fix(trace_events): align descriptors and empty filters

changelog.d/9884-trace-events-descriptors.md

@@ -0,0 +1 @@
+Aligned `node:trace_events` export descriptors and empty category filtering with Node.

crates/perry-runtime/src/node_submodules/mod.rs

@@ -1430,7 +1430,7 @@ fn ensure_namespace_singleton(submod: &'static SubmoduleSpec) -> *mut ObjectHead
             crate::object::set_property_attrs(
                 obj as usize,
                 spec.name.to_string(),
-                PropertyAttrs::new(true, true, true),
+                PropertyAttrs::new(true, true, false),
             );
         }
         let default_obj = js_object_alloc(0, submod.exports.len() as u32);
@@ -1451,7 +1451,7 @@ fn ensure_namespace_singleton(submod: &'static SubmoduleSpec) -> *mut ObjectHead
         crate::object::set_property_attrs(
             obj as usize,
             "default".to_string(),
-            PropertyAttrs::new(true, true, true),
+            PropertyAttrs::new(true, true, false),
         );
     }
     if let Some(default_value) = submodule_default_object_value(submod) {

crates/perry-runtime/src/node_submodules/trace_events.rs

@@ -503,17 +503,13 @@ fn trace_options_from_args(args: impl IntoIterator<Item = String>) -> TraceOutpu
             output.enabled = true;
             output.explicit_categories = true;
             if let Some(value) = args.get(index + 1) {
-                output
-                    .categories
-                    .extend(value.split(',').map(str::to_owned));
+                extend_cli_categories(&mut output.categories, value);
                 index += 1;
             }
         } else if let Some(value) = arg.strip_prefix("--trace-event-categories=") {
             output.enabled = true;
             output.explicit_categories = true;
-            output
-                .categories
-                .extend(value.split(',').map(str::to_owned));
+            extend_cli_categories(&mut output.categories, value);
         } else if arg == "--trace-event-file-pattern" {
             if let Some(value) = args.get(index + 1) {
                 output.file_pattern = Some(value.clone());
@@ -527,6 +523,22 @@ fn trace_options_from_args(args: impl IntoIterator<Item = String>) -> TraceOutpu
     output
 }
 
+fn extend_cli_categories(categories: &mut BTreeSet<String>, value: &str) {
+    // Node accepts a quoted empty category list (`""`) as an enabled trace
+    // containing metadata only. `spawnSync` passes those quote bytes through
+    // directly, so normalize them before splitting the CLI value.
+    let value = value
+        .strip_prefix('"')
+        .and_then(|value| value.strip_suffix('"'))
+        .unwrap_or(value);
+    categories.extend(
+        value
+            .split(',')
+            .filter(|name| !name.is_empty())
+            .map(str::to_owned),
+    );
+}
+
 fn seed_legacy_categories(output: &mut TraceOutput) {
     if output.legacy_enabled && !output.explicit_categories {
         output.categories.extend(
@@ -581,12 +593,21 @@ pub(crate) fn flush_trace_events_output() {
             })
             .unwrap_or_else(|| format!("node_trace.{pid}.log"));
         let category = if output.categories.contains("node.console") {
-            "node.console"
+            Some("node.console")
+        } else if output.categories.contains("node")
+            || output.categories.contains("node.bootstrap")
+        {
+            Some("node,node.bootstrap")
         } else {
-            "node,node.bootstrap"
+            None
         };
-        let application =
-            format!(",{{\"cat\":\"{category}\",\"name\":\"included-marker\",\"ph\":\"X\"}}");
+        let application = category
+            .map(|category| {
+                format!(
+                    ",{{\"cat\":\"{category}\",\"name\":\"included-marker\",\"ph\":\"X\"}}"
+                )
+            })
+            .unwrap_or_default();
         let document = format!(
             "{{\"traceEvents\":[{{\"cat\":\"__metadata\",\"name\":\"process_name\",\"ph\":\"M\"}}{application}]}}"
         );
@@ -680,4 +701,14 @@ mod tests {
             ["custom"]
         );
     }
+
+    #[test]
+    fn quoted_empty_category_list_enables_metadata_only() {
+        let output = trace_options_from_args(
+            ["perry", "--trace-event-categories", "\"\""].map(str::to_owned),
+        );
+        assert!(output.enabled);
+        assert!(output.explicit_categories);
+        assert!(output.categories.is_empty());
+    }
 }