# mesh-delivery-gate

The `mesh-delivery-gate` module of the mesh catalogue: the gate of design 47. It claims the seat `mesh-delivery`, whose
name stays (ADR 0437 §11), and takes over from the module `mesh-delivery` (ADR 0437 §3, ADR 0450 §6). Its buckets are
`mesh-delivery-gate_*`.

## Files it does not know

Each directory or archive this module declares says how it treats a file it did not write (ADR 0422, ADR 0416).

- `${dir:state}`: everything in it is the program's; the mesh moves nothing out (ADR 0422 §2).

## What it keeps (ADR 0539 §17)

The gate keeps the merge's states: proposed, ready, rejected, merged, held (a merge that reached the trunk without a passing
check) and closed. It asks the operator's Approve and merges once, moving `source.main`. It asks the controller nothing, follows
no plan event and derives nothing after the merge: whether a merged change reached the machines is the view's, from
`source.main`, the wants and the haves. The seat `mesh-delivery` keeps the verbs `deliveries`, `show`, `groups`, `checks`,
`table`, `stalled` (for a merge or a check past its bound), `recheck` and `close`; `times`, `what-if`, `release`, `stop` and
`retire-history` went with the plans, so the gate stays a bundle serving the seat. A delivery an earlier owner kept in a state that
is gone is read as the state it came to (merged, closed or proposed) when the gate starts.

## When a refused or rejected merge is said (ADR 0505 §4, §5)

`stalled` is what the controller raises as a condition for the operator. The gate's own list (`show`, `deliveries`)
names every refusal and rejection at once, and the pull request is told at once; only `stalled` waits:

- a merge refused because its trunk moved, whose check the gate asked again, is stalled only once that check answered and
  the merge was refused again, or twice the repository's last check time passed (at least the setting
  `refusal-stall-floor-minutes`, 10). Every other refusal is stalled at once.
- a delivery that needs its author's new head (its check failed after its Approve: a conflict, a failed check, a rejected
  group) is stalled only once no new head came for the setting `author-new-head-minutes` (120). Its line says
  `needs: new-head` and names its author: the branch, and the session a `Pushed-by: <who@node>` line in the pull
  request's description names.

## The seat's hand-over

The gate took the seat `mesh-delivery` over from the module `mesh-delivery` (ADR 0449 §4, ADR 0450 §6, ADR 0454) and carried its
deliveries, groups and pull keys once; the carry, and the reading of the controller's assignments and the node-engine's have keys
that waited for it, went with release 6. `catalogue_test.go` keeps the catalogue to one claimant of the seat.