Fix ESLint error, update .NET test to verify model_change event, add skipped Go test

Co-authored-by: SteveSandersonMS <1101362+SteveSandersonMS@users.noreply.github.com>

Author: Copilot

dotnet/test/SessionTests.cs

@@ -447,12 +447,13 @@ public async Task Should_Set_Model_On_Existing_Session()
     {
         var session = await CreateSessionAsync();
 
-        // SetModel should not throw
+        // Subscribe for the model change event before calling SetModelAsync
+        var modelChangedTask = TestHelper.GetNextEventOfTypeAsync<SessionModelChangeEvent>(session);
+
         await session.SetModelAsync("gpt-4.1");
 
-        // Session should still be usable after model change
-        await session.SendAsync(new MessageOptions { Prompt = "What is 1+1?" });
-        var assistantMessage = await TestHelper.GetFinalAssistantMessageAsync(session);
-        Assert.NotNull(assistantMessage);
+        // Verify a model_change event was emitted with the new model
+        var modelChanged = await modelChangedTask;
+        Assert.Equal("gpt-4.1", modelChanged.Data.NewModel);
     }
 }

go/internal/e2e/rpc_test.go

@@ -189,6 +189,23 @@ func TestSessionRpc(t *testing.T) {
 		}
 	})
 
+	// session.model.switchTo is defined in schema but not yet implemented in CLI
+	t.Run("should call session.SetModel", func(t *testing.T) {
+		t.Skip("session.model.switchTo not yet implemented in CLI")
+
+		session, err := client.CreateSession(t.Context(), &copilot.SessionConfig{
+			OnPermissionRequest: copilot.PermissionHandler.ApproveAll,
+			Model:               "claude-sonnet-4.5",
+		})
+		if err != nil {
+			t.Fatalf("Failed to create session: %v", err)
+		}
+
+		if err := session.SetModel(t.Context(), "gpt-4.1"); err != nil {
+			t.Fatalf("SetModel returned error: %v", err)
+		}
+	})
+
 	t.Run("should get and set session mode", func(t *testing.T) {
 		session, err := client.CreateSession(t.Context(), &copilot.SessionConfig{OnPermissionRequest: copilot.PermissionHandler.ApproveAll})
 		if err != nil {

nodejs/test/client.test.ts

@@ -89,7 +89,7 @@ describe("CopilotClient", () => {
 
         // Mock sendRequest to capture the call without hitting the runtime
         const spy = vi.spyOn((client as any).connection!, "sendRequest")
-            .mockImplementation(async (method: string, params: any) => {
+            .mockImplementation(async (method: string, _params: any) => {
                 if (method === "session.model.switchTo") return {};
                 // Fall through for other methods (shouldn't be called)
                 throw new Error(`Unexpected method: ${method}`);