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.
Pattern 10 (Callback Documentation Convention) now owns the full rule
for callback documentation — both the behaviour side (@callback docs)
and the implementation side (when to override @doc false on @impl
functions). Patterns 2 and 5 cross-reference Pattern 10 instead of
making their own partial statements.
The test: "Would this statement be true of any implementation?" If yes,
it belongs on the @callback. If no, the implementation earns its own
@doc.
Adds 5 new pattern files covering the core Ecto APIs, each with real
source citations at commit fd2ec52b, before/after examples, anti-patterns,
and decision trees.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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.
Using codebase-analysis skill (patterns mode) on the language source.
Real examples from the repo, not invented. Each pattern has:
- Rule, Example, Why, When NOT to use, Source file.
Topics: module org, protocol design, error handling, testing,
documentation, naming, process design, smells.
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