RSpec any_instance deprecation: how to fix it?

Question

In my Rails project I'm using rspec-mocks using any_instance but I want to avoid this deprecation message:

Using any_instance from rspec-mocks' old :should syntax without explicitly enabling the syntax is deprecated. Use the new :expect syntax or explicitly enable :should instead.

Here is my specs:

describe (".create") do   it 'should return error when...' do     User.any_instance.stub(:save).and_return(false)     post :create, user: {name: "foo", surname: "bar"}, format: :json     expect(response.status).to eq(422)   end end 

Here is my controller:

def create     @user = User.create(user_params)     if @user.save       render json: @user, status: :created, location: @user     else       render json: @user.errors, status: :unprocessable_entity     end end 

I'd like to use the new :expect syntax but I can't find how to use it properly.

I'm using RSpec 3.0.2.

Answer 1

Use allow_any_instance_of:

describe (".create") do   it 'returns error when...' do     allow_any_instance_of(User).to receive(:save).and_return(false)     post :create, user: {name: "foo", surname: "bar"}, format: :json     expect(response.status).to eq(422)   end end 

Answer 2

I am able to reproduce it :

In my test.rb file :-

#!/usr/bin/env ruby  class Foo   def baz     11   end end 

In my test_spec.rb file

require_relative "../test.rb"  describe Foo do   it "invokes #baz" do     Foo.any_instance.stub(:baz).and_return(20)     expect(subject.baz).to eq(20)   end end 

Now If I run it :-

arup@linux-wzza:~/Ruby> rspec .  Deprecation Warnings:  Using `any_instance` from rspec-mocks' old `:should` syntax without explicitly enabling the syntax is deprecated. Use the new `:expect` syntax or explicitly enable `:should` instead. Called from /home/arup/Ruby/spec/test_spec.rb:4:in `block (2 levels) in <top (required)>'. 

Now, I found the changelog

allow(Klass.any_instance) and expect(Klass.any_instance) now print a warning. This is usually a mistake, and users usually want allow_any_instance_of or expect_any_instance_of instead. (Sam Phippen)

I change test_spec.rb as below :

require_relative "../test.rb"  describe Foo do   it "invokes #baz" do     expect_any_instance_of(Foo).to receive(:baz).and_return(20)     expect(subject.baz).to eq(20)   end end 

and it works perfectly :-

arup@linux-wzza:~/Ruby> rspec .  Finished in 0.01652 seconds (files took 0.74285 seconds to load) 1 example, 0 failures arup@linux-wzza:~/Ruby>