Code style linter for Crystal
(a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm)
Ameba is a static code analysis tool for the Crystal language. It enforces a consistent Crystal code style, also catches code smells and wrong code constructions.
How it works
Ameba's "fingerlike projections" are rules. Each rule makes the inspection for that or another problem in the source code. Currently rules are able to:
- [x] simply validate lines of source code
- [x] traverse AST using
- [x] tokenize sources using
Crystal::Lexerand iterate through tokens
- [ ] do semantics analysis using
As a project dependency:
Add this to your application's
development_dependencies: ameba: github: veelenga/ameba
bin/ameba binary within your project directory while running
You may also want to use it on Travis:
# .travis.yml language: crystal install: - crystal deps 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.
$ brew tap veelenga/tap $ brew install ameba
$ git clone https://github.com/veelenga/ameba && cd ameba $ make install
ameba binary within your project directory to catch code issues:
$ ameba Inspecting 52 files. .........................F.......F........F......... src/ameba/ast/traverse.cr:27:5 PredicateName: Favour method name 'node?' over 'is_node?' src/ameba/rules/empty_expression.cr:42:7 LiteralInCondition: Literal value found in conditional src/ameba/rules/empty_expression.cr:30:7 UnlessElse: Favour if over unless with else Finished in 10.53 milliseconds 52 inspected, 3 failures.
Default configuration file is
It allows to configure rule properties, disable specific rules and exclude sources from the rules.
Generate new file by running
Writing a new Rule
Adding a new rule is as simple as inheriting from
Ameba::Rule::Base struct and implementing
a logic to detect a problem in the source file:
struct MySuperRule < Ameba::Rule::Base # This is a required method to be implemented by the rule. # Source will be passed here. If rule detects an issue in the source, # it reports an error: # # source.error rule, location, message # def test(source) # TODO: test source end end
As soon as a custom rule is defined, it becomes available in a full set of rules executed by default and also can be configured via config file:
MySuperRule: Enabled: false
Credits & inspirations
- veelenga Vitalii Elenhaupt - creator, maintainer