Merge pull request #3151 from square/cycle_bug

[swift] Fix not marking oneof field as `@Indirect` when detecting a cycle

wire-runtime-swift/src/main/swift/propertyWrappers/Indirect.swift

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 @propertyWrapper
-public enum Indirect<Value : ProtoCodable> {
+public enum Indirect<Value> {
     // Dedicated .none case for nil means the runtime size of this case is equal to a single
     // pointer rather than the two for the .some case.
     case none

wire-runtime-swift/src/test/proto/cycles.proto

@@ -37,3 +37,14 @@ message C {
 message D {
   optional A a = 1;
 }
+
+message F {
+  oneof action {
+    G g = 1;
+    string s = 2;
+  }
+}
+
+message G {
+  optional F f = 1;
+}

wire-runtime-swift/src/test/swift/CyclesTests.swift

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2024 Square, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import Foundation
+import Wire
+import XCTest
+
+final class CyclesTests: XCTestCase {
+    func testOneOfFieldCycle() throws {
+        let f = F {
+            $0.action = .g(G())
+        }
+
+        let encoder = ProtoEncoder()
+        let data = try encoder.encode(f)
+
+        let decoder = ProtoDecoder()
+        let decodedMessage = try decoder.decode(F.self, from: data)
+
+        XCTAssertEqual(decodedMessage, f)
+    }
+}

wire-swift-generator/src/main/java/com/squareup/wire/swift/SwiftGenerator.kt

@@ -1363,6 +1363,9 @@ class SwiftGenerator private constructor(
             if (oneOf.documentation.isNotBlank()) {
               addDoc("%N\n", oneOf.documentation.sanitizeDoc())
             }
+            if (oneOf.fields.any { oneOfField -> isIndirect(type, oneOfField) }) {
+              addAttribute(AttributeSpec.builder(indirect).build())
+            }
           }
           .build(),
       )