### How are you using the lua-language-server? Visual Studio Code Extension (sumneko.lua) ### Which OS are you using? Windows ### What is the issue affecting? Diagnostics/Syntax Checking ### Expected Behaviour Diagnostics nil check does not depend on the field parameter value ```lua ---@class A ---@field b string ---@type A? local a if a.b == "string1" then end -- Need check nil if a.b == "string" then end -- Need check nil ``` ### Actual Behaviour The string value "string" suppresses the triggering of diagnostics, because of type `string` of field **b**.  ### Reproduction steps 1. Copy the sample code 2. Check the diagnostics `a.b == "string"` when **a** should trigger "Need check nil" ### Additional Notes _No response_ ### Log File _No response_