# `Trellis.SelfCheckReport`
[🔗](https://github.com/salesforce-misc/trellis/blob/v0.1.0-alpha/clients/elixir/lib/trellis/self_check.ex#L57)

What a finished `Trellis.self_check/3` job found auditing the whole of a
target table against a fresh recompute of its definition from the source.

- `outcome` is `:converged` (every compared cell, row and column matched),
  `:not_caught_up` (the target didn't catch up within `:timeout_ms`; not a
  verdict on correctness), `:not_live` (the transform isn't `:live`, so
  nothing was awaited or compared; see `status`), or `:diverged` (see
  `divergences`).
- `status` is the transform's status when `outcome` is `:not_live` (a
  rebuild `Trellis.request_backfill/2` starts reads `:backfilling` from the
  call's return, so poll the status until it is `:live`, then check
  again), and `nil` for every other outcome.
- `divergences` lists what differed; it is `[]` unless `outcome` is
  `:diverged`.
- `rows_compared` counts the distinct keys compared.
- `truncated` is `true` when the job stopped before the end of the
  target's keys: it found 1,000 divergences, or the transform stopped
  being `:live`, stopped catching up or lost its capture partway.
  `rows_compared` says how far it got.
- `checked_through` is the watermark the outcome holds through, a token
  `Trellis.await_converged/3` takes.
- `held_keys` is set, whatever the outcome, while the transform holds keys
  in quarantine (see `Trellis.HeldKeys`), read when the job is polled:
  their target rows are ones the audit can't vouch for, and a key with
  held changes keeps the target from catching up, so the outcome is
  `:not_caught_up` until it is released.
- `drain_failures` lists, whatever the outcome, every page the drain keeps
  failing on with nothing charged or paused (see `Trellis.DrainFailure`),
  oldest first, whichever transforms read its tables, read when the job is
  polled; `[]` when there is none. Each holds back the targets of the
  tables it holds changes to, and with them the convergence the audit
  waits on.

# `outcome`

```elixir
@type outcome() :: :converged | :not_caught_up | :not_live | :diverged
```

The verdict of a `Trellis.self_check/3` job.

# `t`

```elixir
@type t() :: %Trellis.SelfCheckReport{
  checked_through: Trellis.watermark(),
  divergences: [Trellis.Divergence.t()],
  drain_failures: [Trellis.DrainFailure.t()],
  held_keys: Trellis.HeldKeys.t() | nil,
  outcome: outcome(),
  rows_compared: non_neg_integer(),
  status: Trellis.Status.status() | nil,
  target: String.t(),
  truncated: boolean()
}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*