From 94c6009fc4077d69788c089a049ddb38113c4d28 Mon Sep 17 00:00:00 2001
From: Marcelo Fabri <me@marcelofabri.com>
Date: Thu, 4 Jul 2019 22:23:38 -0700
Subject: [PATCH] Fix false positive in `function_default_parameter_at_end`

Fixes #2788
---
 CHANGELOG.md                                  |  5 ++++
 Rules.md                                      |  5 ++++
 .../FunctionDefaultParameterAtEndRule.swift   | 23 +++++++++++++++----
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89349c1562..a898c195b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,11 @@
   [Marcelo Fabri](https://github.com/marcelofabri)
   [#2792](https://github.com/realm/SwiftLint/issues/2792)
 
+* Fix false positive in `function_default_parameter_at_end` rule when using
+  a closure parameter with default value.  
+  [Marcelo Fabri](https://github.com/marcelofabri)
+  [#2788](https://github.com/realm/SwiftLint/issues/2788)
+
 ## 0.33.0: Worldwide Dryers Conference
 
 #### Breaking
diff --git a/Rules.md b/Rules.md
index bb246b85c1..184cde8794 100644
--- a/Rules.md
+++ b/Rules.md
@@ -8399,6 +8399,11 @@ func foo(a: Int, b: CGFloat = 0) {
 }
 ```
 
+```swift
+func foo(a: String, b: String? = nil,
+         c: String? = nil, d: @escaping AlertActionHandler = { _ in }) {}
+```
+
 </details>
 <details>
 <summary>Triggering Examples</summary>
diff --git a/Source/SwiftLintFramework/Rules/Idiomatic/FunctionDefaultParameterAtEndRule.swift b/Source/SwiftLintFramework/Rules/Idiomatic/FunctionDefaultParameterAtEndRule.swift
index 2efba2490b..fd5cccf6d3 100644
--- a/Source/SwiftLintFramework/Rules/Idiomatic/FunctionDefaultParameterAtEndRule.swift
+++ b/Source/SwiftLintFramework/Rules/Idiomatic/FunctionDefaultParameterAtEndRule.swift
@@ -26,6 +26,10 @@ public struct FunctionDefaultParameterAtEndRule: ASTRule, ConfigurationProviderR
             func foo(a: Int, b: CGFloat = 0) {
               let block = { (error: Error?) in }
             }
+            """,
+            """
+            func foo(a: String, b: String? = nil,
+                     c: String? = nil, d: @escaping AlertActionHandler = { _ in }) {}
             """
         ],
         triggeringExamples: [
@@ -43,13 +47,22 @@ public struct FunctionDefaultParameterAtEndRule: ASTRule, ConfigurationProviderR
         }
 
         let isNotClosure = { !self.isClosureParameter(dictionary: $0) }
-        let params = dictionary.enclosedVarParameters.filter(isNotClosure).filter { param in
-            guard let paramOffset = param.offset else {
-                return false
+        let params = dictionary.substructure
+            .flatMap { subDict -> [[String: SourceKitRepresentable]] in
+                guard subDict.kind.flatMap(SwiftDeclarationKind.init) == .varParameter else {
+                    return []
+                }
+
+                return [subDict]
             }
+            .filter(isNotClosure)
+            .filter { param in
+                guard let paramOffset = param.offset else {
+                    return false
+                }
 
-            return paramOffset < bodyOffset
-        }
+                return paramOffset < bodyOffset
+            }
 
         guard !params.isEmpty else {
             return []