Related test case: Base Information / Base Info Type System / ObjectTypesValidation.js

In case of an Input- or OutputArguments property with no value the server might either respond with a NULL/empty value or exclude the value at by clearing the Value bit in the EncodingMask. In the latter case the following validation in infoFactory.js:1532/1587 will fail:

// Argument is an extensionObject; and Arguments is an array!
if (!Assert.Equal(VariantArrayType.Array, xReadHelper.Response.Results[0].Value.ArrayType, ....

FWIW, the assertion for the OutputArguments validation does not print the concerned NodeId like it is done for the InputArguments assertion. It might be considered to add the NodeId to the according OutputArguments assertion call.