Throw more informative exception on invalid new session response in .NET

SeleniumHQ · Sep 6, 2019 · 5caa106 · 5caa106
1 parent 87384d1
commit 5caa106
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/dotnet/src/webdriver/Remote/RemoteWebDriver.cs b/dotnet/src/webdriver/Remote/RemoteWebDriver.cs
@@ -986,7 +986,13 @@ protected void StartSession(ICapabilities desiredCapabilities)
 
             Response response = this.Execute(DriverCommand.NewSession, parameters);
 
-            Dictionary<string, object> rawCapabilities = (Dictionary<string, object>)response.Value;
+            Dictionary<string, object> rawCapabilities = response.Value as Dictionary<string, object>;
+            if (rawCapabilities == null)
+            {
+                string errorMessage = string.Format(CultureInfo.InvariantCulture, "The new session command returned a value ('{0}') that is not a valid JSON object.", response.Value);
+                throw new WebDriverException(errorMessage);
+            }
+
             ReturnedCapabilities returnedCapabilities = new ReturnedCapabilities(rawCapabilities);
             this.capabilities = returnedCapabilities;
             this.sessionId = new SessionId(response.SessionId);