Testing

Coverage report tool for Elixir with coveralls.io integration.

Mocks and explicit contracts for Elixir

A mocking framework for Erlang

Data generation and property-based testing for Elixir

An ExUnit.Formatter that produces an XML report of the tests run in the project _build dir. It is a good fit with Jenkins test reporting plugin, for example.

A factory library by the creators of FactoryBot (née FactoryGirl)

A mocking library for the Elixir language. We use the Erlang meck library to provide module mocking functionality for Elixir. It uses macros in Elixir to expose the functionality in a convenient manner for integrating in Elixir tests.

Automatically run tests when files change

Mocks for Elixir functions

Bypass provides a quick way to create a custom plug that can be put in place instead of an actual HTTP server to return prebaked responses to client requests. This is helpful when you want to create a mock HTTP server and test how your HTTP client handles different types of server responses.

Ergonomic Mocking for Elixir Unit Testing

Build tool & plugin for generating Cobertura XML reports

Automated contract testing for functions and mocks.

Run PropEr test suites

A QuickCheck-inspired property-based testing tool for Erlang

Gleam bindings to Erlang's EUnit test framework

Coveralls for Erlang

Concurrent feature tests for elixir

Simple mocking library for asynchronous testing.

Low-level WebDriver client for Elixir.

HTTP request/response recording library for elixir, inspired by VCR.

Execute PhoenixTest cases in an actual browser via Playwright.

Helpful functions with great error messages to help you write better tests.

Elixir client for the Playwright node.js server.

Interactive test runner for mix test with watch mode.

Make private functions public if Mix.env is :test

Show status notifications for ExUnit test runs

Gherkin file parser for Elixir

Literate test matchers for ExUnit

Simplify and reduce test clutter when testing Telemetry events

Easy local cluster creation to aid in unit testing

Simple library to test LV components live in isolation

Mock third-party services in ExUnit

Lcov test coverage file generator.

Snapshot testing tool using familiar assertions

Story BDD tool for executing elixir in ExUnit

ExUnit's assert on steroids that writes and updates tests for you

Common Test hooks for more readable logs

PropCheck provides property based testing and is an Elixir layer around PropEr. It is also inspired by Quviq's QuickCheck Elixir library.

Simple trace-based testing framework

Rebar3 plugin converting .coverdata files to codecov compatible JSON

Simple macro for parameterized testing

Better output for eunit suites

Webdriver library for integration testing and browser automation

A few sentences (a paragraph) describing the project.

🐦‍⬛ Snapshot testing in Gleam

BDD testing framework for Elixir inspired by RSpec.

Automated accessibility testing for Elixir web applications using axe-core

Mutation testing plugin for rebar3

With FakeServer you can create individual HTTP servers for each test case, allowing external requests to be tested without the need for mocks.

Wormwood is a tiny library to aid in testing GraphQL queries against an Absinthe schema. It allows you to test your query documents inside ExUnit test modules, and requires no HTTP requests to occur during testing.

Double is a simple library to help build injectable dependencies for your tests. It does NOT override behavior of existing modules or functions.

A testing utility for running snapshot tests

QuickCheck-inspired property testing with integrated shrinking

Official Buildkite Test Analytics Collector

Testcontainers is an Elixir library that supports ExUnit tests, providing lightweight, throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.

Playwright is an Elixir library to automate Chromium, Firefox and WebKit browsers with a single API. Playwright delivers automation that is ever-green, capable, reliable and fast.

Functions to wait for some condition in tests

A utility for defining eminently readable parameterized (or example-based) tests in ExUnit

ArchUnit-inspired architecture testing library for Elixir. Write ExUnit tests that enforce dependency rules, layered architecture, modulith bounded contexts, and naming conventions.

A library to declaratively write testable effects for asynchronous testing

ExUnit assert helpers for testing rendered HTML.

Triq (Term Reductive Invariant Questant) QuickCheck

Concurrent mocks for gRPC Elixir

Tool for mocking in tests

A utility module that helps you iterate faster on unit tests. This module lets execute specific tests from within a running iex shell to avoid needing to start and stop the whole application every time.

Pretty EUnit test formatters

GrpcMock is mocking library for [Elixir gRPC implementation](https://github.com/tony612/grpc-elixir). It provides seamless mock creation based on `pb.ex` definition and usual mocking "expect" - "verify" mechanisms.

Language-agnostic mutation testing library for Elixir, Erlang, and other BEAM languages. Evaluates test suite quality by introducing deliberate bugs into code and verifying that tests catch them. Intelligent file filtering, 6 mutation strategies, parallel execution, multiple output formats.

The library outputs test results to the console, which helps speed up the red-green test correction cycle (inspired by rspec)

Generate a generic test execution file for SonarQube

A mocking library particularly suitable for stateful property based testing.

A mix task to run eunit tests, works for umbrella projects

ESpec for Phoenix web framework.

Lightweight server-side integration test functions for Phoenix. Optimized for Elixir Pipes and the existing Phoenix.ConnTest framework to emphasize both speed and readability.

Real-time Buildkite annotations for ExUnit test failures

Test factories for Ash resources.

Simulate remote HTTP services with local Bandit servers.

A convenience library to spawn plug router with your application for testing purposes

Spin up dynamic clusters in ExUnit tests with no special setup necessary.

Registry to help create sandboxes for testing

Macros to support assertions/refutations that might not be correct immediately but will eventually become so due to, say, eventual consistency.

Isolate your tests from the world with Walkman

Covertool Build Plugin for Cobertura XML reports

HTMLTestHelpers provides function helpers for unit testing allowing easy assertions for HTML elements data queried by data-testid attribute.

A collection of goodies for the property-based testing framework PropEr

TestParrot helps in stubbing unit tests for pure functions

Dummy package to test release automation scripts

A simplified method for configuring modules to be mockable with Mox in Elixir projects.

Cucumber for Elixir: BDD testing framework with Gherkin syntax

Publicist allows developers to test private (defp) functions

Builds on the Mox pattern — generates behaviours and dispatch facades from `defcallback` declarations — and adds stateful test doubles powerful enough to test Ecto.Repo operations without a database.

ExUnit.CaptureLog with custom formatter

Elixir implementation of the cucumber messages protobuf schema

BDD-like syntax for ExUnit

A simple property-based testing framework written in pure Elixir.

Power Assert in Elixir. Shows evaluation results each expression.

Tapex is a TAP (Test Anything Protocol) formatter for ExUnit.

Zero-dependency Elixir coverage tool built for AI-assisted development

Implementation delegation without boilerplate

https://github.com/edgurgel/httparrot

Common Tests Group Summary Hook

Stubr is a set of functions helping people to create stubs and spies in Elixir.

AI-friendly JSON test output for ExUnit. Provides structured JSON output from mix test for use with AI editors like Claude Code.

Opinionated library for testing timer-based Elixir code

Test your package against different versions of its dependencies

Fake Membrane sinks that drop incoming data

A wrapper for tracing test runs using TTB

A Testing Framework for LFE

A mocking library for ExUnit inspired by RSpec and based on meck.

A library that contains test utilites used in the Smart City project

Addons for eunit

Elixir Gherkin parser.

A fresh approach to testing

An Elixir mock HTTP(S) server useful for testing HTTP(S) clients.