SwiftLint/Source/SwiftLintFramework/Rules/Performance/ContainsOverRangeNilCompari...

54 lines
2.0 KiB
Swift

import SwiftSyntax
struct ContainsOverRangeNilComparisonRule: SwiftSyntaxRule, OptInRule, ConfigurationProviderRule {
var configuration = SeverityConfiguration(.warning)
init() {}
static let description = RuleDescription(
identifier: "contains_over_range_nil_comparison",
name: "Contains over Range Comparision to Nil",
description: "Prefer `contains` over `range(of:) != nil` and `range(of:) == nil`.",
kind: .performance,
nonTriggeringExamples: [
Example("let range = myString.range(of: \"Test\")"),
Example("myString.contains(\"Test\")"),
Example("!myString.contains(\"Test\")"),
Example("resourceString.range(of: rule.regex, options: .regularExpression) != nil")
],
triggeringExamples: ["!=", "=="].flatMap { comparison in
return [
Example("↓myString.range(of: \"Test\") \(comparison) nil")
]
}
)
func preprocess(syntaxTree: SourceFileSyntax) -> SourceFileSyntax? {
syntaxTree.folded()
}
func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {
Visitor(viewMode: .sourceAccurate)
}
}
private extension ContainsOverRangeNilComparisonRule {
final class Visitor: ViolationsSyntaxVisitor {
override func visitPost(_ node: InfixOperatorExprSyntax) {
guard
let operatorNode = node.operatorOperand.as(BinaryOperatorExprSyntax.self),
operatorNode.operatorToken.tokenKind.isEqualityComparison,
node.rightOperand.is(NilLiteralExprSyntax.self),
let first = node.leftOperand.asFunctionCall,
first.argumentList.onlyElement?.label?.text == "of",
let calledExpression = first.calledExpression.as(MemberAccessExprSyntax.self),
calledExpression.name.text == "range"
else {
return
}
violations.append(first.positionAfterSkippingLeadingTrivia)
}
}
}