RSpec how to stub open?

I've been trying to stub open, the open-uri version, and I'm not succeeding.

I've tried doing the following but the request keeps going through:

Kernel.should_receive(:open).and_return("Whatever for now")

I've also tried to do

OpenURI::OpenRead.should_receive(:open).and_return("Whatever for now")

Since I 开发者_开发百科tracked down that was where HTTP requests were made in OpenURI.

Thanks in advance for any suggestions!

Here is what I do

class Gateway

  def do_something
    open('http://example.com').read
  end

end

In my spec i do the following:

describe 'communication' do

  it 'should receive valid response from example.com' do
    gateway = Gateway.new
    gateway.stub_chain(:open, :read).and_return('Remote server response')

    gateway.do_something.should == "Remote server response"
  end 

end

I found a solution here on Stack Overflow after some more time on Google (I can't believe I didn't find this before).

Explanation taken from here and written by Tony Pitluga (not linkable).

If you are calling sleep within the context of an object, you should stub it on the object[...]
The key is, to stub sleep on whatever "self" is in the context where sleep is called.

So I did this and it all worked out:

let(:read) { mock('open') }

it "should return the new log-level when the log level was set successfully" do
    read.stub(:read).and_return('log-level set to 1')
    kannel.should_receive(:open).and_return(read)

    kannel.set_log_level(1).should == 1
  end

I'd recommend using something to stub the network instead. I believe the current favorite for doing so is FakeWeb [docs]. You may also be interested in fakeweb-matcher for rspec.

Alas, I think FakeWeb might not work with open(), actually, it stubs Net::HTTP, so I'm not sure if that will work. Any chance of not using open()? :)