Code Contract gives null warning with ServiceLocator

Question

Using HtmlPage.RegisterScriptableObject("Shell", serviceLocator.GetInstance<Shell>());

gives me a null warning. How can I make this go away?

Answer 1

The warning is that serviceLocator is null?

Without seeing any more of your code (to get an idea of what other contracts might be in play), you could put

Contract.Assume(serviceLocator != null);

on the line above.

Answer 2

Perhaps serviceLocator.GetInstance<Shell>() returns null if an instance is not found.

Try providing an alternative control flow for that situation.

var instance = serviceLocator.GetInstance<Shell>();
if (instance == null)
    throw new InvalidOperationException("Shell instance is missing.");
HtmlPage.RegisterScriptableObject("Shell", instance);