Refactoring in Crystal

rename.cr

class Foo
  def foo(x)
    # Rename this call from "bar" to "baz":
    # What other things change in this file?
    #
    # According to what's called, Bar#bar needs
    # to change. But what about Baz#bar? I can
    # also pass Baz.new to Foo.new.foo. There's
    # no way to tell if that should be renamed too.
    #
    # Renaming based on usage isn't correct. The
    # only solution to this is to make all methods
    # have mandatory argument types, and return
    # types. Then you'll know for sure what needs
    # to be renamed.
    x.bar(1)
  end
end

class Bar
  def bar(x)
  end
end

class Baz
  def bar(x)
  end
end

Foo.new.foo(Bar.new)

Also, expanding on @faustinoaq's comment on C++ refactoring tools, clang-rename is an attempt at doing this sort of thing, though it has plenty of restrictions on what it is really capable of.

Personally, local variable renaming, and small refactors such as "extract this subexpression to a variable" would be my 99% usecase for a refactoring tool. Renaming methods at the callsite seems complex, simply look up definitions and rename at the method definition site. For renaming at method definition, first type the whole program, rename all the places where we call the method on the non-union type, then give me a list of places where the method is called on a union which includes the type, and let me decide what to do on a case-by-case basis.

Well, I guess I can add at least basic rename support 👍 , see: crystal-lang-tools/scry#101 (comment)