fix(laravel): queue spans per request signature in ClientRequestWatcher

src/Instrumentation/Laravel/src/Watchers/ClientRequestWatcher.php

@@ -23,7 +23,7 @@
 class ClientRequestWatcher extends Watcher
 {
     /**
-     * @var array<string, SpanInterface>
+     * @var array<string, list<SpanInterface>>
      */
     protected array $spans = [];
 
@@ -67,31 +67,25 @@ public function recordRequest(RequestSending $request): void
                 ServerAttributes::SERVER_PORT => $parsedUrl['port'] ?? '',
             ])
             ->startSpan();
-        $this->spans[$this->createRequestComparisonHash($request->request)] = $span;
+        $this->spans[$this->createRequestComparisonHash($request->request)][] = $span;
     }
 
     /** @psalm-suppress PossiblyUnusedMethod */
     public function recordConnectionFailed(ConnectionFailed $request): void
     {
-        $requestHash = $this->createRequestComparisonHash($request->request);
-
-        $span = $this->spans[$requestHash] ?? null;
+        $span = $this->shiftSpan($this->createRequestComparisonHash($request->request));
         if (null === $span) {
             return;
         }
 
         $span->setStatus(StatusCode::STATUS_ERROR, 'Connection failed');
         $span->end();
-
-        unset($this->spans[$requestHash]);
     }
 
     /** @psalm-suppress PossiblyUnusedMethod */
     public function recordResponse(ResponseReceived $request): void
     {
-        $requestHash = $this->createRequestComparisonHash($request->request);
-
-        $span = $this->spans[$requestHash] ?? null;
+        $span = $this->shiftSpan($this->createRequestComparisonHash($request->request));
         if (null === $span) {
             return;
         }
@@ -103,15 +97,28 @@ public function recordResponse(ResponseReceived $request): void
 
         $this->maybeRecordError($span, $request->response);
         $span->end();
-
-        unset($this->spans[$requestHash]);
     }
 
     private function createRequestComparisonHash(Request $request): string
     {
         return sha1($request->method() . '|' . $request->url() . '|' . $request->body());
     }
 
+    private function shiftSpan(string $requestHash): ?SpanInterface
+    {
+        if (empty($this->spans[$requestHash])) {
+            return null;
+        }
+
+        $span = array_shift($this->spans[$requestHash]);
+
+        if (empty($this->spans[$requestHash])) {
+            unset($this->spans[$requestHash]);
+        }
+
+        return $span;
+    }
+
     private function maybeRecordError(SpanInterface $span, Response $response): void
     {
         if ($response->successful()) {

src/Instrumentation/Laravel/tests/Integration/Http/ClientTest.php

@@ -6,10 +6,18 @@
 
 use GuzzleHttp\Exception\ConnectException;
 use GuzzleHttp\Promise\RejectedPromise;
+use GuzzleHttp\Psr7\Request as Psr7Request;
+use GuzzleHttp\Psr7\Response as Psr7Response;
+use Illuminate\Http\Client\Events\ConnectionFailed;
+use Illuminate\Http\Client\Events\ResponseReceived;
+use Illuminate\Http\Client\Pool;
 use Illuminate\Http\Client\Request;
+use Illuminate\Http\Client\Response;
+use Illuminate\Support\Facades\Event;
 use Illuminate\Support\Facades\Http;
 use OpenTelemetry\API\Trace\StatusCode;
 use OpenTelemetry\SDK\Trace\StatusData;
+use OpenTelemetry\SemConv\Attributes\HttpAttributes;
 use OpenTelemetry\SemConv\Attributes\UrlAttributes;
 use OpenTelemetry\Tests\Contrib\Instrumentation\Laravel\Integration\TestCase;
 
@@ -60,4 +68,51 @@ public function test_it_records_connection_failures(): void
         self::assertEquals('http://fail', $span->getAttributes()->get(UrlAttributes::URL_FULL));
         self::assertEquals(StatusData::create(StatusCode::STATUS_ERROR, 'Connection failed'), $span->getStatus());
     }
+
+    public function test_it_matches_spans_to_responses_for_concurrent_identical_requests(): void
+    {
+        Http::fake([
+            'same.opentelemetry.io' => Http::sequence()
+                ->push(status: 200)
+                ->push(status: 500),
+        ]);
+
+        $responses = Http::pool(fn (Pool $pool) => [
+            $pool->get('same.opentelemetry.io'),
+            $pool->get('same.opentelemetry.io'),
+        ]);
+
+        self::assertEquals(200, $responses[0]->status());
+        self::assertEquals(500, $responses[1]->status());
+
+        self::assertCount(2, $this->storage);
+
+        $firstSpan = $this->storage[0];
+        $secondSpan = $this->storage[1];
+
+        self::assertEquals(200, $firstSpan->getAttributes()->get(HttpAttributes::HTTP_RESPONSE_STATUS_CODE));
+        self::assertEquals(StatusCode::STATUS_UNSET, $firstSpan->getStatus()->getCode());
+
+        self::assertEquals(500, $secondSpan->getAttributes()->get(HttpAttributes::HTTP_RESPONSE_STATUS_CODE));
+        self::assertEquals(StatusCode::STATUS_ERROR, $secondSpan->getStatus()->getCode());
+    }
+
+    public function test_it_ignores_response_with_no_matching_request(): void
+    {
+        $request = new Request(new Psr7Request('GET', 'http://untracked.opentelemetry.io'));
+        $response = new Response(new Psr7Response(200));
+
+        Event::dispatch(new ResponseReceived($request, $response));
+
+        self::assertCount(0, $this->storage);
+    }
+
+    public function test_it_ignores_connection_failure_with_no_matching_request(): void
+    {
+        $request = new Request(new Psr7Request('GET', 'http://untracked.opentelemetry.io'));
+
+        Event::dispatch(new ConnectionFailed($request));
+
+        self::assertCount(0, $this->storage);
+    }
 }