Packages

@argus/queue

Implementations of the Queue contract from @argus/shared. The contract encodes the one ordering rule the product depends on: jobs for the same PR run strictly in order, one at a time; different PRs run in parallel. Without it, a push arriving mid-review could interleave two reviews of one PR — duplicate threads, races on last_reviewed_sha.

Place in the system

The ingress enqueues; the worker consumes. Both depend only on the contract — bin/ wiring picks the implementation via QUEUE_MODE.

The session ordering model

The session key is sessionKeyForJob(job) = org/project/repoId/prId:

flowchart LR
  subgraph q["queue argus-jobs"]
    direction TB
    subgraph s1["session …/PR 41"]
      direction LR
      a1["review.full"] --> a2["review.incremental"] --> a3["thread.reply"]
    end
    subgraph s2["session …/PR 42"]
      b1["review.full"]
    end
  end
  s1 -- "strict FIFO,<br/>one consumer at a time" --> c1["worker replica"]
  s2 -- "in parallel with PR 41" --> c2["worker replica"]

Figure 1 · Sessions in the argus-jobs queue — strict FIFO within a PR, parallelism across PRs.

Poison messages

A handler failure redelivers the job up to 3 times (code default), then dead-letters it without blocking later jobs in the same session — a poison message never wedges its PR.

The two implementations

Implementation	Notes
`MemoryQueue` (`QUEUE_MODE=memory`)	In-process; same FIFO-per-key, bounded-concurrency, dead-letter semantics as production. This is what `dev:ingress` and the tests run on.
`ServiceBusQueue` (`QUEUE_MODE=servicebus`)	Azure Service Bus with sessions. Sends set `sessionId`; consumption is `acceptNextSession` with session-lock auto-renewal for long reviews. Auth: `SERVICEBUS_NAMESPACE` + `DefaultAzureCredential` (primary) or `SERVICEBUS_CONNECTION` (SAS fallback). Dead-letter reasons: `invalid-job` (schema-invalid body) and `max-deliveries-exhausted`.

Sessions are immutable

The Service Bus queue entity must have sessions enabled — the checkbox is immutable after queue creation, and a session-less queue silently breaks consumption.

How it's tested

memoryQueue.test.ts proves the ordering contract (FIFO per key, cross-key parallelism, dead-letter without session blockage); serviceBusQueue.test.ts exercises ServiceBusQueue against a scripted fake of the Service Bus SDK — no Azure needed.

← ingress worker →