OneBusAway / watchdog / 39128930209

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main: 76%

Pull #189

github

fix(metrics): deduplicate unmatched stop IDs when computing unresolved metric

When OneBusAway's /api/where/metrics.json endpoint reports unmatched stop IDs for an agency, entry.StopIDsUnmatched[agencyID] can contain duplicate stop IDs if multiple vehicles or trip updates encounter the same unmatched stop in an update cycle.

gtfs.GetStopLocationsByIDs indexes stops into a map keyed by stop ID, resolving each unique stop at most once. Previously, fetchObaAPIMetrics counted resolved stops from the returned map and calculated unresolved := len(unmatchedStopIDs) - resolved. When duplicate stop IDs were present, len(unmatchedStopIDs) was greater than the number of unique stops, causing unresolved > 0 even when all unique stops were successfully resolved against the GTFS bundle.

This resulted in false-positive oba_unmatched_stop_unresolved gauge metrics and false warning logs ("OBA unmatched stop IDs could not be resolved against the local GTFS bundle").

Deduplicate unmatchedStopIDs into unique IDs before resolving and computing the unresolved count. Add a unit test to verify duplicate unmatched stop IDs do not produce a non-zero unresolved metric.

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