In the documentation page for ReflectionService, the code section that shows the declaration for the ReflectedProperty global type has a typo in it:
The underlined part should be written as “DeprecationMessage”, without the additional “i”.
This must be a typo because in another global type of ReflectionService, the ReflectedClass one, the key appears with the correct “DeprecationMessage” name:
The typo is available in both the documentation page and over at Roblox Studio when scripting with the global type. A good thing is that ReflectionService:GetPropertiesOfClass() returns an array of the correct ReflectedProperty global type, without the typo! It’s just the fact that there is this typo that must be fixed.
Link: ReflectionService:GetPropertiesOfClass(), then scroll down a bit until you will see the declaration for the ReflectedProperty global type.
Also, I’m so sorry if this isn’t the right place to report this typo and that I should’ve reported it in this thread, but after looking at what should be reported and what shouldn’t be reported in that thread I’ve understood that for this type of typo I must create a new bug report.
Page URL: https://create.roblox.com/docs/reference/engine/classes/ReflectionService#GetPropertiesOfClass

