Rspec-rails: Proposal of new matcher

[taish]

I want matcher like in? method of acctive support
https://github.com/rails/rails/blob/master/activesupport/lib/active_support/core_ext/object/inclusion.rb#L10

I think it's useful if there is this
what do you think?

or similar function is already implemented?

[myronmarston]

We support all predicates via method_missing. in? can be triggered via be_in:

expect(3).to be_in([1, 2, 3])