Both traceparent&servertiming for CodeIgniter, Yii, Laravel (#230)

src/HttpInstrumentation.php

@@ -78,6 +78,22 @@ public static function register(CachedInstrumentation $instrumentation): void
                     $span->setAttribute(TraceAttributes::HTTP_RESPONSE_STATUS_CODE, $response->getStatusCode());
                     $span->setAttribute(TraceAttributes::NETWORK_PROTOCOL_VERSION, $response->getProtocolVersion());
                     $span->setAttribute(TraceAttributes::HTTP_RESPONSE_BODY_SIZE, $response->headers->get('Content-Length'));
+
+                    // Propagate server-timing header to response, if ServerTimingPropagator is present
+                    if (class_exists('OpenTelemetry\Contrib\Propagation\ServerTiming\ServerTimingPropagator')) {
+                        /** @phan-suppress-next-line PhanUndeclaredClassMethod */
+                        $prop = new \OpenTelemetry\Contrib\Propagation\ServerTiming\ServerTimingPropagator();
+                        /** @phan-suppress-next-line PhanUndeclaredClassMethod */
+                        $prop->inject($response, ResponsePropagationSetter::instance(), $scope->context());
+                    }
+
+                    // Propagate traceresponse header to response, if TraceResponsePropagator is present
+                    if (class_exists('OpenTelemetry\Contrib\Propagation\TraceResponse\TraceResponsePropagator')) {
+                        /** @phan-suppress-next-line PhanUndeclaredClassMethod */
+                        $prop = new \OpenTelemetry\Contrib\Propagation\TraceResponse\TraceResponsePropagator();
+                        /** @phan-suppress-next-line PhanUndeclaredClassMethod */
+                        $prop->inject($response, ResponsePropagationSetter::instance(), $scope->context());
+                    }
                 }
 
                 $span->end();

src/ResponsePropagationSetter.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\Contrib\Instrumentation\Laravel;
+
+use function assert;
+use Illuminate\Http\Response;
+use OpenTelemetry\Context\Propagation\PropagationSetterInterface;
+
+/**
+ * @internal
+ */
+class ResponsePropagationSetter implements PropagationSetterInterface
+{
+    public static function instance(): self
+    {
+        static $instance;
+
+        return $instance ??= new self();
+    }
+
+    public function set(&$carrier, string $key, string $value): void
+    {
+        assert($carrier instanceof Response);
+
+        $carrier->headers->set($key, $value);
+    }
+}