assertTrue(is_assoc(['test' => 'value'])); } public function testIsAssocReturnsFalseOnIndexedArray(): void { $this->assertFalse(is_assoc(['one', 'two', 'three'])); } public function testIsAssocReturnsTrueOnMixedArray(): void { $this->assertTrue(is_assoc(['one', 'two', 'three' => 'value'])); } public function testArrayFindReturnsCorrectElement(): void { $arr = [ [ 'id' => 1 ], [ 'id' => 2 ], [ 'id' => 3 ], ]; $this->assertSame($arr[0], array_find($arr, fn($element) => $element['id'] === 1)); } public function testArrayFieldsReturnsStrippedArray(): void { $arr = [ 'name' => 'John', 'email' => 'john@example.org', ]; $stripped = array_fields($arr, ['name']); $this->assertArrayHasKey('name', $stripped); $this->assertArrayNotHasKey('email', $stripped); } }