test:Add unit tests

core/src/main/java/com/google/adk/flows/llmflows/Identity.java

@@ -35,12 +35,10 @@ public Single<RequestProcessor.RequestProcessingResult> processRequest(
     StringBuilder builder =
         new StringBuilder()
             .append("You are an agent. Your internal name is ")
-            .append("\"")
             .append(agent.name())
-            .append("\"")
             .append(".");
     if (!Strings.isNullOrEmpty(agent.description())) {
-      builder.append(" The description about you is \"").append(agent.description()).append("\".");
+      builder.append(" The description about you is ").append(agent.description());
     }
     return Single.just(
         RequestProcessor.RequestProcessingResult.create(

core/src/main/java/com/google/adk/models/LlmRequest.java

@@ -16,8 +16,6 @@
 
 package com.google.adk.models;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkState;
 import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.common.collect.ImmutableMap.toImmutableMap;
 
@@ -172,29 +170,14 @@ public final Builder appendInstructions(List<String> instructions) {
       return liveConnectConfig(liveCfg.toBuilder().systemInstruction(newLiveSi).build());
     }
 
-    private Content addInstructions(
-        Optional<Content> currentSystemInstruction, List<String> additionalInstructions) {
-      checkArgument(
-          currentSystemInstruction.isEmpty()
-              || currentSystemInstruction.get().parts().map(parts -> parts.size()).orElse(0) <= 1,
-          "At most one instruction is supported.");
-
-      // Either append to the existing instruction, or create a new one.
-      String instructions = String.join("\n\n", additionalInstructions);
-
-      Optional<Part> part =
-          currentSystemInstruction
-              .flatMap(Content::parts)
-              .flatMap(parts -> parts.stream().findFirst());
-      if (part.isEmpty() || part.get().text().isEmpty()) {
-        part = Optional.of(Part.fromText(instructions));
-      } else {
-        part = Optional.of(Part.fromText(part.get().text().get() + "\n\n" + instructions));
-      }
-      checkState(part.isPresent(), "Failed to create instruction.");
+    private Content addInstructions(Optional<Content> currentSi, List<String> newInst) {
+      ImmutableList.Builder<Part> parts = ImmutableList.builder();
+      currentSi.flatMap(Content::parts).ifPresent(parts::addAll);
+
+      newInst.stream().map(Part::fromText).forEach(parts::add);
 
-      String role = currentSystemInstruction.flatMap(Content::role).orElse("user");
-      return Content.builder().parts(part.get()).role(role).build();
+      String role = currentSi.flatMap(Content::role).orElse("user");
+      return Content.builder().parts(parts.build()).role(role).build();
     }
 
     @CanIgnoreReturnValue

core/src/test/java/com/google/adk/agents/CallbacksTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.agents;
 
 import static com.google.adk.testing.TestUtils.createEvent;

core/src/test/java/com/google/adk/agents/InstructionTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.agents;
 
 import static com.google.adk.testing.TestUtils.createInvocationContext;

core/src/test/java/com/google/adk/agents/ParallelAgentTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.agents;
 
 import static com.google.adk.testing.TestUtils.createInvocationContext;

core/src/test/java/com/google/adk/agents/RunConfigTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.agents;
 
 import static com.google.common.truth.Truth.assertThat;

core/src/test/java/com/google/adk/events/EventActionsTest.java

@@ -0,0 +1,90 @@
+/*
+ * 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.
+ */
+
+package com.google.adk.events;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.adk.tools.ToolConfirmation;
+import com.google.common.collect.ImmutableMap;
+import com.google.genai.types.Part;
+import java.util.concurrent.ConcurrentHashMap;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public final class EventActionsTest {
+
+  private static final Part PART = Part.builder().text("text").build();
+  private static final ToolConfirmation TOOL_CONFIRMATION =
+      ToolConfirmation.builder().hint("hint").confirmed(true).build();
+
+  @Test
+  public void toBuilder_createsBuilderWithSameValues() {
+    EventActions eventActionsWithSkipSummarization =
+        EventActions.builder().skipSummarization(true).build();
+
+    EventActions eventActionsAfterRebuild = eventActionsWithSkipSummarization.toBuilder().build();
+
+    assertThat(eventActionsAfterRebuild).isEqualTo(eventActionsWithSkipSummarization);
+  }
+
+  @Test
+  public void merge_mergesAllFields() {
+    EventActions eventActions1 =
+        EventActions.builder()
+            .skipSummarization(true)
+            .stateDelta(new ConcurrentHashMap<>(ImmutableMap.of("key1", "value1")))
+            .artifactDelta(new ConcurrentHashMap<>(ImmutableMap.of("artifact1", PART)))
+            .requestedAuthConfigs(
+                new ConcurrentHashMap<>(
+                    ImmutableMap.of("config1", new ConcurrentHashMap<>(ImmutableMap.of("k", "v")))))
+            .requestedToolConfirmations(
+                new ConcurrentHashMap<>(ImmutableMap.of("tool1", TOOL_CONFIRMATION)))
+            .build();
+    EventActions eventActions2 =
+        EventActions.builder()
+            .stateDelta(new ConcurrentHashMap<>(ImmutableMap.of("key2", "value2")))
+            .artifactDelta(new ConcurrentHashMap<>(ImmutableMap.of("artifact2", PART)))
+            .transferToAgent("agentId")
+            .escalate(true)
+            .requestedAuthConfigs(
+                new ConcurrentHashMap<>(
+                    ImmutableMap.of("config2", new ConcurrentHashMap<>(ImmutableMap.of("k", "v")))))
+            .requestedToolConfirmations(
+                new ConcurrentHashMap<>(ImmutableMap.of("tool2", TOOL_CONFIRMATION)))
+            .endInvocation(true)
+            .build();
+
+    EventActions merged = eventActions1.toBuilder().merge(eventActions2).build();
+
+    assertThat(merged.skipSummarization()).hasValue(true);
+    assertThat(merged.stateDelta()).containsExactly("key1", "value1", "key2", "value2");
+    assertThat(merged.artifactDelta()).containsExactly("artifact1", PART, "artifact2", PART);
+    assertThat(merged.transferToAgent()).hasValue("agentId");
+    assertThat(merged.escalate()).hasValue(true);
+    assertThat(merged.requestedAuthConfigs())
+        .containsExactly(
+            "config1",
+            new ConcurrentHashMap<>(ImmutableMap.of("k", "v")),
+            "config2",
+            new ConcurrentHashMap<>(ImmutableMap.of("k", "v")));
+    assertThat(merged.requestedToolConfirmations())
+        .containsExactly("tool1", TOOL_CONFIRMATION, "tool2", TOOL_CONFIRMATION);
+    assertThat(merged.endInvocation()).hasValue(true);
+  }
+}

core/src/test/java/com/google/adk/events/EventTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.events;
 
 import static com.google.common.truth.Truth.assertThat;

core/src/test/java/com/google/adk/flows/llmflows/InstructionsTest.java

@@ -257,6 +257,7 @@ public void processRequest_agentInstructionAndGlobalInstruction_bothAreAppendedT
         instructionsProcessor.processRequest(context, initialRequest).blockingGet();
 
     assertThat(result.updatedRequest().getSystemInstructions())
-        .containsExactly("Global instruction.\n\nAgent instruction.");
+        .containsExactly("Global instruction.", "Agent instruction.")
+        .inOrder();
   }
 }

core/src/test/java/com/google/adk/models/LlmRequestTest.java

@@ -120,9 +120,9 @@ public void appendInstructions_existingInstruction_appendsNewInstructionCorrectl
     assertThat(request.config()).isPresent();
     Content systemInstruction = request.config().get().systemInstruction().get();
     assertThat(systemInstruction.role()).hasValue("system");
-    assertThat(systemInstruction.parts().get()).hasSize(1);
-    assertThat(systemInstruction.parts().get().get(0).text())
-        .hasValue(initialInstructionText + "\n\n" + newInstructionText);
+    assertThat(systemInstruction.parts().get()).hasSize(2);
+    assertThat(systemInstruction.parts().get().get(0).text()).hasValue(initialInstructionText);
+    assertThat(systemInstruction.parts().get().get(1).text()).hasValue(newInstructionText);
 
     assertThat(request.liveConnectConfig().systemInstruction()).isPresent();
     Content liveSystemInstruction = request.liveConnectConfig().systemInstruction().get();
@@ -154,9 +154,10 @@ public void appendInstructions_existingInstruction_appendsNewInstructionCorrectl
     assertThat(request.liveConnectConfig().systemInstruction()).isPresent();
     Content liveSystemInstruction = request.liveConnectConfig().systemInstruction().get();
     assertThat(liveSystemInstruction.role()).hasValue("system"); // Role preserved
-    assertThat(liveSystemInstruction.parts().get()).hasSize(1);
+    assertThat(liveSystemInstruction.parts().get()).hasSize(2);
     assertThat(liveSystemInstruction.parts().get().get(0).text())
-        .hasValue(initialLiveInstructionText + "\n\n" + newInstructionText);
+        .hasValue(initialLiveInstructionText);
+    assertThat(liveSystemInstruction.parts().get().get(1).text()).hasValue(newInstructionText);
 
     // Assertions for main config (should get the new instruction with default role)
     assertThat(request.config()).isPresent();
@@ -195,16 +196,16 @@ public void appendInstructions_multipleInstructions_appendsAllInOrder() {
 
     assertThat(request.config()).isPresent();
     Content systemInstruction = request.config().get().systemInstruction().get();
-    assertThat(systemInstruction.parts().get()).hasSize(1);
-    assertThat(systemInstruction.parts().get().get(0).text())
-        .hasValue(instruction1 + "\n\n" + instruction2);
+    assertThat(systemInstruction.parts().get()).hasSize(2);
+    assertThat(systemInstruction.parts().get().get(0).text()).hasValue(instruction1);
+    assertThat(systemInstruction.parts().get().get(1).text()).hasValue(instruction2);
 
     assertThat(request.liveConnectConfig().systemInstruction()).isPresent();
     Content liveSystemInstruction = request.liveConnectConfig().systemInstruction().get();
     assertThat(liveSystemInstruction.role()).hasValue("user");
-    assertThat(liveSystemInstruction.parts().get()).hasSize(1);
-    assertThat(liveSystemInstruction.parts().get().get(0).text())
-        .hasValue(instruction1 + "\n\n" + instruction2);
+    assertThat(liveSystemInstruction.parts().get()).hasSize(2);
+    assertThat(liveSystemInstruction.parts().get().get(0).text()).hasValue(instruction1);
+    assertThat(liveSystemInstruction.parts().get().get(1).text()).hasValue(instruction2);
   }
 
   @Test
@@ -305,7 +306,7 @@ public void getSystemInstructions_whenPresent_returnsList() {
             .appendInstructions(ImmutableList.of(instruction1, instruction2))
             .build();
     assertThat(request.getSystemInstructions())
-        .containsExactly(instruction1 + "\n\n" + instruction2)
+        .containsExactly(instruction1, instruction2)
         .inOrder();
   }
 }

core/src/test/java/com/google/adk/plugins/BasePluginTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.plugins;
 
 import com.google.adk.agents.CallbackContext;

core/src/test/java/com/google/adk/plugins/LoggingPluginTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.plugins;
 
 import static org.mockito.Mockito.when;

core/src/test/java/com/google/adk/plugins/PluginManagerTest.java

@@ -1,3 +1,19 @@
+/*
+ * 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.
+ */
+
 package com.google.adk.plugins;
 
 import static com.google.common.truth.Truth.assertThat;