# `Runic.Runner.Scheduler.ContractTest`
[🔗](https://github.com/zblanco/runic/blob/main/lib/runic/runner/scheduler/contract_test.ex#L1)

Conformance test suite for `Runic.Runner.Scheduler` behaviour implementations.

Verifies that a scheduler correctly implements the dispatch contract:

  * `init/1` returns `{:ok, state}`
  * `plan_dispatch/3` returns well-formed dispatch units
  * All input runnables are accounted for (no dropped runnables)
  * No duplicate runnables across dispatch units
  * No overlapping `node_hashes` between dispatch units
  * Promise `node_hashes` are supersets of their runnable hashes
  * Empty input produces empty output
  * State is properly threaded across calls

## Usage

    defmodule MySchedulerTest do
      use Runic.Runner.Scheduler.ContractTest,
        scheduler: MyApp.CustomScheduler,
        opts: [my_option: true]
    end

---

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