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)

Ergonomic Mocking for Elixir Unit Testing

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.

Mocks for Elixir functions

Automatically run tests when files change

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.

Run PropEr test suites

A QuickCheck-inspired property-based testing tool for Erlang

Build tool & plugin for generating Cobertura XML reports

Gleam bindings to Erlang's EUnit test framework

Automated contract testing for functions and mocks.

Concurrent feature tests for elixir

Coveralls for Erlang

Low-level WebDriver client for Elixir.

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

Simple mocking library for asynchronous testing.

Execute PhoenixTest cases in an actual browser via Playwright.

Elixir client for the Playwright node.js server.

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

Interactive test runner for mix test with watch mode.

Gherkin file parser for Elixir

Literate test matchers for ExUnit

Show status notifications for ExUnit test runs

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

Make private functions public if Mix.env is :test

Simplify and reduce test clutter when testing Telemetry events

Snapshot testing tool using familiar assertions

Easy local cluster creation to aid in unit testing

Story BDD tool for executing elixir in ExUnit

Lcov test coverage file generator.

Mock third-party services in ExUnit

QuickCheck-inspired property testing with integrated shrinking

Rebar3 plugin converting .coverdata files to codecov compatible JSON

Simple trace-based testing framework

Simple library to test LV components live in isolation

Common Test hooks for more readable logs

🐦‍⬛ Snapshot testing in Gleam

Simple macro for parameterized testing

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

A few sentences (a paragraph) describing the project.

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

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

Automated accessibility testing for Elixir web applications using axe-core

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.

Mutation testing plugin for rebar3

Better output for eunit suites

BDD testing framework for Elixir inspired by RSpec.

Webdriver library for integration testing and browser automation

Tool for mocking in tests

A testing utility for running snapshot tests

Official Buildkite Test Analytics Collector

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.

Functions to wait for some condition in tests

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.

Concurrent mocks for gRPC Elixir

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.

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.

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.

Triq (Term Reductive Invariant Questant) QuickCheck

A library for creating test simulators for external services.

A library to declaratively write testable effects for asynchronous testing

ExUnit assert helpers for testing rendered HTML.

Simulate remote HTTP services with local Bandit servers.

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

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

A mocking library particularly suitable for stateful property based testing.

Test factories for Ash resources.

Pretty EUnit test formatters

Cucumber for Elixir: BDD testing framework with Gherkin syntax

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.

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

ESpec for Phoenix web framework.

A thin Elixir wrapper around the Erlang snabbkaffe trace-based testing library.

Real-time Buildkite annotations for ExUnit test failures

Generate a generic test execution file for SonarQube

Publicist allows developers to test private (defp) functions

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

Covertool Build Plugin for Cobertura XML reports

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

Registry to help create sandboxes for testing

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

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

Dummy package to test release automation scripts

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

Isolate your tests from the world with Walkman

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

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

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.

TestParrot helps in stubbing unit tests for pure functions

Elixir implementation of the cucumber messages protobuf schema

Fake Membrane sinks that drop incoming data

ExUnit.CaptureLog with custom formatter

BDD-like syntax for ExUnit

https://github.com/edgurgel/httparrot

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

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

Power Assert in Elixir. Shows evaluation results each expression.

ResponseSnapshot is a testing tool for Elixir that captures the output of responses and ensures that they do not change in between test runs.

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

Implementation delegation without boilerplate

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

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

Common Tests Group Summary Hook

Opinionated library for testing timer-based Elixir code

A Testing Framework for LFE

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

Addons for eunit

A stateful mock Stripe server for testing Elixir applications

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