Silent error swallowing in Enqueue/Len/Values/Purge/Close hides failures

[fahimfaisaal]

Summary

Several operations swallow errors and return zero-values, so callers cannot distinguish "empty/failed silently" from success. Grouping the low-severity cases here.

Details

a. Enqueue accepts any into a BLOB NOT NULL with no type guard

queue.go:90-115 / priority_queue.go:61-91. item any is passed straight to the driver. Anything that is not []byte/string/numeric fails at the driver and Enqueue returns false with no explanation. The []byte contract is implicit.
Fix: document that item must be []byte (the adapter's contract), or assert/convert and return a typed error.

b. Read/maintenance methods discard errors

• Len() queue.go:255-263 returns 0 on any error — an errored query looks like an empty queue.
• Values() queue.go:266-286 returns nil on query error and silently continues on scan error.
• Purge() queue.go:289-306 and Close() return nothing / drop errors.

Fix: return errors (or at minimum log them) so a failed query is not indistinguishable from an empty queue. If the varmq interface fixes these signatures, add internal logging behind the no-error facade.

Impact

Low individually, but collectively they make failures invisible and debugging hard.

Possible fix

Introduce error-returning internal variants and surface via logging where the public interface cannot change, and tighten the Enqueue contract/documentation.