[Vertex AI] Log warning for unsupported model names (#14610)

Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>

Author: andrewheard

FirebaseVertexAI/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 11.11.0
+- [added] Emits a warning when attempting to use an incompatible model with
+  `GenerativeModel` or `ImagenModel`. (#14610)
+
 # 11.10.0
 - [feature] The Vertex AI SDK no longer requires `@preconcurrency` when imported in Swift 6.
 - [feature] The Vertex AI Sample App now includes an image generation example.

FirebaseVertexAI/Sources/GenerativeModel.swift

@@ -20,6 +20,9 @@ import Foundation
 /// content based on various input types.
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
 public final class GenerativeModel: Sendable {
+  /// Model name prefix to identify Gemini models.
+  static let geminiModelNamePrefix = "gemini-"
+
   /// The resource name of the model in the backend; has the format "models/model-name".
   let modelResourceName: String
 
@@ -71,6 +74,13 @@ public final class GenerativeModel: Sendable {
        systemInstruction: ModelContent? = nil,
        requestOptions: RequestOptions,
        urlSession: URLSession = .shared) {
+    if !name.starts(with: GenerativeModel.geminiModelNamePrefix) {
+      VertexLog.warning(code: .unsupportedGeminiModel, """
+      Unsupported Gemini model "\(name)"; see \
+      https://firebase.google.com/docs/vertex-ai/models for a list supported Gemini model names.
+      """)
+    }
+
     modelResourceName = name
     self.apiConfig = apiConfig
     generativeAIService = GenerativeAIService(

FirebaseVertexAI/Sources/Types/Public/Imagen/ImagenModel.swift

@@ -28,6 +28,9 @@ import Foundation
 /// could change in backwards-incompatible ways.
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
 public final class ImagenModel {
+  /// Model name prefix to identify Imagen models.
+  static let imagenModelNamePrefix = "imagen-"
+
   /// The resource name of the model in the backend; has the format "models/model-name".
   let modelResourceName: String
 
@@ -51,6 +54,13 @@ public final class ImagenModel {
        safetySettings: ImagenSafetySettings?,
        requestOptions: RequestOptions,
        urlSession: URLSession = .shared) {
+    if !name.starts(with: ImagenModel.imagenModelNamePrefix) {
+      VertexLog.warning(code: .unsupportedImagenModel, """
+      Unsupported Imagen model "\(name)"; see \
+      https://firebase.google.com/docs/vertex-ai/models for a list supported Imagen model names.
+      """)
+    }
+
     modelResourceName = name
     self.apiConfig = apiConfig
     generativeAIService = GenerativeAIService(

FirebaseVertexAI/Sources/VertexLog.swift

@@ -33,8 +33,10 @@ enum VertexLog {
 
     // Generative Model Configuration
     case generativeModelInitialized = 1000
+    case unsupportedGeminiModel = 1001
 
     // Imagen Model Configuration
+    case unsupportedImagenModel = 1200
     case imagenInvalidJPEGCompressionQuality = 1201
 
     // Network Errors