Incorrect understanding of `max_by` return type

[amake]

The following code:

# @return [Integer]
def foo
  [1, 2, 3].max_by(&:abs)
end

Fails to type check with the following error:

% solargraph typecheck --level typed tmp.rb
tmp.rb:2 - Declared return type Integer does not match inferred type Enumerator<Integer, Integer> for #foo
1 problem found.

Looking at the RBS it seems like it does indicate that a single object can be returned:

https://github.com/ruby/rbs/blob/97ed5d9492b9d2050b87dd4b247be4097e970b9d/core/enumerable.rbs#L973-L976

[apiology]

Yeah, I've seen similar with these methods where the return type varies with the arity of arguments / block provided.

This is likely the place to debug: https://github.com/castwide/solargraph/blob/master/lib/solargraph/source/chain/call.rb#L60-L83