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

54 lines
2.5 KiB
Swift

import SourceKittenFramework
public struct LegacyMultipleRule: OptInRule, ConfigurationProviderRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "legacy_multiple",
name: "Legacy Multiple",
description: "Prefer using the `isMultiple(of:)` function instead of using the remainder operator (`%`).",
kind: .idiomatic,
minSwiftVersion: .five,
nonTriggeringExamples: [
Example("cell.contentView.backgroundColor = indexPath.row.isMultiple(of: 2) ? .gray : .white"),
Example("guard count.isMultiple(of: 2) else { throw DecodingError.dataCorrupted(...) }"),
Example("sanityCheck(bytes > 0 && bytes.isMultiple(of: 4), \"capacity must be multiple of 4 bytes\")"),
Example("guard let i = reversedNumbers.firstIndex(where: { $0.isMultiple(of: 2) }) else { return }"),
Example("""
let constant = 56
let isMultiple = value.isMultiple(of: constant)
"""),
Example("""
let constant = 56
let secret = value % constant == 5
"""),
Example("let secretValue = (value % 3) + 2")
],
triggeringExamples: [
Example("cell.contentView.backgroundColor = indexPath.row ↓% 2 == 0 ? .gray : .white"),
Example("cell.contentView.backgroundColor = indexPath.row ↓% 2 != 0 ? .gray : .white"),
Example("guard count ↓% 2 == 0 else { throw DecodingError.dataCorrupted(...) }"),
Example("sanityCheck(bytes > 0 && bytes ↓% 4 == 0, \"capacity must be multiple of 4 bytes\")"),
Example("guard let i = reversedNumbers.firstIndex(where: { $0 ↓% 2 == 0 }) else { return }"),
Example("""
let constant = 56
let isMultiple = value ↓% constant == 0
""")
]
)
// MARK: - Rule
public func validate(file: SwiftLintFile) -> [StyleViolation] {
let pattern = "(?!\\b\\s*)%\(RegexHelpers.variableOrNumber)[=!]=\\s*0\\b"
return file.match(pattern: pattern, excludingSyntaxKinds: SyntaxKind.commentAndStringKinds)
.map {
StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, characterOffset: $0.location))
}
}
}