Rails 7.1 breaks receive().with

[palkan]

Your environment

• Ruby version: 3.2
• rspec-mocks version: 3.12.2
• Rails version: main.

Steps to reproduce

In a Rails application (i.e., with Rails loaded), define a method expectation:

mock = instance_double("Hash")
allow(mock).to receive(:key?).with(:x) { 1 }

expect(mock.key?(:x)).to eq 1

Expected behavior

Pass.

Actual behavior

ArgumentError:
       wrong number of arguments (given 1, expected 0)
     # ../rails/activesupport/lib/active_support/core_ext/object/with.rb:24:in `with'

What happened?

Rails monkey-patched Object#with rails/rails#46681 /cc @byroot

RSpec receive matcher defines chain methods only for undefined methods:

rspec-mocks/lib/rspec/mocks/matchers/receive.rb

Lines 58 to 59 in 4a1032b

	MessageExpectation.public_instance_methods(false).each do |method|
	next if method_defined?(method)

Since #with is defined on Object, the with modifier is no longer available.

[nobu]

Why does MessageExpectation need to b e a subclass of Object, not BasicObject?

[byroot]

Even then, why would it not redefine existing methods? I'll git blame to see if I can find the reason for this.

[byroot]

Ah, I think the intent is to not redefine methods directly defined in Receive, since we're copying all the matchers. method_defined?(name, false) would fix it I think.

[byroot]

I think I have a fix for it, but GitHub seems to be having issues, I get an error message when trying to create the PR....

Pull request creation failed. Validation failed: You can't perform that action at this time.

https:/rspec/rspec-mocks/compare/rspec:main...casperisfine:receiver-with?expand=1

[pirj]

@byroot I’ve opened one, does it work for you?

[byroot]

Sure, thank you.