Add java snippets to compilation tests

ai-logic/firebase-ai/src/testUtil/java/com/google/firebase/ai/JavaCompileTests.java

@@ -161,19 +161,26 @@ private GenerationConfig getGenerationConfig() {
   private Schema getSchema() {
     return Schema.obj(
         Map.of(
-            "foo", Schema.numInt(),
-            "bar", Schema.numInt("Some integer"),
-            "baz", Schema.numInt("Some integer", false),
-            "qux", Schema.numDouble(),
-            "quux", Schema.numFloat("Some floating point number"),
-            "xyzzy", Schema.array(Schema.numInt(), "A list of integers"),
-            "fee", Schema.numLong(),
+            "foo",
+            Schema.numInt(),
+            "bar",
+            Schema.numInt("Some integer"),
+            "baz",
+            Schema.numInt("Some integer", false),
+            "qux",
+            Schema.numDouble(),
+            "quux",
+            Schema.numFloat("Some floating point number"),
+            "xyzzy",
+            Schema.array(Schema.numInt(), "A list of integers"),
+            "fee",
+            Schema.numLong(),
             "ber",
-                Schema.obj(
-                    Map.of(
-                        "bez", Schema.array(Schema.numDouble("Nullable double", true)),
-                        "qez", Schema.enumeration(List.of("A", "B", "C"), "One of 3 letters"),
-                        "qeez", Schema.str("A funny string")))));
+            Schema.obj(
+                Map.of(
+                    "bez", Schema.array(Schema.numDouble("Nullable double", true)),
+                    "qez", Schema.enumeration(List.of("A", "B", "C"), "One of 3 letters"),
+                    "qeez", Schema.str("A funny string")))));
   }
 
   private LiveGenerationConfig getLiveConfig() {

ai-logic/firebase-ai/src/testUtil/java/com/google/firebase/ai/JavaSnippetCompileTests.java

@@ -0,0 +1,185 @@
+/*
+ * Copyright 2026 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.
+ */
+
+package java.com.google.firebase.ai;
+
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.firebase.ai.FirebaseAI;
+import com.google.firebase.ai.TemplateChat;
+import com.google.firebase.ai.TemplateGenerativeModel;
+import com.google.firebase.ai.java.TemplateChatFutures;
+import com.google.firebase.ai.type.Content;
+import com.google.firebase.ai.type.FunctionCallPart;
+import com.google.firebase.ai.type.GenerateContentResponse;
+import com.google.firebase.ai.type.GenerativeBackend;
+import com.google.firebase.ai.type.JsonSchema;
+import com.google.firebase.ai.type.RequestOptions;
+import com.google.firebase.ai.type.TemplateFunctionDeclaration;
+import com.google.firebase.ai.type.TemplateTool;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import kotlinx.serialization.json.JsonObject;
+import kotlinx.serialization.json.JsonPrimitive;
+
+/**
+ * Contains various Java snippets used in documentation for Gemini/Vertex AI.
+ * Compilation is a good litmus test that the snippets are sane.
+ */
+public class JavaSnippetCompileTests {
+  // Various stubs for compilation
+  private final Executor executor = Executors.newSingleThreadExecutor();
+
+  private Object fetchWeather(String city, String state, String date) {
+    return null; // Stub
+  }
+
+  // Snippets
+
+  // https://firebase.google.com/docs/ai-logic/server-prompt-templates/multi-turn-interactions?api=dev#chat-use-template-in-code
+  public void template_chat() {
+    // ...
+
+    // Initialize the Vertex AI Gemini API backend service.
+    TemplateGenerativeModel templateModel =
+        FirebaseAI.getInstance(GenerativeBackend.vertexAI("global")).templateGenerativeModel();
+    // Initialize TemplateChat with history and inputs
+    TemplateChat templateChat =
+        templateModel.startChat("my-chat-template-v1-0-0", Map.of(), Collections.emptyList());
+    TemplateChatFutures chatFutures = TemplateChatFutures.from(templateChat);
+
+    // Send a message asynchronously
+    Content prompt = new Content.Builder().addText("I need a copy of my invoice.").build();
+    ListenableFuture<GenerateContentResponse> responseFuture = chatFutures.sendMessage(prompt);
+
+    Futures.addCallback(
+        responseFuture,
+        new FutureCallback<GenerateContentResponse>() {
+          @Override
+          public void onSuccess(GenerateContentResponse result) {
+            System.out.println("Response: " + result.getText());
+          }
+
+          @Override
+          public void onFailure(Throwable t) {
+            t.printStackTrace();
+          }
+        },
+        executor);
+  }
+
+  // https://firebase.google.com/docs/ai-logic/server-prompt-templates/multi-turn-interactions?api=dev#function-calling-use-template-in-code
+  public void template_functionCallingSchemaInTemplate(String userMessage) {
+    // ...
+
+    // Initialize the Vertex AI Gemini API backend service.
+    // Create a `TemplateGenerativeModel` instance.
+    TemplateGenerativeModel model =
+        FirebaseAI.getInstance(GenerativeBackend.vertexAI("global")).templateGenerativeModel();
+
+    // Start a chat session with a template that has functions listed as tools.
+    TemplateChat chatSession =
+        model.startChat(
+            "my-function-calling-template-v1-0-0", // Template ID
+            Map.of(), // Inputs
+            List.of() // History
+            );
+    TemplateChatFutures chatFutures = TemplateChatFutures.from(chatSession);
+
+    // Send a message that might trigger a function call.
+    Content prompt = new Content.Builder().addText(userMessage).build();
+    ListenableFuture<GenerateContentResponse> responseFuture = chatFutures.sendMessage(prompt);
+
+    Futures.addCallback(
+        responseFuture,
+        new FutureCallback<GenerateContentResponse>() {
+          @Override
+          public void onSuccess(GenerateContentResponse result) {
+            // When the model responds with one or more function calls, invoke the function(s).
+            // Note that this is the same as when *not* using server prompt templates.
+            for (FunctionCallPart callPart : result.getFunctionCalls()) {
+              if ("fetchWeather".equals(callPart.getName())) {
+                // Forward the structured input data from the model to the hypothetical external
+                // API.
+                JsonObject location = (JsonObject) callPart.getArgs().get("location");
+                String city = ((JsonPrimitive) location.get("city")).getContent();
+                String state = ((JsonPrimitive) location.get("state")).getContent();
+                String date = ((JsonPrimitive) callPart.getArgs().get("date")).getContent();
+                Object response = fetchWeather(city, state, date);
+              }
+            }
+          }
+
+          @Override
+          public void onFailure(Throwable t) {
+            t.printStackTrace();
+          }
+        },
+        executor);
+  }
+
+  // https://firebase.google.com/docs/ai-logic/server-prompt-templates/multi-turn-interactions?api=dev#function-calling-schema-defined-in-code
+  public void template_functionCallingSchemaInCode() {
+    TemplateFunctionDeclaration tool =
+        new TemplateFunctionDeclaration(
+            "fetchWeather", // Name
+            JsonSchema.obj( // Parameters
+                Map.of(
+                    "location",
+                        JsonSchema.obj(
+                            Map.of(
+                                "city", JsonSchema.string("The city of the location."),
+                                "state", JsonSchema.string("The state of the location."),
+                                "zipCode",
+                                    JsonSchema.string(
+                                        "Optional zip code of the location", true // Nullable
+                                        )),
+                            List.of("zipCode"),
+                            ""),
+                    "date",
+                        JsonSchema.string(
+                            "The date for which to get the weather. Date must be in the format: YY-MM-DD."),
+                    "unit",
+                        JsonSchema.enumeration(
+                            List.of("CELSIUS", "FAHRENHEIT"),
+                            "The temperature unit.",
+                            true // Nullable
+                            ))),
+            JsonSchema.string("A description of the current weather."));
+    TemplateGenerativeModel templateModel =
+        FirebaseAI.getInstance(GenerativeBackend.vertexAI("global"))
+            .templateGenerativeModel(
+                new RequestOptions(),
+                List.of(TemplateTool.functionDeclarations(List.of(tool), List.of())));
+    TemplateChat chat =
+        templateModel.startChat(
+            "my-function-calling-template-with-no-function-schema-v1-0-0", Map.of(), List.of());
+    TemplateChatFutures futures = TemplateChatFutures.from(chat);
+
+    // Send a message that might trigger a function call.
+    // ...
+
+    // When the model responds with one or more function calls, invoke the function(s).
+    // Note that this is the same as when *not* using server prompt templates.
+    // ...
+
+    // Forward the structured input data from the model to the hypothetical external API.
+  }
+}