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sm-eminiakhmetovkapitoshka438
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kapitoshka438
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Add new invisible_characters rule
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+154
-37
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11 files changed

+154
-37
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‎CHANGELOG.md‎

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@@ -12,7 +12,11 @@
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### Enhancements
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* None.
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* Add new default `invisible_characters` rule that detects invisible characters
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like zero-width space (U+200B) and FEFF formatting character (U+FEFF) in
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string literals, which can cause hard-to-debug issues.
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[kapitoshka438](https://github.com/kapitoshka438)
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[#6416](https://github.com/realm/SwiftLint/issues/6045)
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### Bug Fixes
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‎Source/SwiftLintBuiltInRules/Models/BuiltInRules.swift‎

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@@ -95,6 +95,7 @@ public let builtInRules: [any Rule.Type] = [
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IncompatibleConcurrencyAnnotationRule.self,
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IndentationWidthRule.self,
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InvalidSwiftLintCommandRule.self,
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InvisibleCharactersRule.self,
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IsDisjointRule.self,
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JoinedDefaultParameterRule.self,
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LargeTupleRule.self,

‎Source/SwiftLintBuiltInRules/Rules/Lint/InvisibleCharactersRule.swift‎

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import SwiftSyntax
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@SwiftSyntaxRule
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struct InvisibleCharactersRule: Rule {
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var configuration = SeverityConfiguration<Self>(.error)
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static let description = RuleDescription(
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identifier: "invisible_characters",
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name: "Invisible Characters",
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description: "Disallows invisible characters like zero-width space (U+200B) " +
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"and FEFF formatting character (U+FEFF) " +
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"in string literals as they can cause hard-to-debug issues",
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kind: .lint,
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nonTriggeringExamples: [
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Example(#"let s = "HelloWorld""#),
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Example(#"let s = "Hello World""#),
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Example(#"let url = "https://example.com/api""#),
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Example(##"let s = #"Hello World"#"##),
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Example("""
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let multiline = \"\"\"
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Hello
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World
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\"\"\"
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"""),
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Example(#"let empty = """#),
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Example(#"let tab = "Hello\tWorld""#),
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Example(#"let newline = "Hello\nWorld""#),
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Example(#"let unicode = "Hello 👋 World""#),
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],
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triggeringExamples: [
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// swiftlint:disable invisible_characters
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Example(#"let s = "Hello↓​World""#), // U+200B zero-width space
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Example(#"let s = "Hello↓World""#), // U+FEFF formatting character
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Example(#"let url = "https://example↓​.com""#), // U+200B in URL
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Example("""
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let multiline = \"\"\"
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Hello↓​World
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\"\"\"
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"""), // U+200B in multiline string
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Example(#"let s = "Test↓​String↓Here""#), // Multiple invisible characters
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// swiftlint:enable invisible_characters
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]
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)
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private static let invisibleCharacters: Set<Unicode.Scalar> = [
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"\u{200B}", // Zero-width space
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"\u{FEFF}", // Zero-width no-break space (BOM/FEFF)
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]
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}
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private extension InvisibleCharactersRule {
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final class Visitor: ViolationsSyntaxVisitor<ConfigurationType> {
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override func visitPost(_ node: StringLiteralExprSyntax) {
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for segment in node.segments {
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guard let stringSegment = segment.as(StringSegmentSyntax.self) else {
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continue
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}
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let text = stringSegment.content.text
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// Early exit if no invisible characters present
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guard text.unicodeScalars.contains(where: {
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InvisibleCharactersRule.invisibleCharacters.contains($0)
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}) else {
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continue
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}
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// Find all invisible characters and their positions
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var utf8Offset = 0
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for scalar in text.unicodeScalars {
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if InvisibleCharactersRule.invisibleCharacters.contains(scalar) {
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// Calculate absolute position of the invisible character
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let invisibleCharPosition = stringSegment.content.positionAfterSkippingLeadingTrivia
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.advanced(by: utf8Offset)
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let charName = characterName(for: scalar)
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let reason = "String literal should not contain invisible character: \(charName)"
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violations.append(
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ReasonedRuleViolation(
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position: invisibleCharPosition,
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reason: reason
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)
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)
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}
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utf8Offset += String(scalar).utf8.count
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}
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}
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}
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private func characterName(for scalar: Unicode.Scalar) -> String {
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switch scalar {
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case "\u{200B}":
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return "U+200B (zero-width space)"
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case "\u{FEFF}":
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return "U+FEFF (zero-width no-break space)"
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default:
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return "U+\(String(scalar.value, radix: 16, uppercase: true))"
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}
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}
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}
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}

‎Tests/GeneratedTests/GeneratedTests_04.swift‎

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@@ -115,6 +115,12 @@ final class InvalidSwiftLintCommandRuleGeneratedTests: SwiftLintTestCase {
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}
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}
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final class InvisibleCharactersRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(InvisibleCharactersRule.description)
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}
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}
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final class IsDisjointRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(IsDisjointRule.description)
@@ -150,9 +156,3 @@ final class LegacyCGGeometryFunctionsRuleGeneratedTests: SwiftLintTestCase {
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verifyRule(LegacyCGGeometryFunctionsRule.description)
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}
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}
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final class LegacyConstantRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(LegacyConstantRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_05.swift‎

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@@ -7,6 +7,12 @@
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@testable import SwiftLintCore
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import TestHelpers
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final class LegacyConstantRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(LegacyConstantRule.description)
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}
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}
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final class LegacyConstructorRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(LegacyConstructorRule.description)
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verifyRule(NSLocalizedStringRequireBundleRule.description)
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}
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}
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final class NSNumberInitAsFunctionReferenceRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(NSNumberInitAsFunctionReferenceRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_06.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class NSNumberInitAsFunctionReferenceRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(NSNumberInitAsFunctionReferenceRule.description)
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}
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}
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final class NSObjectPreferIsEqualRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(NSObjectPreferIsEqualRule.description)
@@ -150,9 +156,3 @@ final class PeriodSpacingRuleGeneratedTests: SwiftLintTestCase {
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verifyRule(PeriodSpacingRule.description)
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}
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}
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154-
final class PreferAssetSymbolsRuleGeneratedTests: SwiftLintTestCase {
155-
func testWithDefaultConfiguration() {
156-
verifyRule(PreferAssetSymbolsRule.description)
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}
158-
}

‎Tests/GeneratedTests/GeneratedTests_07.swift‎

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@@ -7,6 +7,12 @@
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@testable import SwiftLintCore
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import TestHelpers
99

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final class PreferAssetSymbolsRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(PreferAssetSymbolsRule.description)
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}
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}
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1016
final class PreferConditionListRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(PreferConditionListRule.description)
@@ -150,9 +156,3 @@ final class RedundantDiscardableLetRuleGeneratedTests: SwiftLintTestCase {
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verifyRule(RedundantDiscardableLetRule.description)
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}
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}
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final class RedundantNilCoalescingRuleGeneratedTests: SwiftLintTestCase {
155-
func testWithDefaultConfiguration() {
156-
verifyRule(RedundantNilCoalescingRule.description)
157-
}
158-
}

‎Tests/GeneratedTests/GeneratedTests_08.swift‎

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@@ -7,6 +7,12 @@
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@testable import SwiftLintCore
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import TestHelpers
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final class RedundantNilCoalescingRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(RedundantNilCoalescingRule.description)
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}
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}
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1016
final class RedundantObjcAttributeRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(RedundantObjcAttributeRule.description)
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verifyRule(StrictFilePrivateRule.description)
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}
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}
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154-
final class StrongIBOutletRuleGeneratedTests: SwiftLintTestCase {
155-
func testWithDefaultConfiguration() {
156-
verifyRule(StrongIBOutletRule.description)
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}
158-
}

‎Tests/GeneratedTests/GeneratedTests_09.swift‎

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@testable import SwiftLintCore
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import TestHelpers
99

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final class StrongIBOutletRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(StrongIBOutletRule.description)
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}
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}
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1016
final class SuperfluousElseRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(SuperfluousElseRule.description)
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verifyRule(UnneededSynthesizedInitializerRule.description)
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}
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}
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154-
final class UnneededThrowsRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(UnneededThrowsRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_10.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class UnneededThrowsRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(UnneededThrowsRule.description)
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}
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}
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1016
final class UnownedVariableCaptureRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(UnownedVariableCaptureRule.description)

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