Inital commit after splitting from project

tests/TransposeTest.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tez\Utils\Tests\Arr;
+
+use PHPUnit\Framework\TestCase;
+use Tez\Utils\Arr\Transpose;
+
+final class TransposeTest extends TestCase
+{
+    public function testTransposesMatrix(): void
+    {
+        $result = Transpose::matrix([
+            [1, 2, 3],
+            [4, 5, 6],
+        ]);
+
+        self::assertSame([[1, 4], [2, 5], [3, 6]], $result);
+    }
+
+    public function testTransposesSquareMatrix(): void
+    {
+        $result = Transpose::matrix([
+            [1, 2],
+            [3, 4],
+        ]);
+
+        self::assertSame([[1, 3], [2, 4]], $result);
+    }
+
+    public function testTransposesSingleRow(): void
+    {
+        $result = Transpose::matrix([[1, 2, 3]]);
+
+        self::assertSame([[1], [2], [3]], $result);
+    }
+
+    public function testTransposesSingleColumn(): void
+    {
+        $result = Transpose::matrix([[1], [2], [3]]);
+
+        self::assertSame([[1, 2, 3]], $result);
+    }
+
+    public function testEmptyInputReturnsEmpty(): void
+    {
+        self::assertSame([], Transpose::matrix([]));
+    }
+
+    public function testAssociativeKeysAreStripped(): void
+    {
+        $result = Transpose::matrix([
+            ['a' => 1, 'b' => 2],
+            ['a' => 3, 'b' => 4],
+        ]);
+
+        self::assertSame([[1, 3], [2, 4]], $result);
+    }
+
+    public function testJaggedArrayThrows(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+
+        Transpose::matrix([[1, 2, 3], [4, 5]]);
+    }
+}