SwiftLint/Source/SwiftLintFramework/Rules/Idiomatic/ObjectLiteralRule.swift

100 lines
4.3 KiB
Swift

import SourceKittenFramework
public struct ObjectLiteralRule: ASTRule, ConfigurationProviderRule, OptInRule {
public var configuration = ObjectLiteralConfiguration()
public init() {}
public static let description = RuleDescription(
identifier: "object_literal",
name: "Object Literal",
description: "Prefer object literals over image and color inits.",
kind: .idiomatic,
nonTriggeringExamples: [
Example("let image = #imageLiteral(resourceName: \"image.jpg\")"),
Example("let color = #colorLiteral(red: 0.9607843161, green: 0.7058823705, blue: 0.200000003, alpha: 1)"),
Example("let image = UIImage(named: aVariable)"),
Example("let image = UIImage(named: \"interpolated \\(variable)\")"),
Example("let color = UIColor(red: value, green: value, blue: value, alpha: 1)"),
Example("let image = NSImage(named: aVariable)"),
Example("let image = NSImage(named: \"interpolated \\(variable)\")"),
Example("let color = NSColor(red: value, green: value, blue: value, alpha: 1)")
],
triggeringExamples: ["", ".init"].flatMap { (method: String) -> [Example] in
["UI", "NS"].flatMap { (prefix: String) -> [Example] in
[
Example("let image = ↓\(prefix)Image\(method)(named: \"foo\")"),
Example("let color = ↓\(prefix)Color\(method)(red: 0.3, green: 0.3, blue: 0.3, alpha: 1)"),
// swiftlint:disable:next line_length
Example("let color = ↓\(prefix)Color\(method)(red: 100 / 255.0, green: 50 / 255.0, blue: 0, alpha: 1)"),
Example("let color = ↓\(prefix)Color\(method)(white: 0.5, alpha: 1)")
]
}
}
)
public func validate(file: SwiftLintFile, kind: SwiftExpressionKind,
dictionary: SourceKittenDictionary) -> [StyleViolation] {
guard kind == .call,
let offset = dictionary.offset,
(configuration.imageLiteral && isImageNamedInit(dictionary: dictionary, file: file)) ||
(configuration.colorLiteral && isColorInit(dictionary: dictionary, file: file)) else {
return []
}
return [
StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severityConfiguration.severity,
location: Location(file: file, byteOffset: offset))
]
}
private func isImageNamedInit(dictionary: SourceKittenDictionary, file: SwiftLintFile) -> Bool {
guard let name = dictionary.name,
inits(forClasses: ["UIImage", "NSImage"]).contains(name),
case let arguments = dictionary.enclosedArguments,
arguments.compactMap({ $0.name }) == ["named"],
let argument = arguments.first,
case let kinds = kinds(forArgument: argument, file: file),
kinds == [.string] else {
return false
}
return true
}
private func isColorInit(dictionary: SourceKittenDictionary, file: SwiftLintFile) -> Bool {
guard let name = dictionary.name,
inits(forClasses: ["UIColor", "NSColor"]).contains(name),
case let arguments = dictionary.enclosedArguments,
case let argumentsNames = arguments.compactMap({ $0.name }),
argumentsNames == ["red", "green", "blue", "alpha"] || argumentsNames == ["white", "alpha"],
validateColorKinds(arguments: arguments, file: file) else {
return false
}
return true
}
private func inits(forClasses names: [String]) -> [String] {
return names.flatMap { name in
[
name,
name + ".init"
]
}
}
private func validateColorKinds(arguments: [SourceKittenDictionary], file: SwiftLintFile) -> Bool {
for dictionary in arguments where kinds(forArgument: dictionary, file: file) != [.number] {
return false
}
return true
}
private func kinds(forArgument argument: SourceKittenDictionary, file: SwiftLintFile) -> Set<SyntaxKind> {
return argument.bodyByteRange.map { Set(file.syntaxMap.kinds(inByteRange: $0)) } ?? []
}
}