Fix Debug.Assert failures in SpeedScope tests and DynamicTraceEventParser by brianrob · Pull Request #2368 · microsoft/perfview

brianrob · 2026-02-20T21:40:22Z

The SpeedScope CanConvertProvidedTraceFiles tests were clearing Trace.Listeners to suppress Debug.Assert failures that fired during trace parsing. This masked two real bugs:

Fix 1: Duplicate template enumeration in DynamicTraceEventParser

DynamicTraceEventParser.EnumerateTemplates enumerates templates from three sources (manifest-based, registeredParser, and eventPipeTraceEventParser) but only deduplicated between manifest-based templates and registeredParser. When both registeredParser and eventPipeTraceEventParser knew about the same event, the template was enumerated twice, causing Subscribe to assert on the duplicate with mayHaveExistedBefore=false.

Fix: Filter eventPipeTraceEventParser templates against registeredParser, matching the existing dedup pattern for manifest-based templates.

Fix 2: Skip ConfirmAllEventsAreInEnumeration for ApplicationServerTraceEventParser

ApplicationServerTraceEventParser is auto-generated and has many events that share the same task name and opcode, producing duplicate computed event names (100+ duplicates). The ConfirmAllEventsAreInEnumeration DEBUG validation cannot handle this pattern.

Fix: Skip this parser from the validation, similar to how PredefinedDynamicTraceEventParser is already excluded.

Cleanup

Remove the listener-clearing hack from SpeedScope tests (no longer needed since the underlying asserts are fixed).
Add documentation to ThrowingTraceListener and DebugAssertionTests explaining that on .NET 5+, the DefaultTraceListener already throws on assert failures, so no additional listener configuration is needed.

brianrob · 2026-02-20T21:40:37Z

/azp run

azure-pipelines · 2026-02-20T21:40:46Z