The variable type rule has an issue when the variable type is a non-null type.

[michaelstaib]

Describe the bug
The variable type rule has an issue when the variable type is a non-null type.

To Reproduce
The following query is rejected by the server:

query f($x: Episode!){
  hero(episode:$x)
  {
    name
  }
}

with the following error:

{
  "errors": [
    {
      "VariableName": "x",
      "Message": "The variable value is not of the correct type."
    }
  ]
}

The hero signature looks like the following hero(episode: Episode!): Character.

Expected behavior
The query should have not been rejected.

[michaelstaib]

private void CheckForInvalidValueType(in Variable variable)
        {
            if (!variable.Type.IsInstanceOfType(variable.Value))
            {
                throw new QueryException(new VariableError(
                    "The variable value is not of the correct type.",
                    variable.Name));
            }
        }

[michaelstaib]

The bug is caused by our temporary workaround to fix a serialization issue with enums. So, now we have to put a good solution in place and not another workaround.

[michaelstaib]

This issue is related to #219 and #218

[michaelstaib]

This issue is fixed with PR #274