Fix adding @escaping keyword for closures in explicit init

Author: alschmut

Sources/BuildableClient/main.swift

@@ -2,7 +2,7 @@ import Buildable
 import Foundation
 
 @Buildable
-struct MyObject {
+public struct MyObject {
     let m01: String
     let m02: Int
     let m03: Int8
@@ -32,9 +32,12 @@ struct MyObject {
     let m27: [String: String]
     var m28: String
     let m29: () -> Void
-    let m30: (String) -> Void
-    let m31: (String, Int) -> Void
-    let m32: (String, Int) -> String
+    let m30: (() -> Void)?
+    let m31: (() -> Void)!
+    let m32: (String) -> Void
+    let m33: ((String) -> Void)?
+    let m34: (String, Int) -> Void
+    let m35: (String, Int) -> String
     var myEnum: MyEnum
 }
 

Sources/BuildableMacro/Utils/AccessLevel/InitParameter.swift

@@ -13,4 +13,17 @@ struct InitParameter: Identifiable {
     let identifier: TokenSyntax
     let type: TypeSyntax
     let value: TokenSyntax?
+    
+    var typeForExplicitInit: any TypeSyntaxProtocol {
+        if type.as(FunctionTypeSyntax.self) != nil {
+            return AttributedTypeSyntax(
+                specifiers: TypeSpecifierListSyntax {
+                    SimpleTypeSpecifierSyntax(specifier: .identifier("@escaping"))
+                },
+                baseType: type
+            )
+        } else {
+            return type
+        }
+    }
 }

Sources/BuildableMacro/Utils/AccessLevel/MakeExplicitInit.swift

@@ -18,7 +18,7 @@ func makeExplicitInit(parameters: [InitParameter], accessLevel: AccessLevel) ->
                         FunctionParameterSyntax(
                             leadingTrivia: .newline,
                             firstName: parameter.identifier,
-                            type: parameter.type,
+                            type: parameter.typeForExplicitInit,
                             defaultValue: InitializerClauseSyntax(value: getDefaultValue(from: parameter)),
                             trailingTrivia: parameter.id == parameters.last?.id ? .newline : nil
                         )

Tests/BuildableMacroTests/BuildableStructTests.swift

@@ -621,4 +621,63 @@ class BuildableStructTests: XCTestCase {
             macros: testMacros
         )
     }
+    
+    func test_should_add_escaping_keyword_for_closure_in_public_init() {
+        assertMacroExpansion(
+            """
+            @Buildable
+            public struct MyObject {
+                public let m1: () -> Void
+                public let m2: (String) -> Int
+                public let m3: (() -> Void)?
+                public let m4: (() -> Void)!
+            }
+            """,
+            expandedSource: """
+
+            public struct MyObject {
+                public let m1: () -> Void
+                public let m2: (String) -> Int
+                public let m3: (() -> Void)?
+                public let m4: (() -> Void)!
+            }
+
+            public struct MyObjectBuilder {
+                public var m1: () -> Void = {
+                }
+                public var m2: (String) -> Int = { _ in
+                    return 0
+                }
+                public var m3: (() -> Void)?
+                public var m4: (() -> Void)!
+            
+                public init(
+                    m1: @escaping () -> Void = {
+                    },
+                    m2: @escaping (String) -> Int = { _ in
+                        return 0
+                    },
+                    m3: (() -> Void)? = nil,
+                    m4: (() -> Void)! = nil
+                ) {
+                    self.m1 = m1
+                    self.m2 = m2
+                    self.m3 = m3
+                    self.m4 = m4
+                }
+
+                public func build() -> MyObject {
+                    return MyObject(
+                        m1: m1,
+                        m2: m2,
+                        m3: m3,
+                        m4: m4
+                    )
+                }
+            }
+
+            """,
+            macros: testMacros
+        )
+    }
 }