Control CLI
Exercise an interactive terminal program through a small, repeatable harness. Prefer a repository-native demo or test harness; only assemble a temporary PTY or terminal session when the project has no suitable one.
Harness Loop
- Identify the command, smallest fixture, expected ready marker, and cleanup condition.
- Discover existing package scripts, PTY helpers, expect scripts, demo recorders, or TUI tests.
- Launch in an isolated environment with deterministic variables and local disposable data.
- Capture the initial screen or transcript.
- Send one action at a time and wait for a concrete prompt or screen marker.
- Capture the resulting transcript and any requested profile artifact.
- Stop the process and remove temporary sessions, ports, and profiles.
On Windows, prefer the project's own test runner or a checked-in Python/Node
probe. Use ConPTY or an already-installed PTY helper when available; do not add
a dependency just to run a one-off probe. On other systems, tmux, pty, or a
repository-supported terminal harness may be appropriate.
Evidence
For a bug fix or regression, run the same deterministic interaction against the
baseline and treatment and pass the captures to verify-this. For a hang, keep
the last screen, process exit state, timeout, and a stack/CPU sample when
available. For memory growth, use equal repetitions and record before/after
snapshots or a bounded allocation metric.
Prefer stable text markers and accessibility-aware terminal probes over sleeps. If a sleep is unavoidable, state why and keep it bounded.
Safety
- Never send credentials, destructive commands, or production paths into the controlled session.
- Do not rely on stale screen state after navigation, resize, or a prompt change.
- Do not hard-code paths, ports, or commands from another repository.
- Keep transcripts and profiles private when they contain prompts, source, or user data.
Gotchas
- A process that exits successfully before receiving input is not proof that the interactive flow works; assert the ready marker and the expected state change.
- Fixed sleeps hide race conditions and make a green run non-repeatable.
- A terminal transcript can miss rendering defects; use a real UI surface for graphical claims.
- Cleanup must be verified, especially after a timeout or forced interrupt.
Troubleshooting
| Symptom | Likely cause | Action |
|---|---|---|
| Harness hangs | Wrong ready marker or child process owns the terminal | Capture the screen, inspect the process tree, then terminate cleanly |
| Input is ignored | Program is not in the expected prompt state | Wait for a fresh marker and send one action only |
| Works manually, fails in harness | Hidden environment, terminal size, or timing dependency | Record env/size and replace sleeps with state-based waits |
| Transcript is empty | Output is on another stream or the PTY was detached | Capture stdout and stderr through the repo-native harness and verify file size |
Source
Adapted from Cursor Team Kit's MIT-licensed control-cli workflow:
https://github.com/cursor/plugins/tree/main/cursor-team-kit/skills/control-cli
