rescript-vitest

ReScript bindings to Vitest

Prerequisite

ReScript v10.1+ is required since v1.0.0. To use Js.Promise2 and async/await for tests.

ReScript v11.x with the uncurried mode is supported since v2.x.

Config

Configure with plain vite.config.js or vitest.config.js.

You can use vite-plugin-rescript to build ReScript automatically before the test.

Note

You may need to exclude lib/bs directory manually, otherwise some build artifacts can be picked by Vitest and fail. See #36 for details.

Example config:

// vitest.config.js
import { configDefaults, defineConfig } from 'vitest/config';
import rescript from 'vite-plugin-rescript';

export default defineConfig({
  test: {
    exclude: [
      ...configDefaults.exclude, 
      'lib/bs/**',
    ],
  },
  plugins: [
    rescript(),
  ],
});

Usage

You can find examples on tests

Basic

open Vitest

describe("Hello, Vitest", () => {
  test("This is a test case", t => {
    // t is `expect` object for suite-wide assertions
    t->assertions(3)

    // Test using the `Expect` module
    t->expect(1 + 2)->Expect.toBe(3)

    // There are some nested modules for specific type
    t->expect([1, 2, 3])
    ->Expect.Array.toContain(2)

    t->expect("Hello, ReScript-Vitest!")
    ->Expect.String.toContain("ReScript")

  // You can specify timeout for a test suite
  }, ~timeout=2000)
})

In-source testing (experimental)

Vitest support in-source testing

// This if block can be removed from production code.
// You need to define `import.meta.vitest` to `undefined`
if Vitest.inSource {
  open Vitest.InSource

  test("In-source testing", t => {
    t->expect(1 + 2)->Expect.toBe(3)
  })
}

LICENCE

MIT