snowplow / snowplow-golang-tracker / 22676918636

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master: 94%

Pull #91

github

Fix race conditions in Emitter for concurrent usage (Close #90)

PR #89
* test: enable race detection in test suite
Enables Go's race detector (-race flag) when running tests to detect
data races in concurrent code. Also switches coverage mode to 'atomic'
which is required when using race detection.

This change exposes existing race conditions in the emitter implementation
that occur during concurrent use of the tracker.

* fix: add mutex protection to eliminate race conditions in Emitter

Fixes multiple race conditions that occur when Emitter is used concurrently:

1. SendChannel race: Added sync.Mutex to protect SendChannel access in
   start() and Stop(). The check-then-create pattern was causing races
   when multiple goroutines called these methods simultaneously.

2. Configuration field races: Added sync.RWMutex to protect concurrent
   access to configuration fields (CollectorUrl, RequestType, ByteLimitGet,
   ByteLimitPost). The doSend() method now reads these fields under lock
   before processing events, and all setter methods use proper locking.

3. Test cleanup races: Added Emitter.Stop() calls in tests that use
   httpmock to ensure all emitter goroutines complete before mock cleanup,
   preventing races in test infrastructure.

The Emitter can now be safely used from multiple goroutines without
data races. All changes maintain backward compatibility with the existing API.

* fix: race edge case in Stop()

If "start" is called while we wait for the lock, we would get an orphaned channel

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Co-authored-by: João Pereira <jpereira@gitlab.com>

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