Introduction

Welcome to your guide on testing Effect-based applications using bun:test and the @domir/bun-test package. This package simplifies running tests for Effect-based code with Bun test.

In this guide, we'll walk you through setting up the necessary dependencies and provide examples of how to write Effect-based tests using @domir/bun-test.

Requirements

First, ensure you have bun installed (version 1.6.0 or later).

Next, install the @domir/bun-test package, which integrates Effect with Bun test.

bun add -D @domir/bun-test

Overview

The main entry point is the following import:

import { it } from "@domir/bun-test"

This import enhances the standard it function from bun:test with several powerful features, including:

Feature	Description
it.effect	Automatically injects a TestContext (e.g., TestClock) when running a test.
it.live	Runs the test with the live Effect environment.
it.scoped	Allows running an Effect program that requires a Scope.
it.scopedLive	Combines the features of scoped and live, using a live Effect environment that requires a Scope.
it.flakyTest	Facilitates the execution of tests that might occasionally fail.