5.7 KiB
Unused ![Build Status](https://travis-ci.org/joshuaclayton/unused.svg?branch=master)
A command line tool to identify unused code.
"What kinds of projects can I used it on?"
Anything.
Yes, literally anything.
It's probably best if you have a ctags file it can read from (it looks in
.git
, tmp
, and the root directory for a tags
file), but if you have
another way to pipe a bunch of methods/functions/classes/modules/whatever in,
that works too.
Right now, there are some special cases built in for Rails and Phoenix apps (specifically, assumptions about what's fine to only have one reference to, e.g. Controllers in Rails and Views in Phoenix), but it'll work on Rubygems, Elixir packages, or anything else.
That said, be confident the code you're removing won't break your program. Especially with projects built in Ruby, Elixir, or JavaScript, there are ways to dynamically trigger or define behavior that may be surprising. A test suite can help here, but still cannot determine every possible execution path.
Installing
Homebrew (Recommended)
You can install my formulae via Homebrew with brew tap
:
brew tap joshuaclayton/formulae
Next, run:
brew install unused
Alternatively, you can install by hand.
Installing by hand
This project uses Haskell and Stack.
Once you have these tools installed:
stack setup
stack install
This will generate a binary in $HOME/.local/bin
; ensure this directory is in
your $PATH
.
Using Unused
unused
attempts to read from common tags file locations (.git/tags
,
tags
, and tmp/tags
).
In an application where the tags file exists, run:
unused
If you want to specify a custom tags file, or load tokens from somewhere else, run:
cat .custom/tags | unused --stdin
To view more usage options, run:
unused --help
Custom Configuration
The first time you use unused
, you might see a handful of false positives.
unused
will look in two additional locations in an attempt to load
additional custom configuration to help improve this.
Configuration format
# Language or framework name
# e.g. Rails, Ruby, Go, Play
- name: Framework or language
# Collection of matches allowed to have one occurrence
autoLowLikelihood:
# Low likelihood match name
- name: ActiveModel::Serializer
# Flag to capture only capitalized names
# e.g. would match `ApplicationController`, not `with_comments`
classOrModule: true
# Matcher for `.*Serializer$`
# e.g. `UserSerializer`, `ProjectSerializer`
termEndsWith: Serializer
# Matcher for `^with_.*`
# e.g. `with_comments`, `with_previous_payments`
termStartsWith: with_
# Matcher for `^ApplicationController$`
termEquals: ApplicationController
# Matcher for `.*_factory.ex`
# e.g. `lib/appname/user_factory.ex`, `lib/appname/project_factory.ex`
pathEndsWith: _factory.ex
# Matcher for `^app/policies.*`
# e.g. `app/policies/user_policy.rb`, `app/policies/project_policy.rb`
pathStartsWith: app/policies
# list of termEquals
# Matcher allowing any exact match from a list
allowedTerms:
- index?
- edit?
- create?
~/.unused.yml
The first location is ~/.unused.yml
. This should hold widely-used
configuration roughly applicable across projects. Here's an example of what
might be present:
- name: Rails
autoLowLikelihood:
- name: ActiveModel::Serializer
termEndsWith: Serializer
classOrModule: true
- name: Pundit
termEndsWith: Policy
classOrModule: true
pathEndsWith: .rb
- name: Pundit Helpers
allowedTerms:
- Scope
- index?
- new?
- create?
- show?
- edit?
- destroy?
- resolve
- name: JSONAPI::Resources
termEndsWith: Resource
classOrModule: true
pathStartsWith: app/resources
- name: JSONAPI::Resources Helpers
allowedTerms:
- updatable_fields
pathStartsWith: app/resources
I tend to work on different APIs, and the two libraries I most commonly use have a fairly similar pattern when it comes to class naming. They both also use that naming structure to identify serializers automatically, meaning they very well may only be referenced once in the entire application (when they're initially defined).
Similarly, with Pundit, an authorization library, naming conventions often mean only one reference to the class name.
This is a file that might grow, but is focused on widely-used patterns across codebases. You might even want to check it into your dotfiles.
APP_ROOT/.unused.yml
The second location is APP_ROOT/.unused.yml
. This is where any
project-specific settings might live. If you're working on a library before
extracting to a gem or package, you might have this configuration take that
into account.
Validation
unused
will attempt to parse both of these files, if it finds them. If
either is invalid either due to missing or mistyped keys, an error will be
displayed.
Requirements
Unused leverages Ag to
analyze the codebase; as such, you'll need to have ag
available in your
$PATH
. This is set as an explicit dependency in Homebrew.
Testing
To run the test suite, run:
stack test
License
Copyright 2016 Josh Clayton. See the LICENSE.