Lint/AmbiguousBlockAssociation's message is confusing

[eregon]

The message is (for the code using Module.new {}):

Parenthesize the param Module.new {} to make sure that the block
will be associated with the Module.new method call.

But this sounds like spreading fear and doubt when the Ruby parser has no such concepts :)
{} always binds tightly to the call right next to it.
This block {} will never go to using, unless it's rewritten as do ... end.

Expected behavior

A better message, clarifying the true purpose of the cop, which I guess is to differentiate empty Hash literals and blocks.
Maybe

core/module/using_spec.rb:92:9: W: Lint/AmbiguousBlockAssociation: Parenthesize the param
`Module.new {}` to clarify `{}` is a block passed to `Module.new` and not an empty Hash literal.
        using Module.new {}
        ^^^^^^^^^^^^^^^^^^^

However, I find using(Module.new {}) not so beautiful, but that might be subjective.

mod = Module.new
using mod

is likely a better fix.

Actual behavior

core/module/using_spec.rb:92:9: W: Lint/AmbiguousBlockAssociation: Parenthesize the param
Module.new {} to make sure that the block will be associated with the Module.new method call.
        using Module.new {}
        ^^^^^^^^^^^^^^^^^^^

Steps to reproduce the problem

Run RuboCop on a file containing

using Module.new {}

RuboCop version

$ rubocop -V
0.51.0 (using Parser 2.4.0.2, running on ruby 2.4.2 x86_64-linux)

[Drenmi]

Looks like the message was improved once in #4181, but I agree that there's more room for improvement. 🙂

[bbatsov]

I'm closing this ticket due to no recent activity. Feel free to re-open it if you ever come back to it. PRs welcome!