'], new Iter\Iterator(['a', 'b']), fn (int $_k, string $_v): bool => true];
+        yield  [['a'], new Collection\MutableMap(['a', 'b']), fn (int $k, string $v): bool => 'b' !== $v];
+        yield  [[], new Collection\MutableVector(['a', 'b']), fn (int $k, string $v): bool => 'b' !== $v && 0 !== $k];
+        yield  [['a'], new Iter\Iterator(['a', 'b']), fn (int $k, string $v): bool => 'b' !== $v && 1 !== $k];
+        yield  [[], new \ArrayIterator(['a', 'b']), fn (int $k, string $v): bool => 'a' !== $v && 1 !== $k];
+        yield  [[1 => 'b'], new \ArrayObject(['a', 'b']), fn (int $k, string $v): bool => 'a' !== $v && 0 !== $k];
+
+        $doublyLinkedList = new \SplDoublyLinkedList();
+        $doublyLinkedList->add(0, 'a');
+        $doublyLinkedList->add(1, 'b');
+        yield  [['a', 'b'], $doublyLinkedList];
+    }
 }

tests/Psl/Iter/FirstKeyTest.php

@@ -5,8 +5,36 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
+use Psl\Iter;
 
 class FirstKeyTest extends TestCase
 {
-    // TODO: add tests.
+    /**
+     * @dataProvider provideData
+     */
+    public function testFirstKey($expected, iterable $iterable): void
+    {
+        $result = Iter\first_key($iterable);
+
+        self::assertSame($expected, $result);
+    }
+
+    public function provideData(): iterable
+    {
+        yield [null, []];
+        yield [null, new \SplDoublyLinkedList()];
+        yield ['a', ['a' => 'b']];
+        yield [0, ['a', 'b']];
+        yield [0, new Collection\Vector(['a', 'b'])];
+        yield [0, new Collection\Vector(['a' => 'b'])];
+        yield ['a', new Collection\Map(['a' => 'b'])];
+        yield [null, (static function () {
+            yield null => null;
+        })()];
+        yield [null, (static function () {
+            return;
+            yield;
+        })()];
+    }
 }

tests/Psl/Iter/FirstTest.php

@@ -5,8 +5,36 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
+use Psl\Iter;
 
 class FirstTest extends TestCase
 {
-    // TODO: add tests.
+    /**
+     * @dataProvider provideData
+     */
+    public function testFirstKey($expected, iterable $iterable): void
+    {
+        $result = Iter\first($iterable);
+
+        self::assertSame($expected, $result);
+    }
+
+    public function provideData(): iterable
+    {
+        yield [null, []];
+        yield [null, new \SplDoublyLinkedList()];
+        yield ['b', ['a' => 'b']];
+        yield ['a', ['a', 'b']];
+        yield ['a', new Collection\Vector(['a', 'b'])];
+        yield ['b', new Collection\Vector(['a' => 'b'])];
+        yield ['b', new Collection\Map(['a' => 'b'])];
+        yield [null, (static function () {
+            yield null => null;
+        })()];
+        yield [null, (static function () {
+            return;
+            yield;
+        })()];
+    }
 }

tests/Psl/Iter/FlattenTest.php

@@ -5,8 +5,41 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
+use Psl\Iter;
 
 class FlattenTest extends TestCase
 {
-    // TODO: add tests.
+    public function testFlatten(): void
+    {
+        $result = Iter\flatten([
+            [1, 2, 3],
+            new Collection\Map(['a' => 'b', 'c' => 'd', 'e' => 'f']),
+            (fn () => yield 'hey' => 'hello')()
+        ]);
+
+        static::assertSame([
+            0 => 1,
+            1 => 2,
+            2 => 3,
+            'a' => 'b',
+            'c' => 'd',
+            'e' => 'f',
+            'hey' => 'hello'
+        ], Iter\to_array_with_keys($result));
+    }
+
+    public function testFlattenSameKeys(): void
+    {
+        $result = Iter\flatten(new Collection\Vector([
+            new Collection\MutableMap(['a' => 'b']),
+            ['a' => 'foo']
+        ]));
+
+        static::assertSame('a', Iter\first_key($result));
+        static::assertSame('b', Iter\first($result));
+
+        static::assertSame('a', Iter\last_key($result));
+        static::assertSame('foo', Iter\last($result));
+    }
 }

tests/Psl/Iter/FlipTest.php

@@ -5,8 +5,28 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Collection;
+use Psl\Iter;
 
 class FlipTest extends TestCase
 {
-    // TODO: add tests.
+    public function testFlip(): void
+    {
+        $a = new Collection\MutableVector(['a', 'b']);
+        $b = new Collection\MutableVector(['c', 'd']);
+
+        $iterable = new Iter\Iterator(['a' => $a, 'b' => $b]);
+
+        static::assertSame('a', Iter\first_key($iterable));
+        static::assertSame($a, Iter\first($iterable));
+        static::assertSame('b', Iter\last_key($iterable));
+        static::assertSame($b, Iter\last($iterable));
+
+        $result = Iter\flip($iterable);
+
+        static::assertSame($a, Iter\first_key($result));
+        static::assertSame('a', Iter\first($result));
+        static::assertSame($b, Iter\last_key($result));
+        static::assertSame('b', Iter\last($result));
+    }
 }

tests/Psl/Iter/FromEntriesTest.php

@@ -5,8 +5,41 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Iter;
 
 class FromEntriesTest extends TestCase
 {
-    // TODO: add tests.
+    public function testEmptyEntries(): void
+    {
+        $actual = Iter\from_entries([]);
+        self::assertCount(0, $actual);
+    }
+
+    public function testFromEntries(): void
+    {
+        $actual = Iter\from_entries([
+            [1, 'hello'],
+            [2, 'world']
+        ]);
+
+        $array = Iter\to_array_with_keys($actual);
+
+        self::assertCount(2, $array);
+        self::assertSame('hello', $array[1]);
+        self::assertSame('world', $array[2]);
+    }
+
+    public function testFromEntriesWithNonArrayKeyKeys(): void
+    {
+        $actual = Iter\from_entries([
+            [['1', '2'], 'hello'],
+            [['3', '4'], 'world']
+        ]);
+
+        self::assertSame('hello', Iter\first($actual));
+        self::assertSame('world', Iter\last($actual));
+
+        self::assertSame(['1', '2'], Iter\first_key($actual));
+        self::assertSame(['3', '4'], Iter\last_key($actual));
+    }
 }

tests/Psl/Iter/FromKeysTest.php

@@ -5,8 +5,30 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Iter;
 
 class FromKeysTest extends TestCase
 {
-    // TODO: add tests.
+    public function testFromKeys(): void
+    {
+        $actual = Iter\from_keys(['hello', 'world'], fn (string $_key) => false);
+
+        self::assertSame('hello', Iter\first_key($actual));
+        self::assertSame('world', Iter\last_key($actual));
+        self::assertFalse(Iter\first($actual));
+        self::assertFalse(Iter\last($actual));
+    }
+
+    public function testFromKeysWithNonArrayKeyKeys(): void
+    {
+        $actual = Iter\from_keys([
+            [1, 'hello'],
+            [2, 'world']
+        ], fn (array $k) => $k[1]);
+
+        self::assertSame([1, 'hello'], Iter\first_key($actual));
+        self::assertSame([2, 'world'], Iter\last_key($actual));
+        self::assertSame('hello', Iter\first($actual));
+        self::assertSame('world', Iter\last($actual));
+    }
 }

tests/Psl/Iter/IsEmptyTest.php

@@ -5,8 +5,26 @@ declare(strict_types=1);
 namespace Psl\Tests\Iter;
 
 use PHPUnit\Framework\TestCase;
+use Psl\Iter;
 
 class IsEmptyTest extends TestCase
 {
-    // TODO: add tests.
+    /**
+     * @dataProvider provideData
+     */
+    public function testIsEmpty(bool $expected, iterable $iterable): void
+    {
+        self::assertSame($expected, Iter\is_empty($iterable));
+    }
+
+    public function provideData(): iterable
+    {
+        yield [true, []];
+        yield [true, Iter\from_entries([])];
+        yield [true, (fn () => yield from [])()];
+
+        yield [false, [null]];
+        yield [false, [false]];
+        yield [false, ['hello', 'world']];
+    }
 }

tests/Psl/Iter/RewindableTest.php

@@ -1,12 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Psl\Tests\Iter;
-
-use PHPUnit\Framework\TestCase;
-
-class RewindableTest extends TestCase
-{
-    // TODO: add tests.
-}