Engine Test Suite Rebuild 2026 07 04

Engine Test Suite Rebuild — 2026-07-04

QA Strategies · Troubleshooting and Error Codes · Command Reference

What happened

The coverage tables in QA Strategies (§Testing the orchestrator itself) referenced an engine/CLI test suite — test_exit_codes.py, test_log_buffer.py, test_executor.py, test_orchestrator_lifecycle.py, test_run_exit_codes.py, test_run_flags.py, test_run_archive.py, test_run_ci_ndjson.py, test_config_discovery.py, test_cli_commands_smoke.py, test_exit_code_contract.py, test_subprocess_smoke.py — that did not exist anywhere under tests/.

An audit found __pycache__ remnants (compiled under pytest 9 / CPython 3.12–3.13) in tests/fixtures/engine/, tests/unit/testo_core/engine/, tests/unit/testo_core/cli/, and tests/integration/testo_core/engine/, but zero git history for any of those paths. The suite was written and executed in a working tree that was wiped before the files were ever committed. Only tests/unit/testo_core/engine/test_orchestrator.py (fail-fast lifecycle, commit afead659) survived.

What was rebuilt

All twelve files above plus the tests/fixtures/engine/ package (EchoAdapter / HangAdapter / MissingBinaryAdapter, NoopRenderer, YAML builders, NDJSON helpers, scripts/echo.py + scripts/hang.py). Stages in the CLI tests run as real subprocesses (echo.py stands in for pytest/behave), driven through Typer's CliRunner; the whole suite (~110 tests) runs in about 4 seconds. See the updated coverage matrix in QA Strategies for the row-by-row mapping; rows for unimplemented CLI flags (--tag, --fail-fast, --dry-run, --reporter) and archive exit-code escalation (EC-03c–e, EC-06, CLI-10) are now explicitly labelled Gap (roadmap).

Engine contract fixes restored alongside

Writing the tests exposed two places where the engine had drifted from the documented exit-code contract in Troubleshooting and Error Codes:

1. Stage timeouts — executor.run_stage recorded the raw signal returncode (e.g. -15 after SIGTERM), so timeouts classified as exit 1 instead of the documented 3. The executor now normalises timeouts to returncode=124 (timed_out=true unchanged).
2. Internal failures — classify_exit_code had no internal_failure parameter, so an orchestrator-caught engine exception (synthetic stage returncode=4) classified as a domain failure (exit 1). StageResult gained an internal_failure: bool field, the orchestrator sets it on the defensive path and passes the flag to the classifier, and the artifact events.ndjson stage_finished mirror now includes it. Exit 4 is therefore reachable as documented (EC-04), while a framework genuinely returning 4 still classifies as exit 1 (EC-07).

Both fixes are locked by tests/contract/testo_core/test_exit_code_contract.py.

Lessons learned

• Uncommitted work does not exist. The suite was fully written, green, and referenced from the vault — and still vanished. Commit and push incrementally (the repo rule is every change goes to origin).
• Docs written against uncommitted code become silent fiction. The coverage matrix now labels unimplemented surface as Gap (roadmap) instead of naming files, so a future audit can distinguish "planned" from "lost".

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