Macros

The following macros are available globally.

  • Macro to be attached to rule configurations. It generates the configuration parsing logic automatically based on the defined @ConfigurationElements.

    Declaration

    Swift

    @attached(member, names: named(apply)
, named(Parent)) public macro AutoConfigParser() = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "AutoConfigParser"
)
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  • Macro that lets an enum with a String raw type automatically conform to AcceptableByConfigurationElement.

    Declaration

    Swift

    @attached(extension, conformances: AcceptableByConfigurationElement, names: named(init(fromAny:context:)
), named(asOption)) public macro AcceptableByConfigurationElement() = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "AcceptableByConfigurationElement"
)
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  • Macro that adds a conformance to the SwiftSyntaxRule protocol and a default makeVisitor(file:) implementation that creates a visitor defined in the rule struct.

    Declaration

    Swift

    @attached(extension, conformances: SwiftSyntaxRule, SwiftSyntaxCorrectableRule, OptInRule, Rule, names: named(makeVisitor(file:)
), named(preprocess(file:)), named(makeRewriter(file:))) public macro SwiftSyntaxRule(foldExpressions: Bool = false, explicitRewriter: Bool = false, correctable: Bool = false, optIn: Bool = false) = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "SwiftSyntaxRule"
)

    Parameters

    foldExpressions

    Setting it to true adds an implementation of preprocess(file:) which folds expressions before they are passed to the visitor.
    explicitRewriter

    Set it to true to add a makeRewriter(file:) implementation which creates a rewriter defined in the rule struct. In this case, the rule automatically conforms to SwiftSyntaxCorrectableRule.
    correctable

    Set it to true to make the rule conform to SwiftSyntaxCorrectableRule without an explicit rewriter.
    optIn

    Set it to true to make the rule conform to OptInRule.
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  • Macro that expands an array into an array of Examples. Elements are usually string literals, but an existing Example expression (e.g. "code".asExample(configuration:)) works too.

    The parameter is typed [Example] (Example is ExpressibleByStringInterpolation), so an unsupported element such as an Int fails as a plain type error on the literal you wrote rather than as a macro-expansion failure.

    Declaration

    Swift

    @freestanding(expression)
public macro examples(_ examples: [Example]) -> [Example] = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "Examples"
)
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  • Macro that expands a dictionary into a dictionary of Examples. Keys and values are usually string literals, but an existing Example expression works too.

    Both key and value are typed Example (which is ExpressibleByStringInterpolation and Hashable), so an unsupported key or value fails as a plain type error on the literal you wrote rather than as a macro-expansion failure.

    Declaration

    Swift

    @freestanding(expression)
public macro corrections(_ examples: [Example : Example]) -> [Example : Example] = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "Corrections"
)
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  • Macro that allows to define an example for a rule. It generates an Example instance with the provided code, configuration and other options. Valuable is that the code passed as the example’s body is compiled, thus making sure that the example is valid Swift code.

    Declaration

    Swift

    @freestanding(expression)
public macro example(configuration: [String : any Sendable]? = nil, testMultiByteOffsets: Bool = true, testWrappingInComment: Bool = true, testWrappingInString: Bool = true, testDisableCommand: Bool = true, testOnLinux: Bool = true, testOnWindows: Bool = true, excludeFromDocumentation: Bool = false, body: () -> Void) -> Example = #externalMacro(
    module: "SwiftLintCoreMacros",
    type: "Example"
)

    Parameters

    configuration

    The untyped configuration to apply to the rule, if deviating from the default configuration.
    testMultiByteOffsets

    Whether the example should be tested by prepending multi-byte grapheme clusters.
    testWrappingInComment

    Whether test shall verify that the example wrapped in a comment doesn’t trigger.
    testWrappingInString

    Whether tests shall verify that the example wrapped into a string doesn’t trigger.
    testDisableCommand

    Whether tests shall verify that the disabled rule (comment in the example) doesn’t trigger.
    testOnLinux

    Whether the example should be tested on Linux.
    testOnWindows

    Whether the example should be tested on Windows.
    excludeFromDocumentation

    Whether the example should be excluded from the rule’s documentation.
    body

    The body of the example, which is compiled to ensure that it is valid Swift code.
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