The SAS-runtime poll loop in processProgram only checked for
SessionState.completed, so a session that failed (e.g. via %abort;)
left the loop spinning on delay(50) forever - the request never
resolved, even though the SAS log had already been written. Split a single completed-on-either-outcome
flag into separate completed/failed states without updating this loop.
- processProgram now throws when session.state becomes 'failed'
- Execution.ts catches that, reads the complete log (guaranteed
complete since the session's process has already exited by then),
and throws a SessionExecutionError carrying it
- stp.ts/code.ts surface { ..., log } in the HTTP error response
- add unit tests for the poll loop and the log-enrichment logic, plus
a mock SAS executable + end-to-end test exercising the real
session/process pipeline without needing a SAS install
- add docs/diagrams covering the session lifecycle and the SAS
execution handshake mechanism, for future context
YuryShkoda