https://github.com/github/copilot-sdk/pull/1465

Author: edburns

src/main/java/com/github/copilot/rpc/AgentMode.java

@@ -14,7 +14,7 @@
  * specific mode; defaults to the session's current mode when unset.
  *
  * @see MessageOptions
- * @since 1.1.0
+ * @since 1.0.0
  */
 public enum AgentMode {
 
@@ -67,6 +67,6 @@ public static AgentMode fromValue(String value) {
                 return mode;
             }
         }
-        throw new IllegalArgumentException("Unknown AgentMode: " + value);
+        throw new IllegalArgumentException("Unknown AgentMode value: " + value);
     }
 }

src/test/java/com/github/copilot/AgentModeTest.java

@@ -0,0 +1,70 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *--------------------------------------------------------------------------------------------*/
+
+package com.github.copilot;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.github.copilot.rpc.AgentMode;
+
+/**
+ * Unit tests for {@link AgentMode} serialization, deserialization, and
+ * unknown-value behavior.
+ */
+public class AgentModeTest {
+
+    private final ObjectMapper mapper = new ObjectMapper();
+
+    @ParameterizedTest
+    @EnumSource(AgentMode.class)
+    void jsonRoundTrip_allValues(AgentMode mode) throws Exception {
+        String json = mapper.writeValueAsString(mode);
+        AgentMode deserialized = mapper.readValue(json, AgentMode.class);
+        assertEquals(mode, deserialized);
+    }
+
+    @Test
+    void getValue_returnsExpectedStrings() {
+        assertEquals("interactive", AgentMode.INTERACTIVE.getValue());
+        assertEquals("plan", AgentMode.PLAN.getValue());
+        assertEquals("autopilot", AgentMode.AUTOPILOT.getValue());
+        assertEquals("shell", AgentMode.SHELL.getValue());
+    }
+
+    @Test
+    void fromValue_knownValues_returnsCorrectEnum() {
+        assertEquals(AgentMode.INTERACTIVE, AgentMode.fromValue("interactive"));
+        assertEquals(AgentMode.PLAN, AgentMode.fromValue("plan"));
+        assertEquals(AgentMode.AUTOPILOT, AgentMode.fromValue("autopilot"));
+        assertEquals(AgentMode.SHELL, AgentMode.fromValue("shell"));
+    }
+
+    @Test
+    void fromValue_null_returnsNull() {
+        assertNull(AgentMode.fromValue(null));
+    }
+
+    @Test
+    void fromValue_unknownValue_throwsWithConsistentMessage() {
+        var ex = assertThrows(IllegalArgumentException.class, () -> AgentMode.fromValue("unknown"));
+        assertEquals("Unknown AgentMode value: unknown", ex.getMessage());
+    }
+
+    @Test
+    void jsonDeserialize_unknownValue_throws() {
+        String json = "\"not-a-mode\"";
+        assertThrows(Exception.class, () -> mapper.readValue(json, AgentMode.class));
+    }
+
+    @Test
+    void jsonSerialize_writesStringValue() throws Exception {
+        String json = mapper.writeValueAsString(AgentMode.AUTOPILOT);
+        assertEquals("\"autopilot\"", json);
+    }
+}