Ensure that conversions are defined for lambdas defined in struct

In the case of Swift language, when lambda was defined in
a structure, then the code could not compile because of
missing conversion functions. Interestingly, that was not
the case for classes.

After investigation it turned out, that the root cause is
related to missing inclusion of SwiftLambdaConversion
template in SwiftStructConversion.

This change:
 - adds missing inclusion of lambda conversions in the
   mentioned template (SwiftStructConversion.mustache)
 - implements functional tests for Swift to check that
   the fix works as expected
 - implements functional tests for Dart and Android to
   also cover the tested case in these technologies
 - updates the reference files for smoke tests related
   to definition of nested fields in structs

Signed-off-by: Patryk Wrobel <[email protected]>

functional-tests/functional/android/src/test/java/com/here/android/test/LambdasTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016-2019 HERE Europe B.V.
+ * Copyright (C) 2016-2024 HERE Europe B.V.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -160,4 +160,12 @@ public void callJavaOverloadedLambdaInCpp() {
 
     assertEquals("42", result);
   }
+
+  @Test
+  public void callJavaLambdaFromCppForLambdaDefinedInStruct() {
+    StructWithLambda.LambdaCallback callback = (String arg) -> arg;
+    String result = StructWithLambda.invokeCallback(callback);
+
+    assertEquals("some callback argument", result);
+  }
 }

functional-tests/functional/dart/test/Lambdas_test.dart

@@ -1,5 +1,5 @@
 // -------------------------------------------------------------------------------------------------
-// Copyright (C) 2016-2020 HERE Europe B.V.
+// Copyright (C) 2016-2024 HERE Europe B.V.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -130,4 +130,11 @@ void main() {
 
     expect(result, isNull);
   });
+  _testSuite.test("Call Dart lambda in C++ for lambda defined in struct", () {
+    final callback = (String? arg) => arg;
+
+    final result = StructWithLambda.invokeCallback(callback);
+
+    expect(result!, "some callback argument");
+  });
 }

functional-tests/functional/input/lime/Lambdas.lime

@@ -1,4 +1,4 @@
-# Copyright (C) 2016-2019 HERE Europe B.V.
+# Copyright (C) 2016-2024 HERE Europe B.V.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -61,6 +61,12 @@ class LambdasDeclarationOrder {
     }
 }
 
+struct StructWithLambda {
+    lambda LambdaCallback = (String?) -> String?
+
+    static fun invoke_callback(callback: LambdaCallback?): String?
+}
+
 interface LambdasInterface {
     lambda TakeScreenshotCallback = (Blob?) -> Void
 

functional-tests/functional/input/src/cpp/Lambdas.cpp

@@ -1,5 +1,5 @@
 // -------------------------------------------------------------------------------------------------
-// Copyright (C) 2016-2019 HERE Europe B.V.
+// Copyright (C) 2016-2024 HERE Europe B.V.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -20,8 +20,11 @@
 
 #include "test/CallOverloadedLambda.h"
 #include "test/ClassWithInternalLambda.h"
+#include "test/StructWithLambda.h"
 #include "test/Lambdas.h"
 
+#include <functional>
+
 namespace test
 {
 
@@ -152,4 +155,13 @@ CallOverloadedLambda::invoke_overloaded_lambda(const OverloadedLambda& lambda,
     return lambda(value);
 }
 
+std::optional<std::string>
+StructWithLambda::invoke_callback(const std::optional<LambdaCallback>& callback) {
+    if (callback) {
+        return std::invoke(*callback, "some callback argument");
+    }
+
+    return {};
+}
+
 }

functional-tests/functional/swift/Tests/LambdasTests.swift

@@ -1,5 +1,5 @@
 // -------------------------------------------------------------------------------------------------
-// Copyright (C) 2016-2019 HERE Europe B.V.
+// Copyright (C) 2016-2024 HERE Europe B.V.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -128,6 +128,13 @@ class LambdasTests: XCTestCase {
         XCTAssertNil(result)
     }
 
+    func testCallingSwiftLambdaFromCppForLambdaDefinedInStruct() {
+        let callback = { (arg: String?) in return arg }
+        let result = StructWithLambda.invokeCallback(callback: callback)
+
+        XCTAssertEqual(result, "some callback argument");
+    }
+
     static var allTests = [
         ("testCppLambdaInSwift", testCppLambdaInSwift),
         ("testSwiftLambdaInCpp", testSwiftLambdaInCpp),
@@ -143,6 +150,7 @@ class LambdasTests: XCTestCase {
         ("testCppNullableLambdaInSwiftWithValue", testCppNullableLambdaInSwiftWithValue),
         ("testCppNullableLambdaInSwiftWithNil", testCppNullableLambdaInSwiftWithNil),
         ("testSwiftNullableLambdaInCppWithValue", testSwiftNullableLambdaInCppWithValue),
-        ("testSwiftNullableLambdaInCppWithNil", testSwiftNullableLambdaInCppWithNil)
+        ("testSwiftNullableLambdaInCppWithNil", testSwiftNullableLambdaInCppWithNil),
+        ("testCallingSwiftLambdaFromCppForLambdaDefinedInStruct", testCallingSwiftLambdaFromCppForLambdaDefinedInStruct)
     ]
 }

gluecodium/src/main/resources/templates/swift/SwiftStructConversion.mustache

@@ -1,6 +1,6 @@
 {{!!
   !
-  ! Copyright (C) 2016-2019 HERE Europe B.V.
+  ! Copyright (C) 2016-2024 HERE Europe B.V.
   !
   ! Licensed under the Apache License, Version 2.0 (the "License");
   ! you may not use this file except in compliance with the License.
@@ -95,6 +95,9 @@ Optionals
 {{#structs}}
 {{>swift/SwiftStructConversion}}{{!!
 }}{{/structs}}
+{{#lambdas}}
+{{>swift/SwiftLambdaConversion}}{{!!
+}}{{/lambdas}}
 {{#enumerations}}
 {{>swift/SwiftEnumConversion}}{{!!
 }}{{/enumerations}}