Rendered from docs/obligations/0132-survey-the-wiring-decisions-of-main-rs-verb-by-verb-and-cover-the-quiet-ones.md in the Headwater corpus. Every document on this half of the site is typed by the taxonomy the descriptor names: corpus.json.

Survey the wiring decisions of main.rs, verb by verb, and cover the quiet ones

Context

engine/crates/cli/tests/wiring.rs holds one case each for check --change, probe grade, and the Loaded::runs() call site that feeds generate, from #179. Each case was watched failing against the pre-fix form of a defect a person found only by reading the code after something else broke. None of the three defects moved an exit code, so nothing before that reading would have reported them.

A wiring decision is a place where main.rs chooses which library value to trust, rather than a place where a library computes one. The three fixes already made took three shapes. One read a rule at the wrong grain. One parsed an input and did not inject it where it needed to reach. One composed a value and handed it on with part of it dropped. main.rs runs to about 3,700 lines across thirty verbs, and nothing has enumerated where else it makes a decision of this shape.

Two further sites are already named. probe stale is the third caller of Plan::gradable(), and it is the one caller not already covered by type or by test. The taxonomy vendor doctrine report, added by #81 after this issue was filed, makes two wiring decisions of its own. It re-derives flattened from record.package where package::vendor derives it from identity. That is safe only because identity refuses a record whose header disagrees with the manifest. It also reads the installed manifest with manifest_at(&installed).ok(), so a read error prints nothing at all. Both decisions were confirmed by hand and by nothing else, during construction and again during verification.

Obligation

The corpus owes a survey of main.rs, verb by verb, that records every wiring decision as covered, structurally impossible, or uncovered. A verb that decides nothing is recorded as making none.

Every uncovered decision with a quiet failure, one that moves no exit code, owes a case in crates/cli/tests/wiring.rs. Each case is watched failing against the form its defect names.

Where a decision can be made unwritable instead of merely tested, it owes that treatment first. Plan::gradable() and Unbound::bind are the two idioms already in the tree. A structural guarantee replaces a case that has to remember to run.

probe stale owes coverage now, as the third caller of Plan::gradable(). Its symptom would be a read set composed over part of a selection a planner abandoned before finishing.

The taxonomy vendor doctrine report owes two cases of its own. One covers the flattened path, re-derived from record.package instead of from identity. The other covers the silent read of the installed manifest through manifest_at(&installed).ok(), which reports nothing on failure.

The remaining twenty-seven verbs owe the survey itself, and the survey owes a stated cost rather than a discovered one. The existing target runs in 0.05 seconds under cargo test, and a spawned case costs about 15 milliseconds. A survey that produces thirty such cases should report that cost rather than discover it.

Discharge

This is discharged when the survey exists as a table over all thirty verbs. Each row names a verb as covered, structurally impossible, or uncovered, and no verb is left unlisted.

It is discharged further when every uncovered decision whose failure is quiet has a case in crates/cli/tests/wiring.rs, each one watched failing first.

Where a decision can be made structurally impossible instead of tested, that treatment discharges it in place of a case. Plan::gradable() and Unbound::bind set that pattern already.

The two named sites, probe stale and the taxonomy vendor doctrine report, discharge on the same terms once their cases exist and pass.

This waits on an adopter to run the survey, choose the treatment for each finding, and add the resulting cases without adding a new gate.