From 73e6ba3067c831abde96a449385d0f0a610ef2a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Danny=20M=C3=B6sch?= <danny.moesch@icloud.com>
Date: Sun, 15 Oct 2023 12:43:43 +0200
Subject: [PATCH] Add parentheses to corrected opaque and existential optionals
 (#5278)

---
 CHANGELOG.md                                         |  5 +++++
 .../Rules/Idiomatic/SyntacticSugarRule.swift         | 12 ++++++++++++
 .../Rules/Idiomatic/SyntacticSugarRuleExamples.swift |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd247e5450..f4db4eefe2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,11 @@
 
 #### Bug Fixes
 
+* Fix invalid corrections for opaque and existential optionals in 
+  `syntactic_sugar` rule.  
+  [SimplyDanny](https://github.com/SimplyDanny)
+  [#5277](https://github.com/realm/SwiftLint/issues/5277)
+
 * Fix false positive in `unused_import` rule that triggered on 
   `@_exported` imports which could break downstream modules if removed.  
   [jszumski](https://github.com/jszumski)
diff --git a/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRule.swift b/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRule.swift
index 9bcd2f7e52..b398598357 100644
--- a/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRule.swift
+++ b/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRule.swift
@@ -300,6 +300,10 @@ private struct CorrectingContext<R: Rule> {
             correctViolations(violationsBeforeComma)
             replaceCharacters(in: leftRange, with: "[")
 
+        case .optional where typeIsOpaqueOrExistential(correction: correction):
+            replaceCharacters(in: rightRange, with: ")?")
+            correctViolations(violation.children)
+            replaceCharacters(in: leftRange, with: "(")
         case .optional:
             replaceCharacters(in: rightRange, with: "?")
             correctViolations(violation.children)
@@ -310,6 +314,14 @@ private struct CorrectingContext<R: Rule> {
         corrections.append(Correction(ruleDescription: type(of: rule).description, location: location))
     }
 
+    private func typeIsOpaqueOrExistential(correction: SyntacticSugarRuleViolation.Correction) -> Bool {
+        if let innerTypeRange = file.stringView.NSRange(start: correction.leftEnd, end: correction.rightStart) {
+            let innerTypeString = file.stringView.substring(with: innerTypeRange)
+            return innerTypeString.contains("any ") || innerTypeString.contains("some ")
+        }
+        return false
+    }
+
     private mutating func replaceCharacters(in range: NSRange, with replacement: String) {
         contents = contents.bridge().replacingCharacters(in: range, with: replacement)
     }
diff --git a/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRuleExamples.swift b/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRuleExamples.swift
index 85f73eb2be..2da01b60ca 100644
--- a/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRuleExamples.swift
+++ b/Source/SwiftLintBuiltInRules/Rules/Idiomatic/SyntacticSugarRuleExamples.swift
@@ -71,6 +71,8 @@ internal enum SyntacticSugarRuleExamples {
         Example("let x: Dictionary<Int, String>"): Example("let x: [Int: String]"),
         Example("let x: Optional<Int>"): Example("let x: Int?"),
         Example("let x: Optional< Int >"): Example("let x: Int?"),
+        Example("func f() -> Optional<any Foo> {}"): Example("func f() -> (any Foo)? {}"),
+        Example("func f() -> Optional<some Foo> {}"): Example("func f() -> (some Foo)? {}"),
 
         Example("let x: Dictionary<Int , String>"): Example("let x: [Int: String]"),
         Example("let x: Swift.Optional<String>"): Example("let x: String?"),