Fix: ignore redirection error (#291)

Author: MilesChou

src/Watchers/ClientRequestWatcher.php

@@ -112,6 +112,12 @@ private function maybeRecordError(SpanInterface $span, Response $response): void
             return;
         }
 
+        // HTTP status code 3xx is not really error
+        // See https://www.rfc-editor.org/rfc/rfc9110.html#name-redirection-3xx
+        if ($response->redirect()) {
+            return;
+        }
+
         $span->setStatus(
             StatusCode::STATUS_ERROR,
             HttpResponse::$statusTexts[$response->status()] ?? (string) $response->status()

tests/Integration/Http/ClientTest.php

@@ -20,19 +20,29 @@ public function test_it_records_requests(): void
         Http::fake([
             'ok.opentelemetry.io/*' => Http::response(status: 201),
             'missing.opentelemetry.io' => Http::response(status: 404),
+            'redirect.opentelemetry.io' => Http::response(status: 302),
         ]);
 
         $response = Http::get('missing.opentelemetry.io');
         $span = $this->storage[0];
         self::assertEquals(404, $response->status());
         self::assertEquals('GET', $span->getName());
         self::assertEquals('missing.opentelemetry.io', $span->getAttributes()->get(TraceAttributes::URL_PATH));
+        self::assertEquals(StatusCode::STATUS_ERROR, $span->getStatus()->getCode());
 
         $response = Http::post('ok.opentelemetry.io/foo?param=bar');
         $span = $this->storage[1];
         self::assertEquals(201, $response->status());
         self::assertEquals('POST', $span->getName());
         self::assertEquals('ok.opentelemetry.io/foo', $span->getAttributes()->get(TraceAttributes::URL_PATH));
+        self::assertEquals(StatusCode::STATUS_UNSET, $span->getStatus()->getCode());
+
+        $response = Http::get('redirect.opentelemetry.io');
+        $span = $this->storage[2];
+        self::assertEquals(302, $response->status());
+        self::assertEquals('GET', $span->getName());
+        self::assertEquals('redirect.opentelemetry.io', $span->getAttributes()->get(TraceAttributes::URL_PATH));
+        self::assertEquals(StatusCode::STATUS_UNSET, $span->getStatus()->getCode());
     }
 
     public function test_it_records_connection_failures(): void