According OData V4 spec isof function type parameter should not be enclosed in quotes. However both .NET client lib sends quoted type parameter and service impl requires type to be quoted.

Assemblies affected

OData .Net lib 6.x, 7.x

Reproduce steps

Execute query like
https://services.odata.org/TripPinRESTierService/(S(4dte2qgkqy1lkpudzkpnk4om))/People?$filter=isof(Microsoft.OData.Service.Sample.TrippinInMemory.Models.Employee)

Expected result

Request should return list of Employees like https://services.odata.org/TripPinRESTierService/(S(4dte2qgkqy1lkpudzkpnk4om))/People?$filter=isof('Microsoft.OData.Service.Sample.TrippinInMemory.Models.Employee') request does.

Actual result

Request fails with "Cast or IsOf Function must have a type in its arguments." message.