SwiftLint/Source/SwiftLintFramework/Rules/Idiomatic/RedundantStringEnumValueRul...

115 lines
4.4 KiB
Swift

import SourceKittenFramework
private func children(of dict: [String: SourceKitRepresentable],
matching kind: SwiftDeclarationKind) -> [[String: SourceKitRepresentable]] {
return dict.substructure.compactMap { subDict in
if let kindString = subDict.kind,
SwiftDeclarationKind(rawValue: kindString) == kind {
return subDict
}
return nil
}
}
public struct RedundantStringEnumValueRule: ASTRule, ConfigurationProviderRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "redundant_string_enum_value",
name: "Redundant String Enum Value",
description: "String enum values can be omitted when they are equal to the enumcase name.",
kind: .idiomatic,
nonTriggeringExamples: [
"enum Numbers: String {\n case one\n case two\n}\n",
"enum Numbers: Int {\n case one = 1\n case two = 2\n}\n",
"enum Numbers: String {\n case one = \"ONE\"\n case two = \"TWO\"\n}\n",
"enum Numbers: String {\n case one = \"ONE\"\n case two = \"two\"\n}\n",
"enum Numbers: String {\n case one, two\n}\n"
],
triggeringExamples: [
"enum Numbers: String {\n case one = ↓\"one\"\n case two = ↓\"two\"\n}\n",
"enum Numbers: String {\n case one = ↓\"one\", two = ↓\"two\"\n}\n",
"enum Numbers: String {\n case one, two = ↓\"two\"\n}\n"
]
)
public func validate(file: File, kind: SwiftDeclarationKind,
dictionary: [String: SourceKitRepresentable]) -> [StyleViolation] {
guard kind == .enum else {
return []
}
// Check if it's a String enum
guard dictionary.inheritedTypes.contains("String") else {
return []
}
let violations = violatingOffsetsForEnum(dictionary: dictionary, file: file)
return violations.map {
StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, byteOffset: $0))
}
}
private func violatingOffsetsForEnum(dictionary: [String: SourceKitRepresentable], file: File) -> [Int] {
var caseCount = 0
var violations = [Int]()
for enumCase in children(of: dictionary, matching: .enumcase) {
caseCount += enumElementsCount(dictionary: enumCase)
violations += violatingOffsetsForEnumCase(dictionary: enumCase, file: file)
}
guard violations.count == caseCount else {
return []
}
return violations
}
private func enumElementsCount(dictionary: [String: SourceKitRepresentable]) -> Int {
return children(of: dictionary, matching: .enumelement).filter({ element in
return !filterEnumInits(dictionary: element).isEmpty
}).count
}
private func violatingOffsetsForEnumCase(dictionary: [String: SourceKitRepresentable], file: File) -> [Int] {
return children(of: dictionary, matching: .enumelement).flatMap { element -> [Int] in
guard let name = element.name else {
return []
}
return violatingOffsetsForEnumElement(dictionary: element, name: name, file: file)
}
}
private func violatingOffsetsForEnumElement(dictionary: [String: SourceKitRepresentable], name: String,
file: File) -> [Int] {
let enumInits = filterEnumInits(dictionary: dictionary)
return enumInits.compactMap { dictionary -> Int? in
guard let offset = dictionary.offset,
let length = dictionary.length else {
return nil
}
// the string would be quoted if offset and length were used directly
let enumCaseName = file.contents.bridge()
.substringWithByteRange(start: offset + 1, length: length - 2) ?? ""
guard enumCaseName == name else {
return nil
}
return offset
}
}
private func filterEnumInits(dictionary: [String: SourceKitRepresentable]) -> [[String: SourceKitRepresentable]] {
return dictionary.elements.filter {
$0.kind == "source.lang.swift.structure.elem.init_expr"
}
}
}