SwiftLint/Source/SwiftLintFramework/Rules/Style/EmptyParenthesesWithTrailin...

98 lines
4.2 KiB
Swift

import Foundation
import SourceKittenFramework
public struct EmptyParenthesesWithTrailingClosureRule: SubstitutionCorrectableASTRule, ConfigurationProviderRule,
AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "empty_parentheses_with_trailing_closure",
name: "Empty Parentheses with Trailing Closure",
description: "When using trailing closures, empty parentheses should be avoided " +
"after the method call.",
kind: .style,
nonTriggeringExamples: [
"[1, 2].map { $0 + 1 }\n",
"[1, 2].map({ $0 + 1 })\n",
"[1, 2].reduce(0) { $0 + $1 }",
"[1, 2].map { number in\n number + 1 \n}\n",
"let isEmpty = [1, 2].isEmpty()\n",
"UIView.animateWithDuration(0.3, animations: {\n" +
" self.disableInteractionRightView.alpha = 0\n" +
"}, completion: { _ in\n" +
" ()\n" +
"})"
],
triggeringExamples: [
"[1, 2].map↓() { $0 + 1 }\n",
"[1, 2].map↓( ) { $0 + 1 }\n",
"[1, 2].map↓() { number in\n number + 1 \n}\n",
"[1, 2].map↓( ) { number in\n number + 1 \n}\n",
"func foo() -> [Int] {\n return [1, 2].map↓() { $0 + 1 }\n}\n"
],
corrections: [
"[1, 2].map↓() { $0 + 1 }\n": "[1, 2].map { $0 + 1 }\n",
"[1, 2].map↓( ) { $0 + 1 }\n": "[1, 2].map { $0 + 1 }\n",
"[1, 2].map↓() { number in\n number + 1 \n}\n": "[1, 2].map { number in\n number + 1 \n}\n",
"[1, 2].map↓( ) { number in\n number + 1 \n}\n": "[1, 2].map { number in\n number + 1 \n}\n",
"func foo() -> [Int] {\n return [1, 2].map↓() { $0 + 1 }\n}\n":
"func foo() -> [Int] {\n return [1, 2].map { $0 + 1 }\n}\n",
"class C {\n#if true\nfunc f() {\n[1, 2].map↓() { $0 + 1 }\n}\n#endif\n}":
"class C {\n#if true\nfunc f() {\n[1, 2].map { $0 + 1 }\n}\n#endif\n}"
]
)
private static let emptyParenthesesRegex = regex("^\\s*\\(\\s*\\)")
public func validate(file: SwiftLintFile, kind: SwiftExpressionKind,
dictionary: SourceKittenDictionary) -> [StyleViolation] {
return violationRanges(in: file, kind: kind, dictionary: dictionary).map {
StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, characterOffset: $0.location))
}
}
public func substitution(for violationRange: NSRange, in file: SwiftLintFile) -> (NSRange, String)? {
return (violationRange, "")
}
public func violationRanges(in file: SwiftLintFile, kind: SwiftExpressionKind,
dictionary: SourceKittenDictionary) -> [NSRange] {
guard kind == .call else {
return []
}
guard let offset = dictionary.offset,
let length = dictionary.length,
let nameOffset = dictionary.nameOffset,
let nameLength = dictionary.nameLength,
let bodyLength = dictionary.bodyLength,
bodyLength > 0 else {
return []
}
// avoid the more expensive regex match if there's no trailing closure in the substructure
if SwiftVersion.current >= .fourDotTwo,
dictionary.substructure.last?.expressionKind != .closure {
return []
}
let rangeStart = nameOffset + nameLength
let rangeLength = (offset + length) - (nameOffset + nameLength)
let byteRange = ByteRange(location: rangeStart, length: rangeLength)
let regex = EmptyParenthesesWithTrailingClosureRule.emptyParenthesesRegex
guard let range = file.stringView.byteRangeToNSRange(byteRange),
let match = regex.firstMatch(in: file.contents, options: [], range: range)?.range,
match.location == range.location
else {
return []
}
return [match]
}
}