All changes, no matter how trivial, must be done via pull request. Commits
should never be made directly on the master
branch.
If you have commit access to SwiftLint and believe your change to be trivial and not worth waiting for review, you may open a pull request and merge immediately, but this should be the exception, not the norm.
This SwiftLint repository uses submodules for its dependencies.
This means that if you decide to fork this repository to contribute to SwiftLint,
don't forget to checkout the submodules as well when cloning, by running
git submodule update --init --recursive
after cloning.
See more info in the README.
SwiftLint supports building via Xcode and Swift Package Manager on macOS, and with Swift Package Manager on Linux. When contributing code changes, please ensure that all three supported build methods continue to work and pass tests.
$ script/cibuild
$ swift test
$ make docker_test
XCTest functions that are added need to be mirrored in the allTests
static var
in the test class extensions at the bottom of the test files.
New rules should be added in the Source/SwiftLintFramework/Rules
directory.
Rules should conform to either the Rule
or ASTRule
protocols.
To activate a rule, add the rule to masterRuleList
in MasterRuleList.swift
.
All new rules or changes to existing rules should be accompanied by unit tests.
Whenever possible, prefer adding tests via the triggeringExamples
and
nonTriggeringExamples
properties of a rule's description
rather than adding
those test cases in the unit tests directly. This makes it easier to understand
what rules do by reading their source, and simplifies adding more test cases
over time. This way adding a unit test for your new Rule is just a matter of
adding a test case in RulesTests.swift
which simply calls
verifyRule(YourNewRule.description)
.
If your rule supports user-configurable options via .swiftlint.yml
, you can
accomplish this by conforming to ConfigurationProviderRule
. You must provide a
configuration object via the configuration
property:
- The object provided must conform to
RuleConfiguration
. - There are several provided
RuleConfiguration
s that cover the common patterns like configuring violation severity, violation severity levels, and evaluating names. - If none of the provided
RuleConfiguration
s are applicable, you can create one specifically for your rule.
See ForceCastRule
for a rule that allows severity configuration,
FileLengthRule
for a rule that has multiple severity levels,
VariableNameRule
for a rule that allows name evaluation configuration:
force_cast: warning
file_length:
warning: 800
error: 1200
variable_name:
min_length:
warning: 3
error: 2
max_length: 20
excluded: id
If your rule is configurable, but does not fit the pattern of
ConfigurationProviderRule
, you can conform directly to Rule
:
init(configuration: AnyObject) throws
will be passed the result of parsing the value from.swiftlint.yml
associated with your rule'sidentifier
as a key (if present).configuration
may be of any type supported by YAML (e.g.Int
,String
,Array
,Dictionary
, etc.).- This initializer must throw if it does not understand the configuration, or it cannot be fully initialized with the configuration and default values.
- By convention, a failing initializer throws
ConfigurationError.UnknownConfiguration
. - If this initializer fails, your rule will be initialized with its default
values by calling
init()
.
All changes should be made via pull requests on GitHub.
When issuing a pull request, please add a summary of your changes to
the CHANGELOG.md
file.
We follow the same syntax as CocoaPods' CHANGELOG.md:
- One Markdown unnumbered list item describing the change.
- 2 trailing spaces on the last line describing the change.
- A list of Markdown hyperlinks to the contributors to the change. One entry per line. Usually just one.
- A list of Markdown hyperlinks to the issues the change addresses. One entry per line. Usually just one.
- All CHANGELOG.md content is hard-wrapped at 80 characters.