Check for existence of mark in extension

[dipanshubhanot]

I want to make sure that a particular mark extension(A) excludes another mark(B). However, there is a runtime UnknownMarkError if mark B is not added to the editor and mark A excludes mark B.

Is there a way for mark A to check if mark B exists to avoid this runtime error?

[philippkuehn]

Unfortunately not. This is a limitation of ProseMirror.