SwiftLint/Source/SwiftLintFramework/Rules/Lint/UnusedClosureParameterRule....

189 lines
8.6 KiB
Swift

import Foundation
import SourceKittenFramework
public struct UnusedClosureParameterRule: SubstitutionCorrectableASTRule, ConfigurationProviderRule,
AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "unused_closure_parameter",
name: "Unused Closure Parameter",
description: "Unused parameter in a closure should be replaced with _.",
kind: .lint,
nonTriggeringExamples: [
"[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 { _ in\n 3 \n}\n",
"[1, 2].something { number, idx in\n return number * idx\n}\n",
"let isEmpty = [1, 2].isEmpty()\n",
"violations.sorted(by: { lhs, rhs in \n return lhs.location > rhs.location\n})\n",
"rlmConfiguration.migrationBlock.map { rlmMigration in\n" +
"return { migration, schemaVersion in\n" +
"rlmMigration(migration.rlmMigration, schemaVersion)\n" +
"}\n" +
"}",
"genericsFunc { (a: Type, b) in\n" +
"a + b\n" +
"}\n",
"var label: UILabel = { (lbl: UILabel) -> UILabel in\n" +
" lbl.backgroundColor = .red\n" +
" return lbl\n" +
"}(UILabel())\n",
"hoge(arg: num) { num in\n" +
" return num\n" +
"}\n",
"""
({ (manager: FileManager) in
print(manager)
})(FileManager.default)
""",
"""
withPostSideEffect { input in
if true { print("\\(input)") }
}
""",
"""
viewModel?.profileImage.didSet(weak: self) { (self, profileImage) in
self.profileImageView.image = profileImage
}
"""
],
triggeringExamples: [
"[1, 2].map { ↓number in\n return 3\n}\n",
"[1, 2].map { ↓number in\n return numberWithSuffix\n}\n",
"[1, 2].map { ↓number in\n return 3 // number\n}\n",
"[1, 2].map { ↓number in\n return 3 \"number\"\n}\n",
"[1, 2].something { number, ↓idx in\n return number\n}\n",
"genericsFunc { (↓number: TypeA, idx: TypeB) in return idx\n}\n",
"hoge(arg: num) { ↓num in\n" +
"}\n",
"fooFunc { ↓아 in\n }",
"func foo () {\n bar { ↓number in\n return 3\n}\n",
"""
viewModel?.profileImage.didSet(weak: self) { (↓self, profileImage) in
profileImageView.image = profileImage
}
"""
],
corrections: [
"[1, 2].map { ↓number in\n return 3\n}\n":
"[1, 2].map { _ in\n return 3\n}\n",
"[1, 2].map { ↓number in\n return numberWithSuffix\n}\n":
"[1, 2].map { _ in\n return numberWithSuffix\n}\n",
"[1, 2].map { ↓number in\n return 3 // number\n}\n":
"[1, 2].map { _ in\n return 3 // number\n}\n",
"[1, 2].map { ↓number in\n return 3 \"number\"\n}\n":
"[1, 2].map { _ in\n return 3 \"number\"\n}\n",
"[1, 2].something { number, ↓idx in\n return number\n}\n":
"[1, 2].something { number, _ in\n return number\n}\n",
"genericsFunc(closure: { (↓int: Int) -> Void in // do something\n}\n":
"genericsFunc(closure: { (_: Int) -> Void in // do something\n}\n",
"genericsFunc { (↓a, ↓b: Type) -> Void in\n}\n":
"genericsFunc { (_, _: Type) -> Void in\n}\n",
"genericsFunc { (↓a: Type, ↓b: Type) -> Void in\n}\n":
"genericsFunc { (_: Type, _: Type) -> Void in\n}\n",
"genericsFunc { (↓a: Type, ↓b) -> Void in\n}\n":
"genericsFunc { (_: Type, _) -> Void in\n}\n",
"genericsFunc { (a: Type, ↓b) -> Void in\nreturn a\n}\n":
"genericsFunc { (a: Type, _) -> Void in\nreturn a\n}\n",
"hoge(arg: num) { ↓num in\n}\n":
"hoge(arg: num) { _ in\n}\n",
"func foo () {\n bar { ↓number in\n return 3\n}\n":
"func foo () {\n bar { _ in\n return 3\n}\n",
"class C {\n #if true\n func f() {\n [1, 2].map { ↓number in\n return 3\n }\n }\n #endif\n}":
"class C {\n #if true\n func f() {\n [1, 2].map { _ in\n return 3\n }\n }\n #endif\n}"
]
)
public func validate(file: SwiftLintFile, kind: SwiftExpressionKind,
dictionary: SourceKittenDictionary) -> [StyleViolation] {
return violationRanges(in: file, dictionary: dictionary, kind: kind).map { range, name in
let reason = "Unused parameter \"\(name)\" in a closure should be replaced with _."
return StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, characterOffset: range.location),
reason: reason)
}
}
public func violationRanges(in file: SwiftLintFile, kind: SwiftExpressionKind,
dictionary: SourceKittenDictionary) -> [NSRange] {
return violationRanges(in: file, dictionary: dictionary, kind: kind).map { $0.range }
}
public func substitution(for violationRange: NSRange, in file: SwiftLintFile) -> (NSRange, String) {
return (violationRange, "_")
}
private func violationRanges(in file: SwiftLintFile, dictionary: SourceKittenDictionary,
kind: SwiftExpressionKind) -> [(range: NSRange, name: String)] {
guard kind == .call,
!isClosure(dictionary: dictionary),
let offset = dictionary.offset,
let length = dictionary.length,
let nameOffset = dictionary.nameOffset,
let nameLength = dictionary.nameLength,
let bodyLength = dictionary.bodyLength,
bodyLength > 0 else {
return []
}
let rangeStart = nameOffset + nameLength
let rangeLength = (offset + length) - (nameOffset + nameLength)
let parameters = dictionary.enclosedVarParameters
let contents = file.contents.bridge()
return parameters.compactMap { param -> (NSRange, String)? in
guard let paramOffset = param.offset,
let name = param.name,
name != "_",
let regex = try? NSRegularExpression(pattern: name,
options: [.ignoreMetacharacters]),
let range = contents.byteRangeToNSRange(start: rangeStart, length: rangeLength)
else {
return nil
}
let paramLength = name.lengthOfBytes(using: .utf8)
let matches = regex.matches(in: file.contents, options: [], range: range).ranges()
for range in matches {
guard let byteRange = contents.NSRangeToByteRange(start: range.location,
length: range.length),
// if it's the parameter declaration itself, we should skip
byteRange.location > paramOffset,
case let tokens = file.syntaxMap.tokens(inByteRange: byteRange) else {
continue
}
let token = tokens.first(where: { token -> Bool in
return (token.kind == .identifier
|| (token.kind == .keyword && name == "self")) &&
token.offset == byteRange.location &&
token.length == byteRange.length
})
// found a usage, there's no violation!
guard token == nil else {
return nil
}
}
if let range = contents.byteRangeToNSRange(start: paramOffset, length: paramLength) {
return (range, name)
}
return nil
}
}
private func isClosure(dictionary: SourceKittenDictionary) -> Bool {
return dictionary.name.flatMap { name -> Bool in
let length = name.bridge().length
let range = NSRange(location: 0, length: length)
return regex("\\A[\\s\\(]*?\\{").firstMatch(in: name, options: [], range: range) != nil
} ?? false
}
}