Encode model in GenerateContentRequest only when needed

Sources/GoogleAI/CountTokensRequest.swift

@@ -17,7 +17,7 @@ import Foundation
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
 struct CountTokensRequest {
   let model: String
-  let contents: [ModelContent]
+  let generateContentRequest: GenerateContentRequest
   let options: RequestOptions
 }
 
@@ -42,7 +42,7 @@ public struct CountTokensResponse {
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
 extension CountTokensRequest: Encodable {
   enum CodingKeys: CodingKey {
-    case contents
+    case generateContentRequest
   }
 }
 

Sources/GoogleAI/GenerateContentRequest.swift

@@ -16,8 +16,11 @@ import Foundation
 
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
 struct GenerateContentRequest {
-  /// Model name.
+  // Model name.
   let model: String
+  // If true, the `model` field above is encoded in requests; currently only required when nested in
+  // a `CountTokensRequest`.
+  let isModelEncoded: Bool
   let contents: [ModelContent]
   let generationConfig: GenerationConfig?
   let safetySettings: [SafetySetting]?
@@ -31,13 +34,38 @@ struct GenerateContentRequest {
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
 extension GenerateContentRequest: Encodable {
   enum CodingKeys: String, CodingKey {
+    case model
     case contents
     case generationConfig
     case safetySettings
     case tools
     case toolConfig
     case systemInstruction
   }
+
+  func encode(to encoder: any Encoder) throws {
+    var container = encoder.container(keyedBy: CodingKeys.self)
+
+    if isModelEncoded {
+      try container.encode(model, forKey: .model)
+    }
+    try container.encode(contents, forKey: .contents)
+    if let generationConfig {
+      try container.encode(generationConfig, forKey: .generationConfig)
+    }
+    if let safetySettings {
+      try container.encode(safetySettings, forKey: .safetySettings)
+    }
+    if let tools {
+      try container.encode(tools, forKey: .tools)
+    }
+    if let toolConfig {
+      try container.encode(toolConfig, forKey: .toolConfig)
+    }
+    if let systemInstruction {
+      try container.encode(systemInstruction, forKey: .systemInstruction)
+    }
+  }
 }
 
 @available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)

Sources/GoogleAI/GenerativeModel.swift

@@ -175,15 +175,18 @@ public final class GenerativeModel {
     -> GenerateContentResponse {
     let response: GenerateContentResponse
     do {
-      let generateContentRequest = try GenerateContentRequest(model: modelResourceName,
-                                                              contents: content(),
-                                                              generationConfig: generationConfig,
-                                                              safetySettings: safetySettings,
-                                                              tools: tools,
-                                                              toolConfig: toolConfig,
-                                                              systemInstruction: systemInstruction,
-                                                              isStreaming: false,
-                                                              options: requestOptions)
+      let generateContentRequest = try GenerateContentRequest(
+        model: modelResourceName,
+        isModelEncoded: false,
+        contents: content(),
+        generationConfig: generationConfig,
+        safetySettings: safetySettings,
+        tools: tools,
+        toolConfig: toolConfig,
+        systemInstruction: systemInstruction,
+        isStreaming: false,
+        options: requestOptions
+      )
       response = try await generativeAIService.loadRequest(request: generateContentRequest)
     } catch {
       if let imageError = error as? ImageConversionError {
@@ -249,15 +252,18 @@ public final class GenerativeModel {
       }
     }
 
-    let generateContentRequest = GenerateContentRequest(model: modelResourceName,
-                                                        contents: evaluatedContent,
-                                                        generationConfig: generationConfig,
-                                                        safetySettings: safetySettings,
-                                                        tools: tools,
-                                                        toolConfig: toolConfig,
-                                                        systemInstruction: systemInstruction,
-                                                        isStreaming: true,
-                                                        options: requestOptions)
+    let generateContentRequest = GenerateContentRequest(
+      model: modelResourceName,
+      isModelEncoded: false,
+      contents: evaluatedContent,
+      generationConfig: generationConfig,
+      safetySettings: safetySettings,
+      tools: tools,
+      toolConfig: toolConfig,
+      systemInstruction: systemInstruction,
+      isStreaming: true,
+      options: requestOptions
+    )
 
     var responseIterator = generativeAIService.loadRequestStream(request: generateContentRequest)
       .makeAsyncIterator()
@@ -325,9 +331,19 @@ public final class GenerativeModel {
   public func countTokens(_ content: @autoclosure () throws -> [ModelContent]) async throws
     -> CountTokensResponse {
     do {
-      let countTokensRequest = try CountTokensRequest(
+      let generateContentRequest = try GenerateContentRequest(model: modelResourceName,
+                                                              isModelEncoded: true,
+                                                              contents: content(),
+                                                              generationConfig: generationConfig,
+                                                              safetySettings: safetySettings,
+                                                              tools: tools,
+                                                              toolConfig: toolConfig,
+                                                              systemInstruction: systemInstruction,
+                                                              isStreaming: false,
+                                                              options: requestOptions)
+      let countTokensRequest = CountTokensRequest(
         model: modelResourceName,
-        contents: content(),
+        generateContentRequest: generateContentRequest,
         options: requestOptions
       )
       return try await generativeAIService.loadRequest(request: countTokensRequest)

Tests/GoogleAITests/GenerateContentRequestTests.swift

@@ -0,0 +1,180 @@
+// Copyright 2024 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.
+
+import Foundation
+import XCTest
+
+@testable import GoogleGenerativeAI
+
+@available(iOS 15.0, macOS 11.0, macCatalyst 15.0, *)
+final class GenerateContentRequestTests: XCTestCase {
+  let encoder = JSONEncoder()
+  let role = "test-role"
+  let prompt = "test-prompt"
+  let modelName = "test-model-name"
+
+  override func setUp() {
+    encoder.outputFormatting = .init(
+      arrayLiteral: .prettyPrinted, .sortedKeys, .withoutEscapingSlashes
+    )
+  }
+
+  // MARK: GenerateContentRequest Encoding
+
+  func testEncodeRequest_allFieldsIncluded() throws {
+    let content = [ModelContent(role: role, parts: prompt)]
+    let request = GenerateContentRequest(
+      model: modelName,
+      isModelEncoded: true,
+      contents: content,
+      generationConfig: GenerationConfig(temperature: 0.5),
+      safetySettings: [SafetySetting(
+        harmCategory: .dangerousContent,
+        threshold: .blockLowAndAbove
+      )],
+      tools: [Tool(functionDeclarations: [FunctionDeclaration(
+        name: "test-function-name",
+        description: "test-function-description",
+        parameters: nil
+      )])],
+      toolConfig: ToolConfig(functionCallingConfig: FunctionCallingConfig(mode: .auto)),
+      systemInstruction: ModelContent(role: "system", parts: "test-system-instruction"),
+      isStreaming: false,
+      options: RequestOptions()
+    )
+
+    let jsonData = try encoder.encode(request)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+      "contents" : [
+        {
+          "parts" : [
+            {
+              "text" : "\(prompt)"
+            }
+          ],
+          "role" : "\(role)"
+        }
+      ],
+      "generationConfig" : {
+        "temperature" : 0.5
+      },
+      "model" : "\(modelName)",
+      "safetySettings" : [
+        {
+          "category" : "HARM_CATEGORY_DANGEROUS_CONTENT",
+          "threshold" : "BLOCK_LOW_AND_ABOVE"
+        }
+      ],
+      "systemInstruction" : {
+        "parts" : [
+          {
+            "text" : "test-system-instruction"
+          }
+        ],
+        "role" : "system"
+      },
+      "toolConfig" : {
+        "functionCallingConfig" : {
+          "mode" : "AUTO"
+        }
+      },
+      "tools" : [
+        {
+          "functionDeclarations" : [
+            {
+              "description" : "test-function-description",
+              "name" : "test-function-name",
+              "parameters" : {
+                "type" : "OBJECT"
+              }
+            }
+          ]
+        }
+      ]
+    }
+    """)
+  }
+
+  func testEncodeRequest_optionalFieldsOmitted_modelNameEncoded() throws {
+    let content = [ModelContent(role: role, parts: prompt)]
+    let request = GenerateContentRequest(
+      model: modelName,
+      isModelEncoded: true,
+      contents: content,
+      generationConfig: nil,
+      safetySettings: nil,
+      tools: nil,
+      toolConfig: nil,
+      systemInstruction: nil,
+      isStreaming: false,
+      options: RequestOptions()
+    )
+
+    let jsonData = try encoder.encode(request)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+      "contents" : [
+        {
+          "parts" : [
+            {
+              "text" : "\(prompt)"
+            }
+          ],
+          "role" : "\(role)"
+        }
+      ],
+      "model" : "\(modelName)"
+    }
+    """)
+  }
+
+  func testEncodeRequest_optionalFieldsOmitted_modelNameNotEncoded() throws {
+    let content = [ModelContent(role: role, parts: prompt)]
+    let request = GenerateContentRequest(
+      model: modelName,
+      isModelEncoded: false,
+      contents: content,
+      generationConfig: nil,
+      safetySettings: nil,
+      tools: nil,
+      toolConfig: nil,
+      systemInstruction: nil,
+      isStreaming: false,
+      options: RequestOptions()
+    )
+
+    let jsonData = try encoder.encode(request)
+
+    let json = try XCTUnwrap(String(data: jsonData, encoding: .utf8))
+    XCTAssertEqual(json, """
+    {
+      "contents" : [
+        {
+          "parts" : [
+            {
+              "text" : "\(prompt)"
+            }
+          ],
+          "role" : "\(role)"
+        }
+      ]
+    }
+    """)
+  }
+}