@reventlessdev/rescript-jest
Alpha. APIs and on-disk formats can change without notice between releases. Pin exact versions and expect breaking changes.
Direct ReScript bindings to Jest's global APIs, with throwing expect and
native async test bodies.
This is the single, shared replacement for the per-package Jest binding modules
the monorepo used to hand-roll (AsyncTest, TestHelpers, JestBind). ReScript
module visibility is per-package, so each package that needed async-capable,
throwing-expect bindings re-wrote them; this package consolidates that surface
at the bottom of the dependency graph.
Why not @glennsl/rescript-jest?
glennsl's assertion model is deferred by design: expect |> toBe builds a value
that only executes when it is returned from the test body (one affirmed
assertion per test). A mid-test assertion whose result is not returned is
silently inert — a forgotten return passes green. Its testPromise also
discards the returned Promise, so async tests in a describe block race.
These bindings call Jest's globals directly: every expect(...)->toBe(...)
executes at its line, and async () => ... test bodies are awaited.
Usage
open JestGlobals
describe("widget", () => {
testSync("adds", () => {
expect(1 + 1)->toBe(2)
})
test("loads async", async () => {
let v = await fetchValue()
expect(v)->toEqual(expected)
})
})test registers an async test; testSync a synchronous one. beforeAll /
afterAll are synchronous; beforeAllAsync / afterAllAsync await a returned
promise. Matchers are available both flat and under module Expect.
Links
- Documentation — docs.reventless.dev
- Repository — ReventlessDev/reventless-core
- Changelog