Testing blocks

gistfile1.md

How do you test this?

I want to test that something receives #var from inside the block.

I realize this might be a code smell.

something = Struct.new(:var).new
some_method do
  something.var
end

I want to test that #var was sent to something. In other words, something.should_receive(:var).

It's not clear to me what you're asking--on the surface, it sounds like something.should_receive(:var) would work, but it's clear there's more going on here..

Sorry for not being clear. I want to test that it's happening inside the block.

Sorry for not being clear. I want to test that it's happening inside the block.

Ah, that makes more sense. What is the observable difference in the behavior for something.var to be called in the block vs. outside of it? Is there a way to test that w/o explicitly specifying the relationship between the block and the call to var?

Anyhow, if you still want to test this directly, here's one idea. If there's some observable state change for the duration of the block, then you can pass a block to should_receive to test this. For example, let's use Dir.chdir in place of some_method...then you could test it like so:

it 'does something within another directory' do
  expect(Dir.pwd).not_to eq("other/dir")

  something = Struct.new(:var).new
  something.should_receive(:var) do
    expect(Dir.pwd).to eq("other/dir")
  end

  Dir.chdir("other/dir") do
    something.var
  end

  expect(Dir.pwd).not_to eq("other/dir")
 end