Requests: Add "multiple.request.before_request_multiple" hook

docs/hooks.md

@@ -53,6 +53,12 @@ Available Hooks
     Parameters: `WpOrg\Requests\Response &$return`, `array &$req_headers`,
     `array &$req_data`, `array &$options`
 
+* **`multiple.request.before_request_multiple`**
+
+    Alter the request before it is sent to the transport.
+
+    Parameters: `array &$request, string|int $id`
+
 * **`multiple.request.complete`**
 
     Alter the response for an individual request in a multi-request.

src/Requests.php

@@ -586,6 +586,8 @@ public static function request_multiple($requests, $options = []) {
 					$request['options']['hooks']->register('multiple.request.complete', $request['options']['complete']);
 				}
 			}
+
+			$options['hooks']->dispatch('multiple.request.before_request_multiple', [&$request, $id]);
 		}
 
 		unset($request);

tests/RequestsTest.php

@@ -153,6 +153,43 @@ public function testRequestMultipleInvalidOptions($input) {
 		Requests::request_multiple([], $input);
 	}
 
+	public function testRequestMultipleTriggersRequestsFailedCallback() {
+		$mock = $this->getMockBuilder(stdClass::class)->setMethods(['before_request_multiple'])->getMock();
+		$mock->expects($this->exactly(2))->method('before_request_multiple');
+		$hooks = new Hooks();
+		$hooks->register('multiple.request.before_request_multiple', [ $mock, 'before_request_multiple' ]);
+
+		$transport = new TransportMock();
+
+		$options = [
+			'hooks'     => $hooks,
+			'transport' => $transport,
+		];
+
+		$requests = [
+			'test' => [
+				'url' => 'http://test-url.com',
+				'options' => [
+					'mock.code'        => 200,
+					'mock.chunked'     => false,
+					'mock.body'        => 'Test Body',
+					'mock.raw_headers' => '',
+				]
+			],
+			'test2' => [
+				'url' => 'http://test-url.com',
+				'options' => [
+					'mock.code'        => 200,
+					'mock.chunked'     => false,
+					'mock.body'        => 'Test Body',
+					'mock.raw_headers' => '',
+				]
+			]
+		];
+
+		Requests::request_multiple($requests, $options);
+	}
+
 	/**
 	 * Data Provider.
 	 *