SwiftLint/Source/SwiftLintFramework/Rules/Lint/OverrideInExtensionRule.swift

65 lines
2.5 KiB
Swift

import SourceKittenFramework
public struct OverrideInExtensionRule: ConfigurationProviderRule, OptInRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "override_in_extension",
name: "Override in Extension",
description: "Extensions shouldn't override declarations.",
kind: .lint,
nonTriggeringExamples: [
Example("extension Person {\n var age: Int { return 42 }\n}\n"),
Example("extension Person {\n func celebrateBirthday() {}\n}\n"),
Example("class Employee: Person {\n override func celebrateBirthday() {}\n}\n"),
Example("""
class Foo: NSObject {}
extension Foo {
override var description: String { return "" }
}
"""),
Example("""
struct Foo {
class Bar: NSObject {}
}
extension Foo.Bar {
override var description: String { return "" }
}
""")
],
triggeringExamples: [
Example("extension Person {\n override ↓var age: Int { return 42 }\n}\n"),
Example("extension Person {\n override ↓func celebrateBirthday() {}\n}\n")
]
)
public func validate(file: SwiftLintFile) -> [StyleViolation] {
let collector = NamespaceCollector(dictionary: file.structureDictionary)
let elements = collector.findAllElements(of: [.class, .struct, .enum, .extension])
let susceptibleNames = Set(elements.compactMap { $0.kind == .class ? $0.name : nil })
return elements
.filter { $0.kind == .extension && !susceptibleNames.contains($0.name) }
.flatMap { element in
return element.dictionary.substructure.compactMap { element -> ByteCount? in
guard element.declarationKind != nil,
element.enclosedSwiftAttributes.contains(.override),
let offset = element.offset
else {
return nil
}
return offset
}
}
.map {
StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, byteOffset: $0))
}
}
}