SwiftLint/Source/SwiftLintFramework/Rules/Style/ControlStatementRule.swift

116 lines
4.7 KiB
Swift

import SourceKittenFramework
public struct ControlStatementRule: ConfigurationProviderRule, AutomaticTestableRule {
public var configuration = SeverityConfiguration(.warning)
public init() {}
public static let description = RuleDescription(
identifier: "control_statement",
name: "Control Statement",
description:
"`if`, `for`, `guard`, `switch`, `while`, and `catch` statements shouldn't unnecessarily wrap their " +
"conditionals or arguments in parentheses.",
kind: .style,
nonTriggeringExamples: [
"if condition {\n",
"if (a, b) == (0, 1) {\n",
"if (a || b) && (c || d) {\n",
"if (min...max).contains(value) {\n",
"if renderGif(data) {\n",
"renderGif(data)\n",
"for item in collection {\n",
"for (key, value) in dictionary {\n",
"for (index, value) in enumerate(array) {\n",
"for var index = 0; index < 42; index++ {\n",
"guard condition else {\n",
"while condition {\n",
"} while condition {\n",
"do { ; } while condition {\n",
"switch foo {\n",
"do {\n} catch let error as NSError {\n}",
"foo().catch(all: true) {}",
"if max(a, b) < c {\n",
"switch (lhs, rhs) {\n"
],
triggeringExamples: [
"↓if (condition) {\n",
"↓if(condition) {\n",
"↓if (condition == endIndex) {\n",
"↓if ((a || b) && (c || d)) {\n",
"↓if ((min...max).contains(value)) {\n",
"↓for (item in collection) {\n",
"↓for (var index = 0; index < 42; index++) {\n",
"↓for(item in collection) {\n",
"↓for(var index = 0; index < 42; index++) {\n",
"↓guard (condition) else {\n",
"↓while (condition) {\n",
"↓while(condition) {\n",
"} ↓while (condition) {\n",
"} ↓while(condition) {\n",
"do { ; } ↓while(condition) {\n",
"do { ; } ↓while (condition) {\n",
"↓switch (foo) {\n",
"do {\n} ↓catch(let error as NSError) {\n}",
"↓if (max(a, b) < c) {\n"
]
)
public func validate(file: SwiftLintFile) -> [StyleViolation] {
let statements = ["if", "for", "guard", "switch", "while", "catch"]
let statementPatterns: [String] = statements.map { statement -> String in
let isGuard = statement == "guard"
let isSwitch = statement == "switch"
let elsePattern = isGuard ? "else\\s*" : ""
let clausePattern = isSwitch ? "[^,{]*" : "[^{]*"
return "\(statement)\\s*\\(\(clausePattern)\\)\\s*\(elsePattern)\\{"
}
return statementPatterns.flatMap { pattern -> [StyleViolation] in
return file.match(pattern: pattern)
.filter { match, syntaxKinds -> Bool in
let matchString = file.contents.substring(from: match.location, length: match.length)
return !isFalsePositive(matchString, syntaxKind: syntaxKinds.first)
}
.filter { match, _ -> Bool in
let contents = file.contents.bridge()
guard let byteOffset = contents.NSRangeToByteRange(start: match.location, length: 1)?.location,
let outerKind = file.structureDictionary.kinds(forByteOffset: byteOffset).last else {
return true
}
return SwiftExpressionKind(rawValue: outerKind.kind) != .call
}
.map { match, _ -> StyleViolation in
return StyleViolation(ruleDescription: type(of: self).description,
severity: configuration.severity,
location: Location(file: file, characterOffset: match.location))
}
}
}
fileprivate func isFalsePositive(_ content: String, syntaxKind: SyntaxKind?) -> Bool {
if syntaxKind != .keyword {
return true
}
guard let lastClosingParenthesePosition = content.lastIndex(of: ")") else {
return false
}
var depth = 0
var index = 0
for char in content {
if char == ")" {
if index != lastClosingParenthesePosition && depth == 1 {
return true
}
depth -= 1
} else if char == "(" {
depth += 1
}
index += 1
}
return false
}
}