SwiftLint/Source/SwiftLintFramework/Rules/Lint/UnownedVariableCaptureRule....

49 lines
1.7 KiB
Swift

import SwiftSyntax
struct UnownedVariableCaptureRule: SwiftSyntaxRule, OptInRule, ConfigurationProviderRule {
var configuration = SeverityConfiguration(.warning)
init() {}
static let description = RuleDescription(
identifier: "unowned_variable_capture",
name: "Unowned Variable Capture",
description: "Prefer capturing references as weak to avoid potential crashes",
kind: .lint,
nonTriggeringExamples: [
Example("foo { [weak self] in _ }"),
Example("foo { [weak self] param in _ }"),
Example("foo { [weak bar] in _ }"),
Example("foo { [weak bar] param in _ }"),
Example("foo { bar in _ }"),
Example("foo { $0 }"),
Example("""
final class First {}
final class Second {
unowned var value: First
init(value: First) {
self.value = value
}
}
""")
],
triggeringExamples: [
Example("foo { [↓unowned self] in _ }"),
Example("foo { [↓unowned bar] in _ }"),
Example("foo { [bar, ↓unowned self] in _ }")
]
)
func makeVisitor(file: SwiftLintFile) -> ViolationsSyntaxVisitor {
UnownedVariableCaptureRuleVisitor(viewMode: .sourceAccurate)
}
}
private final class UnownedVariableCaptureRuleVisitor: ViolationsSyntaxVisitor {
override func visitPost(_ node: TokenSyntax) {
if case .keyword(.unowned) = node.tokenKind, node.parent?.is(ClosureCaptureItemSpecifierSyntax.self) == true {
violations.append(node.positionAfterSkippingLeadingTrivia)
}
}
}