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Add new invisible_characters rule (#6424)
Co-authored-by: Miniakhmetov Eduard <eminiakhmetov@sportmasterlab.net>
1 parent 0316649 commit c40896d

13 files changed

Lines changed: 285 additions & 44 deletions

‎CHANGELOG.md‎

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[nadeemnali](https://github.com/nadeemnali)
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[#6359](https://github.com/realm/SwiftLint/issues/6359)
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* Add new default `invisible_character` rule that detects invisible characters
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like zero-width space (U+200B), zero-width non-joiner (U+200C),
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and FEFF formatting character (U+FEFF) in string literals, which can cause hard-to-debug issues.
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[kapitoshka438](https://github.com/kapitoshka438)
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[#6045](https://github.com/realm/SwiftLint/issues/6045)
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### Bug Fixes
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* Add an `ignore_attributes` option to `implicit_optional_initialization` so

‎Source/SwiftLintBuiltInRules/Models/BuiltInRules.swift‎

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@@ -96,6 +96,7 @@ 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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InvisibleCharacterRule.self,
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IsDisjointRule.self,
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JoinedDefaultParameterRule.self,
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LargeTupleRule.self,

‎Source/SwiftLintBuiltInRules/Rules/Lint/InvisibleCharacterRule.swift‎

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import SwiftSyntax
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@SwiftSyntaxRule(correctable: true)
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struct InvisibleCharacterRule: Rule {
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var configuration = InvisibleCharacterConfiguration()
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// swiftlint:disable invisible_character
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static let description = RuleDescription(
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identifier: "invisible_character",
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name: "Invisible Character",
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description: """
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Disallows invisible characters like zero-width space (U+200B), \
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zero-width non-joiner (U+200C), 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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""",
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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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Example(#"let s = "Hello↓​World" // U+200B zero-width space"#),
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Example(#"let s = "Hello↓‌World" // U+200C zero-width non-joiner"#),
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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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// U+200B in multiline string
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let multiline = \"\"\"
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Hello↓​World
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\"\"\"
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"""),
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Example(#"let s = "Test↓​String↓Here" // Multiple invisible characters"#),
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Example(#"let s = "Hel↓‌lo" + "World" // string concatenation with U+200C"#),
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Example(#"let s = "Hel↓‌lo \(name)" // U+200C in interpolated string"#),
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Example("""
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//
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// additional_code_points: ["00AD"]
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//
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let s = "Hello↓­World"
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""",
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configuration: [
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"additional_code_points": ["00AD"],
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]
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),
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Example("""
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//
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// additional_code_points: ["200D"]
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//
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let s = "Hello↓‍World"
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""",
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configuration: [
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"additional_code_points": ["200D"],
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]
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),
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],
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corrections: [
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Example(#"let s = "Hello​World""#): Example(#"let s = "HelloWorld""#),
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Example(#"let s = "Hello‌World""#): Example(#"let s = "HelloWorld""#),
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Example(#"let s = "HelloWorld""#): Example(#"let s = "HelloWorld""#),
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Example(#"let url = "https://example​.com""#): Example(#"let url = "https://example.com""#),
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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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"""): Example("""
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let multiline = \"\"\"
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HelloWorld
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\"\"\"
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"""),
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Example(#"let s = "Test​StringHere""#): Example(#"let s = "TestStringHere""#),
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Example(#"let s = "Hel‌lo" + "World""#): Example(#"let s = "Hello" + "World""#),
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Example(#"let s = "Hel‌lo \(name)""#): Example(#"let s = "Hello \(name)""#),
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Example(
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#"let s = "Hello­World""#,
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configuration: [
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"additional_code_points": ["00AD"],
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]
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): Example(
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#"let s = "HelloWorld""#,
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configuration: [
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"additional_code_points": ["00AD"],
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]
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),
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Example(
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#"let s = "Hello‍World""#,
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configuration: [
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"additional_code_points": ["200D"],
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]
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): Example(
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#"let s = "HelloWorld""#,
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configuration: [
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"additional_code_points": ["200D"],
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]
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),
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]
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)
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// swiftlint:enable invisible_character
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}
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private extension InvisibleCharacterRule {
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final class Visitor: ViolationsSyntaxVisitor<ConfigurationType> {
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override func visitPost(_ node: StringLiteralExprSyntax) {
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let violatingCharacters = configuration.violatingCharacters
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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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let scalars = text.unicodeScalars
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guard scalars.contains(where: { violatingCharacters.contains($0) }) else {
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continue
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}
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var utf8Offset = 0
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for scalar in scalars {
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defer {
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utf8Offset += scalar.utf8.count
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}
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guard violatingCharacters.contains(scalar) else {
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continue
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}
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let characterName = InvisibleCharacterConfiguration.defaultCharacterDescriptions[scalar]
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?? scalar.escaped(asASCII: true)
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let position = stringSegment.content.positionAfterSkippingLeadingTrivia.advanced(by: utf8Offset)
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violations.append(
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ReasonedRuleViolation(
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position: position,
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reason: "String literal should not contain invisible character \(characterName)",
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correction: .init(
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start: position,
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end: position.advanced(by: scalar.utf8.count),
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replacement: ""
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)
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)
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)
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}
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}
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}
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}
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}

‎Source/SwiftLintBuiltInRules/Rules/RuleConfigurations/InvisibleCharacterConfiguration.swift‎

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import SwiftLintCore
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@AutoConfigParser
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struct InvisibleCharacterConfiguration: SeverityBasedRuleConfiguration {
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static let defaultCharacterDescriptions: [UnicodeScalar: String] = [
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"\u{200B}": "U+200B (zero-width space)",
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"\u{200C}": "U+200C (zero-width non-joiner)",
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"\u{FEFF}": "U+FEFF (zero-width no-break space)",
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]
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@ConfigurationElement(key: "severity")
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private(set) var severityConfiguration = SeverityConfiguration<Parent>.error
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@ConfigurationElement(
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key: "additional_code_points",
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postprocessor: {
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$0.formUnion(defaultCharacterDescriptions.keys)
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}
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)
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private(set) var violatingCharacters = Set<UnicodeScalar>()
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}
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extension UnicodeScalar: AcceptableByConfigurationElement {
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public init(fromAny value: Any, context ruleID: String) throws(Issue) {
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guard let hexCode = value as? String,
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let codePoint = UInt32(hexCode, radix: 16),
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let scalar = Self(codePoint) else {
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throw .invalidConfiguration(
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ruleID: ruleID,
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message: "\(value) is not a valid Unicode scalar code point."
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)
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}
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self = scalar
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}
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public func asOption() -> OptionType {
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.string(.init(value, radix: 16, uppercase: true))
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}
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}

‎Tests/GeneratedTests/GeneratedTests_04.swift‎

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@@ -121,6 +121,12 @@ final class InvalidSwiftLintCommandRuleGeneratedTests: SwiftLintTestCase {
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}
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}
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final class InvisibleCharacterRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(InvisibleCharacterRule.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)
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verifyRule(LeadingWhitespaceRule.description)
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}
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}
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final class LegacyCGGeometryFunctionsRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(LegacyCGGeometryFunctionsRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_05.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class LegacyCGGeometryFunctionsRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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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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verifyRule(NSLocalizedStringKeyRule.description)
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}
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}
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final class NSLocalizedStringRequireBundleRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(NSLocalizedStringRequireBundleRule.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 NSLocalizedStringRequireBundleRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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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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verifyRule(PatternMatchingKeywordsRule.description)
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}
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}
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final class PeriodSpacingRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(PeriodSpacingRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_07.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class PeriodSpacingRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(PeriodSpacingRule.description)
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}
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}
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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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verifyRule(ReduceIntoRule.description)
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}
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}
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final class RedundantDiscardableLetRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(RedundantDiscardableLetRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_08.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class RedundantDiscardableLetRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(RedundantDiscardableLetRule.description)
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}
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}
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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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verifyRule(StaticOverFinalClassRule.description)
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}
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}
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final class StrictFilePrivateRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(StrictFilePrivateRule.description)
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}
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}

‎Tests/GeneratedTests/GeneratedTests_09.swift‎

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@testable import SwiftLintCore
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import TestHelpers
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final class StrictFilePrivateRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(StrictFilePrivateRule.description)
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}
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}
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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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verifyRule(UnneededParenthesesInClosureArgumentRule.description)
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}
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}
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final class UnneededSynthesizedInitializerRuleGeneratedTests: SwiftLintTestCase {
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func testWithDefaultConfiguration() {
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verifyRule(UnneededSynthesizedInitializerRule.description)
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}
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}

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