SwiftLint/Source/SwiftLintFramework/Rules/Style/EmptyParametersRule.swift

62 lines
2.8 KiB
Swift

import Foundation
import SourceKittenFramework
public struct EmptyParametersRule: ConfigurationProviderRule, SubstitutionCorrectableRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "empty_parameters",
name: "Empty Parameters",
description: "Prefer `() -> ` over `Void -> `.",
kind: .style,
nonTriggeringExamples: [
Example("let abc: () -> Void = {}\n"),
Example("func foo(completion: () -> Void)\n"),
Example("func foo(completion: () thows -> Void)\n"),
Example("let foo: (ConfigurationTests) -> Void throws -> Void)\n"),
Example("let foo: (ConfigurationTests) -> Void throws -> Void)\n"),
Example("let foo: (ConfigurationTests) ->Void throws -> Void)\n")
],
triggeringExamples: [
Example("let abc: ↓(Void) -> Void = {}\n"),
Example("func foo(completion: ↓(Void) -> Void)\n"),
Example("func foo(completion: ↓(Void) throws -> Void)\n"),
Example("let foo: ↓(Void) -> () throws -> Void)\n")
],
corrections: [
Example("let abc: ↓(Void) -> Void = {}\n"): Example("let abc: () -> Void = {}\n"),
Example("func foo(completion: ↓(Void) -> Void)\n"): Example("func foo(completion: () -> Void)\n"),
Example("func foo(completion: ↓(Void) throws -> Void)\n"):
Example("func foo(completion: () throws -> Void)\n"),
Example("let foo: ↓(Void) -> () throws -> Void)\n"): Example("let foo: () -> () throws -> Void)\n")
]
)
public func validate(file: SwiftLintFile) -> [StyleViolation] {
return violationRanges(in: file).map {
StyleViolation(ruleDescription: Self.description,
severity: configuration.severity,
location: Location(file: file, characterOffset: $0.location))
}
}
public func violationRanges(in file: SwiftLintFile) -> [NSRange] {
let voidPattern = "\\(Void\\)"
let pattern = voidPattern + "\\s*(throws\\s+)?->"
let excludingPattern = "->\\s*" + pattern // excludes curried functions
return file.match(pattern: pattern,
excludingSyntaxKinds: SyntaxKind.commentAndStringKinds,
excludingPattern: excludingPattern).compactMap { range in
let voidRegex = regex(voidPattern)
return voidRegex.firstMatch(in: file.contents, options: [], range: range)?.range
}
}
public func substitution(for violationRange: NSRange, in file: SwiftLintFile) -> (NSRange, String)? {
return (violationRange, "()")
}
}