`Class.new(Superclass)` cannot be assigned to a `Superclass`

[vpellan]

When declaring a signature such as:

module Foo
	Bar: StandardError
end

This code will return the error "Cannot assign a value of type ::Class to a constant of type StandardError"

module Foo
	Bar = Class.new(StandardError)
end

This makes sense if we treat Class as any other class, but could it be possible to introduce specific behaviour in this case so that Bar is typed to StandardError, or an anonymous class that inherits from StandardError ?

[Strech]

I think that could be solved with a standard type declaration like this

module Foo
  class Bar < StandardError
  end
end

another way to do it is a module/class alias

module Foo
  class Bar = StandardError
end

[vpellan]

Thanks for your suggestions ! The two suggestions give the same output:

lib/playground/playground.rb:2:2: [error] Cannot assign a value of type `::Class` to a constant of type `singleton(::Foo::Bar)`
│   ::Class <: singleton(::Foo::Bar)
│     ::Module <: singleton(::Foo::Bar)
│       ::Object <: singleton(::Foo::Bar)
│         ::BasicObject <: singleton(::Foo::Bar)
│
│ Diagnostic ID: Ruby::IncompatibleAssignment
│
└   Bar = Class.new(StandardError)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Strech]

I think it works on the current master. Not sure about already released versions