Refactor to more closely match starter project from Xcode 16.2

Author: andrewheard

FirebaseAI/Sources/Types/Public/Generable/MacroDeclarations.swift

@@ -0,0 +1,23 @@
+// Copyright 2025 Google LLC
+//
+// 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
+//
+//      http://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.
+
+/// A macro that produces both a value and a string containing the
+/// source code that generated the value. For example,
+///
+///     #stringify(x + y)
+///
+/// produces a tuple `(x + y, "x + y")`.
+@freestanding(expression)
+public macro stringify<T>(_ value: T) -> (T, String) =
+  #externalMacro(module: "FirebaseAILogicMacros", type: "StringifyMacro")

FirebaseAI/Tests/Unit/Macros/GenerableMacroTests.swift

@@ -23,9 +23,15 @@
   import XCTest
 
   final class GenerableMacroTests: XCTestCase {
-    let testMacros: [String: Macro.Type] = [
-      "stringify": StringifyMacro.self,
-    ]
+    #if swift(>=6.2)
+      nonisolated(unsafe) static let testMacros: [String: Macro.Type] = [
+        "stringify": StringifyMacro.self,
+      ]
+    #else
+      static let testMacros: [String: Macro.Type] = [
+        "stringify": StringifyMacro.self,
+      ]
+    #endif // swift(>=6.2)
 
     func testMacro() throws {
       assertMacroExpansion(
@@ -35,7 +41,7 @@
         expandedSource: """
         (a + b, "a + b")
         """,
-        macros: testMacros
+        macros: GenerableMacroTests.testMacros
       )
     }
 
@@ -47,7 +53,7 @@
         expandedSource: #"""
         ("Hello, \(name)", #""Hello, \(name)""#)
         """#,
-        macros: testMacros
+        macros: GenerableMacroTests.testMacros
       )
     }
   }

Package.swift

@@ -177,7 +177,7 @@ let package = Package(
     ),
     .package(url: "https://github.com/google/app-check.git",
              "11.0.1" ..< "12.0.0"),
-    .package(url: "https://github.com/swiftlang/swift-syntax.git", "600.0.1" ..< "601.0.0"),
+    .package(url: "https://github.com/swiftlang/swift-syntax.git", from: "600.0.0-latest"),
   ],
   targets: [
     .target(
@@ -203,8 +203,6 @@ let package = Package(
     .macro(
       name: "FirebaseAILogicMacros",
       dependencies: [
-        .product(name: "SwiftSyntax", package: "swift-syntax"),
-        .product(name: "SwiftSyntaxMacroExpansion", package: "swift-syntax"),
         .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
         .product(name: "SwiftCompilerPlugin", package: "swift-syntax"),
       ],
@@ -215,23 +213,13 @@ let package = Package(
       dependencies: [
         "FirebaseAILogic",
         "FirebaseStorage",
-        .target(
-          name: "FirebaseAILogicMacros",
-          condition: .when(platforms: [.macOS])
-        ),
-        .product(
-          name: "SwiftSyntaxMacrosTestSupport",
-          package: "swift-syntax",
-          condition: .when(platforms: [.macOS])
-        ),
+        "FirebaseAILogicMacros",
+        .product(name: "SwiftSyntaxMacrosTestSupport", package: "swift-syntax"),
       ],
       path: "FirebaseAI/Tests/Unit",
       resources: [
         .copy("vertexai-sdk-test-data/mock-responses"),
         .process("Resources"),
-      ],
-      cSettings: [
-        .headerSearchPath("../../../"),
       ]
     ),
     .target(