A testing framework for writing unit and fuzz tests in Elm, enabling property-based testing with random inputs.
elm-test is a testing framework for the Elm programming language that allows developers to write unit and fuzz tests for their code. It provides functions to define test suites, run tests with random inputs, and assert expectations, helping ensure Elm applications are robust and bug-free. The framework integrates with Elm's type system to encourage writing tests that catch edge cases early.
Elm developers building applications or libraries who need a reliable way to test their code, especially those interested in property-based testing and maintaining high code quality.
Developers choose elm-test because it's the standard testing solution for Elm, offering both unit and fuzz testing in a type-safe environment. Its seamless integration with Elm's ecosystem and focus on random input generation make it uniquely effective for catching hard-to-find bugs.
Write unit and fuzz tests for Elm code.
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Built-in fuzz function runs tests hundreds of times with randomly generated inputs, catching edge cases that unit tests might miss, as demonstrated in the README's string reversal example.
Encourages tests that align with Elm's type system to make impossible states unrepresentable, reducing bug surface area and promoting reliable code.
Uses describe blocks to organize tests hierarchically, improving readability and maintainability, as shown in the example suite structure.
Provides skip, only, and todo functions to manage test focus during development, with safeguards that treat incomplete runs as failures in CI to prevent accidents.
Includes Test.Html modules for testing views and event handling in web applications, essential for frontend Elm development, as mentioned in the README.
The README explicitly admits there is no Elm solution for integration or end-to-end testing, forcing reliance on external tools like Cypress or Capybara.
Requires separate CLI tools like node-test-runner or elm-test-rs to execute tests, adding setup complexity compared to all-in-one testing frameworks.
Only usable for Elm code, making it unsuitable for projects with mixed technology stacks or those needing unified testing across languages.
Elm's pure functional nature complicates mocking dependencies for side effects, which can hinder testing of code interacting with external systems.