# Terminal admission

**Fixture:** `fixture-cli-terminal@1`

## Given

The built `termux-janitor` executable starts with standard input disconnected from a terminal and an
empty isolated working directory. The executable receives no arguments, causing interactive mode
to be attempted.

## When

The executable starts.

## Required invariants

- **`INV-TERM-STATUS`:** The process exits with the failure status (code 1).
- **`INV-TERM-DIAGNOSTIC`:** Standard error contains one concise diagnostic that names the executable,
  states that interactive mode requires a terminal stdin, and repeats the usage summary.

## Forbidden effects

- **`NO-TERM-STDOUT`:** Standard output remains empty.
- **`NO-TERM-FIXTURE-MUTATION`:** The isolated working directory remains empty.

## Instrumentation

```zig tj-test
try fixture.given_program("termux-janitor");
try fixture.given_standard_input(.ignored);
try fixture.given_working_directory(.empty);
try fixture.given_no_arguments();
try fixture.when_run_each();
try fixture.then_inv_term_status();
try fixture.then_inv_term_diagnostic();
try fixture.forbid_no_term_stdout();
try fixture.forbid_no_term_fixture_mutation();
```

## Variations

Running with `TERM=dumb` or with `TERM` unset exercises the TERM‑environment checks. Running
with terminal stdin/stdout present is a separate scenario.

## Limitations

This fixture observes exit status, stderr, and that stdout remains empty. It does not trace
system calls and therefore cannot prove that no other path was read.