Code style linter for Crystal
(a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm)
## About Ameba is a static code analysis tool for the Crystal language. It enforces a consistent [Crystal code style](https://crystal-lang.org/docs/conventions/coding_style.html), also catches code smells and wrong code constructions. See also [Roadmap](https://github.com/veelenga/ameba/wiki). ## Usage Run `ameba` binary within your project directory to catch code issues: ```sh $ ameba Inspecting 107 files. ...............F.....................F.................................................................... src/ameba/formatter/flycheck_formatter.cr:4:33 Lint/UnusedArgument: Unused argument `location` > source.issues.each do |e, location| ^ src/ameba/formatter/base_formatter.cr:12:7 Lint/UselessAssign: Useless assignment to variable `s` > return s += issues.size ^ Finished in 542.64 milliseconds 129 inspected, 2 failures. ``` ## Installation ### As a project dependency: Add this to your application's `shard.yml`: ```yaml development_dependencies: ameba: github: veelenga/ameba version: 0.8.1 ``` Build `bin/ameba` binary within your project directory while running `shards install`. You may also want to use it on [Travis](travis-ci.org): ```yaml # .travis.yml language: crystal install: - shards install script: - crystal spec - bin/ameba ``` Using this config Ameba will inspect files just after the specs run. Travis will also fail the build if some problems detected. ### OS X ```sh $ brew tap veelenga/tap $ brew install ameba ``` ### Docker Build the image: ```sh $ docker build -t ameba/ameba . ``` To use the resulting image on a local source folder, mount the current (or target) directory into `/src`: ```sh $ docker run -v $(pwd):/src ameba/ameba ``` ### From sources ```sh $ git clone https://github.com/veelenga/ameba && cd ameba $ make install ``` ## Configuration Default configuration file is `.ameba.yml`. It allows to configure rule properties, disable specific rules and exclude sources from the rules. Generate new file by running `ameba --gen-config`. ### Only/Except One or more rules, or a one or more group of rules can be included or excluded via command line arguments: ``` $ ameba --only Lint/Syntax # runs only Lint/Syntax rule $ ameba --only Style,Lint # runs only rules from Style and Lint groups $ ameba --except Lint/Syntax # runs all rules except Lint/Syntax $ ameba --except Style,Lint # runs all rules except rules in Style and Lint groups ``` ### Explanation Ameba allows you to dig deeper into an issue, by showing you details about the issue and the reasoning by it being reported. To be convenient, you can just copy-paste the `PATH:line:column` string from the report and paste behind the `ameba` command to check it out. ``` $ ameba crystal/command/format.cr:26:83 # show explanation for the issue $ ameba --explain crystal/command/format.cr:26:83 # same thing ``` ### Inline disabling One or more rules or one or more group of rules can be disabled using inline directives: ```crystal # ameba:disable Style/LargeNumbers time = Time.epoch(1483859302) time = Time.epoch(1483859302) # ameba:disable Style/LargeNumbers, Lint/UselessAssign time = Time.epoch(1483859302) # ameba:disable Style, Lint ``` ## Editor integration * Vim: [vim-crystal](https://github.com/rhysd/vim-crystal) (via [Syntastic](https://github.com/vim-syntastic/syntastic)) * Emacs: [ameba.el](https://github.com/veelenga/ameba.el) * Sublime Text: [Sublime Linter Ameba](https://github.com/epergo/SublimeLinter-contrib-ameba) ## Credits & inspirations - [Crystal Language](crystal-lang.org) - [Rubocop](http://rubocop.readthedocs.io/en/latest/) - [Credo](http://credo-ci.org/) - [Dogma](https://github.com/lpil/dogma) ## Contributors - [veelenga](https://github.com/veelenga) Vitalii Elenhaupt - creator, maintainer