[HttpClient] Improve MockHttpClient exception message

Author: fancyweb

MockHttpClient.php

@@ -72,7 +72,7 @@ public function request(string $method, string $url, array $options = []): Respo
         } elseif (\is_callable($this->responseFactory)) {
             $response = ($this->responseFactory)($method, $url, $options);
         } elseif (!$this->responseFactory->valid()) {
-            throw new TransportException('The response factory iterator passed to MockHttpClient is empty.');
+            throw new TransportException($this->requestsCount ? 'No more response left in the response factory iterator passed to MockHttpClient: the number of requests exceeds the number of responses.' : 'The response factory iterator passed to MockHttpClient is empty.');
         } else {
             $responseFactory = $this->responseFactory->current();
             $response = \is_callable($responseFactory) ? $responseFactory($method, $url, $options) : $responseFactory;

Tests/MockHttpClientTest.php

@@ -527,4 +527,23 @@ public function testCancelingMockResponseExecutesOnProgressWithUpdatedInfo()
 
         $this->assertTrue($canceled);
     }
+
+    public function testEmptyResponseFactory()
+    {
+        $this->expectException(TransportException::class);
+        $this->expectExceptionMessage('The response factory iterator passed to MockHttpClient is empty.');
+
+        $client = new MockHttpClient([]);
+        $client->request('GET', 'https://example.com');
+    }
+
+    public function testMoreRequestsThanResponseFactoryResponses()
+    {
+        $this->expectException(TransportException::class);
+        $this->expectExceptionMessage('No more response left in the response factory iterator passed to MockHttpClient: the number of requests exceeds the number of responses.');
+
+        $client = new MockHttpClient([new MockResponse()]);
+        $client->request('GET', 'https://example.com');
+        $client->request('GET', 'https://example.com');
+    }
 }