ref(tracing): keep old span name as op instead of default (#905)

Author: lcian

CHANGELOG.md

@@ -6,9 +6,10 @@
 
 - ref(tracing): rework tracing to Sentry span name/op conversion ([#887](https://github.com/getsentry/sentry-rust/pull/887)) by @lcian
   - The `tracing` integration now uses the tracing span name as the Sentry span name by default.
-  - Before this change, the span name would be set based on the `tracing` span target (<module>::<function> when using the `tracing::instrument` macro).
-  - The `tracing` integration now uses `default` as the default Sentry span op.
+  - Before this change, the span name would be set based on the `tracing` span target (`<module>::<function>` when using the `tracing::instrument` macro).
+  - The `tracing` integration now uses `<span target>::<span name>` as the default Sentry span op (i.e. `<module>::<function>` when using `tracing::instrument`).
   - Before this change, the span op would be set based on the `tracing` span name.
+  - Read below to learn how to customize the span name and op.
   - When upgrading, please ensure to adapt any queries, metrics or dashboards to use the new span names/ops.
 - ref(tracing): use standard code attributes ([#899](https://github.com/getsentry/sentry-rust/pull/899)) by @lcian
   - Logs now carry the attributes `code.module.name`, `code.file.path` and `code.line.number` standardized in OTEL to surface the respective information, in contrast with the previously sent `tracing.module_path`, `tracing.file` and `tracing.line`.

sentry-tracing/src/layer.rs

@@ -303,22 +303,23 @@ where
 
         let (data, sentry_name, sentry_op, sentry_trace) = extract_span_data(attrs);
         let sentry_name = sentry_name.as_deref().unwrap_or_else(|| span.name());
-        let sentry_op = sentry_op.as_deref().unwrap_or("default");
+        let sentry_op =
+            sentry_op.unwrap_or_else(|| format!("{}::{}", span.metadata().target(), span.name()));
 
         let hub = sentry_core::Hub::current();
         let parent_sentry_span = hub.configure_scope(|scope| scope.get_span());
 
         let mut sentry_span: sentry_core::TransactionOrSpan = match &parent_sentry_span {
-            Some(parent) => parent.start_child(sentry_op, sentry_name).into(),
+            Some(parent) => parent.start_child(&sentry_op, sentry_name).into(),
             None => {
                 let ctx = if let Some(trace_header) = sentry_trace {
                     sentry_core::TransactionContext::continue_from_headers(
                         sentry_name,
-                        sentry_op,
+                        &sentry_op,
                         [("sentry-trace", trace_header.as_str())],
                     )
                 } else {
-                    sentry_core::TransactionContext::new(sentry_name, sentry_op)
+                    sentry_core::TransactionContext::new(sentry_name, &sentry_op)
                 };
 
                 let tx = sentry_core::start_transaction(ctx);

sentry-tracing/tests/smoke.rs

@@ -24,7 +24,7 @@ fn should_instrument_function_with_event() {
         sentry::protocol::Context::Trace(trace) => trace,
         unexpected => panic!("Expected trace context but got {unexpected:?}"),
     };
-    assert_eq!(trace.op.as_deref().unwrap(), "default");
+    assert_eq!(trace.op.as_deref().unwrap(), "smoke::function_with_tags");
 
     //Confirm transaction values
     let transaction = data.get(1).expect("should have 1 transaction");