[Vertex AI] Add text-only generateContent and Chat snippets (#13926)

Author: andrewheard

FirebaseVertexAI/Tests/Unit/Snippets/ChatSnippets.swift

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+// 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 FirebaseCore
+import FirebaseVertexAI
+import XCTest
+
+// These snippet tests are intentionally skipped in CI jobs; see the README file in this directory
+// for instructions on running them manually.
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+final class ChatSnippets: XCTestCase {
+  lazy var model = VertexAI.vertexAI().generativeModel(modelName: "gemini-1.5-flash")
+
+  override func setUpWithError() throws {
+    try FirebaseApp.configureDefaultAppForSnippets()
+  }
+
+  override func tearDown() async throws {
+    await FirebaseApp.deleteDefaultAppForSnippets()
+  }
+
+  func testChatNonStreaming() async throws {
+    // Optionally specify existing chat history
+    let history = [
+      ModelContent(role: "user", parts: "Hello, I have 2 dogs in my house."),
+      ModelContent(role: "model", parts: "Great to meet you. What would you like to know?"),
+    ]
+
+    // Initialize the chat with optional chat history
+    let chat = model.startChat(history: history)
+
+    // To generate text output, call sendMessage and pass in the message
+    let response = try await chat.sendMessage("How many paws are in my house?")
+    print(response.text ?? "No text in response.")
+  }
+
+  func testChatStreaming() async throws {
+    // Optionally specify existing chat history
+    let history = [
+      ModelContent(role: "user", parts: "Hello, I have 2 dogs in my house."),
+      ModelContent(role: "model", parts: "Great to meet you. What would you like to know?"),
+    ]
+
+    // Initialize the chat with optional chat history
+    let chat = model.startChat(history: history)
+
+    // To stream generated text output, call sendMessageStream and pass in the message
+    let contentStream = try chat.sendMessageStream("How many paws are in my house?")
+    for try await chunk in contentStream {
+      if let text = chunk.text {
+        print(text)
+      }
+    }
+  }
+}

FirebaseVertexAI/Tests/Unit/Snippets/TextSnippets.swift

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+// 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 FirebaseCore
+import FirebaseVertexAI
+import XCTest
+
+// These snippet tests are intentionally skipped in CI jobs; see the README file in this directory
+// for instructions on running them manually.
+
+@available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, *)
+final class TextSnippets: XCTestCase {
+  lazy var model = VertexAI.vertexAI().generativeModel(modelName: "gemini-1.5-flash")
+
+  override func setUpWithError() throws {
+    try FirebaseApp.configureDefaultAppForSnippets()
+  }
+
+  override func tearDown() async throws {
+    await FirebaseApp.deleteDefaultAppForSnippets()
+  }
+
+  func testTextOnlyNonStreaming() async throws {
+    // Provide a prompt that contains text
+    let prompt = "Write a story about a magic backpack."
+
+    // To generate text output, call generateContent with the text input
+    let response = try await model.generateContent(prompt)
+    print(response.text ?? "No text in response.")
+  }
+
+  func testTextOnlyStreaming() async throws {
+    // Provide a prompt that contains text
+    let prompt = "Write a story about a magic backpack."
+
+    // To stream generated text output, call generateContentStream with the text input
+    let contentStream = try model.generateContentStream(prompt)
+    for try await chunk in contentStream {
+      if let text = chunk.text {
+        print(text)
+      }
+    }
+  }
+}