Intentional Error Handling

Handle errors based on intent: make operations idempotent for known conflicts, and explicitly classify/propagate errors for known transient conditions.

Apply this standard in test scripts and helper utilities:

• For deterministic conflicts (e.g., resource already exists), use the command’s recovery flag rather than letting the call fail.
• For remote/cluster calls, wrap the call in catch, and:
  • Treat known transient routing issues (e.g., MOVED*, ASK*) as recoverable (retry/continue).
  • Re-raise anything else immediately so real bugs don’t get masked.

Example patterns:

# Known conflict: make restore idempotent
catch {r restore key 0 $crafted replace} err

# Known transient cluster routing: ignore MOVED/ASK, fail fast otherwise
if {$cluster_load == 1} {
    if {[catch {$r read} err]} {
        if {[string match {MOVED*} $err] || [string match {ASK*} $err]} {
            continue
        }
        error $err
    }
} else {
    $r read
}