From 537dec1d37852c9b13f089bc2517b1a4ff693b2a Mon Sep 17 00:00:00 2001
From: Marcelo Fabri <me@marcelofabri.com>
Date: Tue, 9 Apr 2019 10:43:57 -0700
Subject: [PATCH] Fix false positives on `explicit_acl` and
 `explicit_top_level_acl`

Fixes #2705
---
 CHANGELOG.md                                        |  5 +++++
 Rules.md                                            |  8 ++++++++
 .../Rules/Idiomatic/ExplicitACLRule.swift           | 12 +++++++++++-
 .../Rules/Idiomatic/ExplicitTopLevelACLRule.swift   | 13 ++++++++++++-
 4 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ae643b861..ccdd7624b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -72,6 +72,11 @@
   [Keith Smiley](https://github.com/keith)
   [#2703](https://github.com/realm/SwiftLint/issues/2703)
 
+* Fix false positives on `explicit_acl` and `explicit_top_level_acl` rules when
+  declaring extensions that add protocol conformances with Swift 5.  
+  [Marcelo Fabri](https://github.com/marcelofabri)
+  [#2705](https://github.com/realm/SwiftLint/issues/2705)
+
 ## 0.31.0: Busy Laundromat
 
 #### Breaking
diff --git a/Rules.md b/Rules.md
index d157789f1a..b6137b4047 100644
--- a/Rules.md
+++ b/Rules.md
@@ -5728,6 +5728,10 @@ internal protocol A {
 internal class A { deinit {} }
 ```
 
+```swift
+extension A: Equatable {}
+```
+
 </details>
 <details>
 <summary>Triggering Examples</summary>
@@ -6034,6 +6038,10 @@ internal func a() {}
 
 ```
 
+```swift
+extension A: Equatable {}
+```
+
 </details>
 <details>
 <summary>Triggering Examples</summary>
diff --git a/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitACLRule.swift b/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitACLRule.swift
index 19434ed9ea..329dacb2dc 100644
--- a/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitACLRule.swift
+++ b/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitACLRule.swift
@@ -39,7 +39,8 @@ public struct ExplicitACLRule: OptInRule, ConfigurationProviderRule, AutomaticTe
               var b: Int
             }
             """,
-            "internal class A { deinit {} }"
+            "internal class A { deinit {} }",
+            "extension A: Equatable {}"
         ],
         triggeringExamples: [
             "enum A {}\n",
@@ -60,11 +61,20 @@ public struct ExplicitACLRule: OptInRule, ConfigurationProviderRule, AutomaticTe
 
     private func offsetOfElements(from elements: [SourceKittenElement], in file: File,
                                   thatAreNotInRanges ranges: [NSRange]) -> [Int] {
+        let extensionKinds: Set<SwiftDeclarationKind> = [.extension, .extensionClass, .extensionEnum,
+                                                         .extensionProtocol, .extensionStruct]
+
         return elements.compactMap { element in
             guard let typeOffset = element.offset else {
                 return nil
             }
 
+            guard let kind = element.kind.flatMap(SwiftDeclarationKind.init(rawValue:)),
+                case let isConformanceExtension = extensionKinds.contains(kind) && !element.inheritedTypes.isEmpty,
+                !isConformanceExtension else {
+                    return nil
+            }
+
             // find the last "internal" token before the type
             guard let previousInternalByteRange = lastInternalByteRange(before: typeOffset, in: ranges) else {
                 return typeOffset
diff --git a/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitTopLevelACLRule.swift b/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitTopLevelACLRule.swift
index 81d78d18cd..7159e14646 100644
--- a/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitTopLevelACLRule.swift
+++ b/Source/SwiftLintFramework/Rules/Idiomatic/ExplicitTopLevelACLRule.swift
@@ -18,7 +18,8 @@ public struct ExplicitTopLevelACLRule: OptInRule, ConfigurationProviderRule, Aut
             "internal enum A {\n enum B {}\n}",
             "internal final class Foo {}",
             "internal\nclass Foo {}",
-            "internal func a() {}\n"
+            "internal func a() {}\n",
+            "extension A: Equatable {}"
         ],
         triggeringExamples: [
             "enum A {}\n",
@@ -30,8 +31,18 @@ public struct ExplicitTopLevelACLRule: OptInRule, ConfigurationProviderRule, Aut
     )
 
     public func validate(file: File) -> [StyleViolation] {
+        let extensionKinds: Set<SwiftDeclarationKind> = [.extension, .extensionClass, .extensionEnum,
+                                                         .extensionProtocol, .extensionStruct]
+
         // find all top-level types marked as internal (either explictly or implictly)
         let internalTypesOffsets = file.structure.dictionary.substructure.compactMap { element -> Int? in
+            // ignore extensions that declare protocol conformance
+            guard let kind = element.kind.flatMap(SwiftDeclarationKind.init(rawValue:)),
+                case let isConformanceExtension = extensionKinds.contains(kind) && !element.inheritedTypes.isEmpty,
+                !isConformanceExtension else {
+                    return nil
+            }
+
             if element.accessibility.flatMap(AccessControlLevel.init(identifier:)) == .internal {
                 return element.offset
             }