# Credo [](https://travis-ci.org/rrrene/credo) [](https://inch-ci.org/github/rrrene/credo)
Credo is a static code analysis tool for the Elixir language with a focus on teaching and code consistency.
## What can it do?
`credo` can show you refactoring opportunities in your code, complex code fragments, warn you about common mistakes, show inconsistencies in your naming scheme and - if needed - help you enforce a desired coding style.
## Installation and Usage
The easiest way to add Credo to your project is by [using Mix](http://elixir-lang.org/getting-started/mix-otp/introduction-to-mix.html).
Add `:credo` as a dependency to your project's `mix.exs`:
```elixir
defp deps do
[
{:credo, "~> 1.2", only: [:dev, :test], runtime: false}
]
end
```
And run:
$ mix deps.get
$ mix credo
## Issues
Like any code linter, Credo reports issues. Contrary to many other linters these issues are not created equal. Each issue is assigned a priority, based on a base priority set by the config and a dynamic component based on violation severity and location in the source code.
These priorities hint at the importance of each issue and are displayed in the command-line interface using arrows: ↑ ↗ → ↘ ↓
By default, only issues with a positive priority are part of the report (↑ ↗ →).
## Checks
### Consistency
These checks take a look at your code and ensure a consistent coding style. Using tabs or spaces? Both is fine, just don't mix them or Credo will tell you.
### Readability
Readability checks do not concern themselves with the technical correctness of your code, but how easy it is to digest.
### Refactoring Opportunities
The Refactor checks show you opportunities to avoid future problems and technical debt.
### Software Design
While refactor checks show you possible problems, these checks try to highlight possibilities, like - potentially intended - duplicated code or `TODO:` and `FIXME` annotations.
### Warnings
These checks warn you about things that are potentially dangerous, like a missed call to `IEx.pry` or a call to `String.downcase` without saving the result.
## Plugins
## Integrations
### IDE/Editor
Some IDEs and editors are able to run Credo in the background and mark issues inline.
* [IntelliJ Elixir](https://github.com/KronicDeth/intellij-elixir#credo) - Elixir plugin for JetBrains IDEs (IntelliJ IDEA, Rubymine, PHPStorm, PyCharm, etc)
* [linter-elixir-credo](https://atom.io/packages/linter-elixir-credo) - Package for Atom editor (by @smeevil)
* [ElixirLinter](https://marketplace.visualstudio.com/items?itemName=iampeterbanjo.elixirlinter) - VSCode plugin (by @iampeterbanjo)
### Automated Code Review
* [Codacy](https://www.codacy.com/) - checks your code from style to security, duplication, complexity, and also integrates with coverage.
* [SourceLevel](https://sourcelevel.io/) - tracks how your code changes over time and have this information accessible to your whole team.
* [Stickler CI](https://stickler-ci.com/) - checks your code for style and best practices across your entire stack.
## Contributing
1. [Fork it!](http://github.com/rrrene/credo/fork)
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create new Pull Request
## Author
René Föhring (@rrrene)
## License
Credo is released under the MIT License. See the LICENSE file for further
details.
