When testing telemetry, pub/sub, or any broadcast mechanism with
async: true, events from concurrent tests can leak into mailbox.
Fix: Pin-match on unique identifier to filter.
Two-part pattern:
1. Filter at source — only forward events matching test's identifier
2. Pin in assertion — ^variable rejects mismatches that slip through
Applies to telemetry handlers, PubSub, GenStage/Broadway consumers,
any shared message bus.
Triggered by PR #710 flaky test fix in gargoyle.
Every source reference now links to elixir-lang/elixir at commit f4e1b34.
122 hyperlinks across 11 topic files. Added PATTERN_COMPLETE sentinels.
Removed from-source.md (326 lines, shallow) — covered by existing files.
Extracted patterns, conventions, and code smells directly from the
Elixir and Phoenix source code with file path and line number citations.
Covers: GenServer, error handling, data transforms, process design,
testing, documentation, typespecs, macros, behaviours, module organization,
Phoenix-specific patterns, framework deviations, and anti-patterns.
Rodin
aweiker
Aaron Weiker