Add comprehensive unit tests for MetaLog Response

tests/Unit/Api/MetaLog/MetaLogResponseTest.php

@@ -0,0 +1,197 @@
+<?php
+declare( strict_types=1 );
+
+namespace WooCommerce\Facebook\Tests\Unit\API\MetaLog;
+
+use WooCommerce\Facebook\API\MetaLog\Response;
+use WooCommerce\Facebook\API\Response as ApiResponse;
+use WooCommerce\Facebook\Tests\AbstractWPUnitTestWithOptionIsolationAndSafeFiltering;
+
+/**
+ * Unit tests for MetaLog Response class.
+ *
+ * @since 3.5.2
+ */
+class MetaLogResponseTest extends AbstractWPUnitTestWithOptionIsolationAndSafeFiltering {
+
+	/**
+	 * Test that the class exists and can be instantiated.
+	 */
+	public function test_class_exists() {
+		$this->assertTrue( class_exists( Response::class ) );
+	}
+
+	/**
+	 * Test that Response extends ApiResponse.
+	 */
+	public function test_extends_api_response() {
+		$response = new Response( '' );
+		$this->assertInstanceOf( ApiResponse::class, $response );
+	}
+
+	/**
+	 * Test instantiation with JSON response data.
+	 */
+	public function test_instantiation_with_json_data() {
+		$data = json_encode( [ 'success' => true, 'id' => '12345' ] );
+		$response = new Response( $data );
+
+		$this->assertInstanceOf( Response::class, $response );
+		$this->assertEquals( $data, $response->to_string() );
+	}
+
+	/**
+	 * Test inherited to_string method.
+	 */
+	public function test_to_string_method() {
+		$raw_data = '{"test":"data"}';
+		$response = new Response( $raw_data );
+
+		$this->assertEquals( $raw_data, $response->to_string() );
+	}
+
+	/**
+	 * Test accessing response data via magic getter.
+	 */
+	public function test_magic_getter_access() {
+		$data = [ 'key' => 'value', 'number' => 123 ];
+		$json = json_encode( $data );
+		$response = new Response( $json );
+
+		$this->assertEquals( 'value', $response->key );
+		$this->assertEquals( 123, $response->number );
+	}
+
+	/**
+	 * Test with complex nested data.
+	 */
+	public function test_with_nested_data() {
+		$data = [
+			'success' => true,
+			'data' => [
+				'items' => [ 'item1', 'item2' ],
+				'meta' => [
+					'count' => 2,
+					'page' => 1
+				]
+			]
+		];
+		$json = json_encode( $data );
+		$response = new Response( $json );
+
+		$this->assertTrue( $response->success );
+		$this->assertIsArray( $response->data['items'] );
+		$this->assertEquals( 2, $response->data['meta']['count'] );
+	}
+
+	/**
+	 * Test with invalid JSON data.
+	 */
+	public function test_with_invalid_json() {
+		$invalid_json = '{"invalid": json}';
+		$response = new Response( $invalid_json );
+
+		// Invalid JSON results in null response_data
+		$this->assertNull( $response->response_data );
+	}
+
+	/**
+	 * Test with empty string response.
+	 */
+	public function test_with_empty_string() {
+		$response = new Response( '' );
+
+		$this->assertEquals( '', $response->to_string() );
+		$this->assertNull( $response->response_data );
+	}
+
+	/**
+	 * Test with null-like response.
+	 */
+	public function test_with_null_string() {
+		$response = new Response( 'null' );
+
+		$this->assertNull( $response->response_data );
+	}
+
+	/**
+	 * Test with boolean response.
+	 */
+	public function test_with_boolean_response() {
+		$response_true = new Response( 'true' );
+		$response_false = new Response( 'false' );
+
+		$this->assertTrue( $response_true->response_data );
+		$this->assertFalse( $response_false->response_data );
+	}
+
+	/**
+	 * Test with numeric response.
+	 */
+	public function test_with_numeric_response() {
+		$response = new Response( '42' );
+
+		$this->assertEquals( 42, $response->response_data );
+	}
+
+	/**
+	 * Test with array response.
+	 */
+	public function test_with_array_response() {
+		$response = new Response( '["item1", "item2", "item3"]' );
+
+		$this->assertIsArray( $response->response_data );
+		$this->assertCount( 3, $response->response_data );
+		$this->assertEquals( 'item1', $response->response_data[0] );
+	}
+
+	/**
+	 * Test with Unicode characters.
+	 */
+	public function test_with_unicode_characters() {
+		$data = [ 'message' => '你好世界 🌍 émojis' ];
+		$json = json_encode( $data );
+		$response = new Response( $json );
+
+		$this->assertEquals( '你好世界 🌍 émojis', $response->message );
+	}
+
+	/**
+	 * Test with special characters.
+	 */
+	public function test_with_special_characters() {
+		$data = [ 'text' => "Line1\nLine2\tTabbed\r\nWindows" ];
+		$json = json_encode( $data );
+		$response = new Response( $json );
+
+		$this->assertEquals( "Line1\nLine2\tTabbed\r\nWindows", $response->text );
+	}
+
+	/**
+	 * Test response with large data set.
+	 */
+	public function test_with_large_dataset() {
+		$large_array = array_fill( 0, 1000, 'test_value' );
+		$data = [ 'items' => $large_array ];
+		$json = json_encode( $data );
+		$response = new Response( $json );
+
+		$this->assertCount( 1000, $response->items );
+	}
+
+	/**
+	 * Test that the class has no additional public methods.
+	 */
+	public function test_no_additional_public_methods() {
+		$reflection = new \ReflectionClass( Response::class );
+		$public_methods = $reflection->getMethods( \ReflectionMethod::IS_PUBLIC );
+
+		// Filter out inherited methods
+		$own_methods = array_filter( $public_methods, function( $method ) {
+			return $method->getDeclaringClass()->getName() === Response::class;
+		} );
+
+		// Should have no methods of its own (empty class extending ApiResponse)
+		$this->assertCount( 0, $own_methods );
+	}
+}