MDL-82627 PHPUnit: Add helper to mock http_client

lib/phpunit/classes/advanced_testcase.php

@@ -16,6 +16,10 @@
 
 use core\di;
 use core\hook;
+use core\http_client;
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Middleware;
 
 /**
  * Advanced PHPUnit test case customised for Moodle.
@@ -878,4 +882,31 @@ abstract class advanced_testcase extends base_testcase {
 
         require_once(static::get_fixture_path($component, $path));
     }
+
+    /**
+     * Get a mocked HTTP Client, inserting it into the Dependency Injector.
+     *
+     * @param array|null $history An array which will contain the Request/Response history of the HTTP client
+     * @return array Containing the client, the mock, and the history
+     */
+    protected function get_mocked_http_client(
+        ?array &$history = null,
+    ): array {
+        $mock = new MockHandler([]);
+        $handlerstack = HandlerStack::create($mock);
+
+        if ($history !== null) {
+            $historymiddleware = Middleware::history($history);
+            $handlerstack->push($historymiddleware);
+        }
+        $client = new http_client(['handler' => $handlerstack]);
+
+        di::set(http_client::class, $client);
+
+        return [
+            'client' => $client,
+            'mock' => $mock,
+            'handlerstack' => $handlerstack,
+        ];
+    }
 }