[APMSVLS-197] test: Add unit tests for event.request.headers trace context extraction

Author: Dogbu-cyber

bottlecap/src/lifecycle/invocation/processor.rs

@@ -1846,4 +1846,295 @@ mod tests {
             "Should be snapstart span (id=3), not cold start span (id=2)"
         );
     }
+
+    #[test]
+    fn test_extract_span_context_from_event_request_headers_datadog() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "request": {
+                "headers": {
+                    "x-datadog-trace-id": "1234567890",
+                    "x-datadog-parent-id": "9876543210",
+                    "x-datadog-sampling-priority": "2",
+                    "x-datadog-origin": "rum"
+                }
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(result.is_some());
+        let context = result.unwrap();
+        assert_eq!(context.trace_id, 1_234_567_890);
+        assert_eq!(context.span_id, 9_876_543_210);
+        assert_eq!(context.sampling.unwrap().priority, Some(2));
+        assert_eq!(context.origin, Some("rum".to_string()));
+    }
+
+    #[test]
+    fn test_extract_span_context_from_event_request_headers_tracecontext() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "request": {
+                "headers": {
+                    "traceparent": "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01",
+                    "tracestate": "dd=s:2;o:rum"
+                }
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(result.is_some());
+        let context = result.unwrap();
+        assert_eq!(context.sampling.unwrap().priority, Some(2));
+        assert_eq!(context.origin, Some("rum".to_string()));
+    }
+
+    #[test]
+    fn test_extract_span_context_priority_order() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+
+        let mut headers = HashMap::new();
+        headers.insert(DATADOG_TRACE_ID_KEY.to_string(), "111".to_string());
+        headers.insert(DATADOG_PARENT_ID_KEY.to_string(), "222".to_string());
+
+        let payload = json!({
+            "headers": {
+                "x-datadog-trace-id": "333",
+                "x-datadog-parent-id": "444"
+            },
+            "request": {
+                "headers": {
+                    "x-datadog-trace-id": "555",
+                    "x-datadog-parent-id": "666"
+                }
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(result.is_some());
+        let context = result.unwrap();
+        assert_eq!(
+            context.trace_id, 333,
+            "Should prioritize event.headers over other sources"
+        );
+    }
+
+    #[test]
+    fn test_extract_span_context_fallback_to_request_headers() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "argumentsMap": {
+                "id": "123"
+            },
+            "request": {
+                "headers": {
+                    "x-datadog-trace-id": "7777",
+                    "x-datadog-parent-id": "8888",
+                    "x-datadog-sampling-priority": "1"
+                }
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(result.is_some(), "Should fallback to event.request.headers");
+        let context = result.unwrap();
+        assert_eq!(context.trace_id, 7777);
+        assert_eq!(context.span_id, 8888);
+        assert_eq!(context.sampling.unwrap().priority, Some(1));
+    }
+
+    #[test]
+    fn test_extract_span_context_no_request_headers() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "argumentsMap": {
+                "id": "123"
+            },
+            "request": {
+                "body": "some body"
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(
+            result.is_none(),
+            "Should return None when no trace context found"
+        );
+    }
+
+    #[test]
+    fn test_extract_span_context_empty_request_headers() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "request": {
+                "headers": {}
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(
+            result.is_none(),
+            "Should return None when request.headers is empty"
+        );
+    }
+
+    #[test]
+    fn test_extract_span_context_invalid_request_headers() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "request": {
+                "headers": {
+                    "x-datadog-trace-id": "not-a-number",
+                    "x-datadog-parent-id": "also-not-a-number"
+                }
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(
+            result.is_none(),
+            "Should return None when headers are invalid"
+        );
+    }
+
+    #[test]
+    fn test_extract_span_context_appsync_real_world_example() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "arguments": {
+                "userId": "12345"
+            },
+            "identity": {
+                "sub": "user-sub-id"
+            },
+            "request": {
+                "headers": {
+                    "x-datadog-trace-id": "123456789012345",
+                    "x-datadog-parent-id": "98765432109876",
+                    "x-datadog-sampling-priority": "2",
+                    "x-datadog-origin": "rum",
+                    "x-datadog-tags": "_dd.p.dm=-0",
+                    "user-agent": "Mozilla/5.0",
+                    "content-type": "application/json"
+                }
+            },
+            "info": {
+                "fieldName": "getUser",
+                "parentTypeName": "Query"
+            }
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(
+            result.is_some(),
+            "Should extract from real-world AppSync event"
+        );
+        let context = result.unwrap();
+        assert_eq!(context.trace_id, 123_456_789_012_345);
+        assert_eq!(context.span_id, 98_765_432_109_876);
+        assert_eq!(context.sampling.unwrap().priority, Some(2));
+        assert_eq!(context.origin, Some("rum".to_string()));
+    }
+
+    #[test]
+    fn test_extract_span_context_request_not_an_object() {
+        let config = Arc::new(config::Config {
+            trace_propagation_style_extract: vec![
+                config::trace_propagation_style::TracePropagationStyle::Datadog,
+                config::trace_propagation_style::TracePropagationStyle::TraceContext,
+            ],
+            ..config::Config::default()
+        });
+        let propagator = Arc::new(DatadogCompositePropagator::new(Arc::clone(&config)));
+        let headers = HashMap::new();
+
+        let payload = json!({
+            "request": "invalid-not-an-object"
+        });
+
+        let result = Processor::extract_span_context(&headers, &payload, propagator);
+
+        assert!(
+            result.is_none(),
+            "Should handle gracefully when request is not an object"
+        );
+    }
 }