From: Pat Maddox <pergesu@...>
Date: 2007-11-15T04:32:25+09:00
Subject: Re: rspec questions: same file? mocks objects as params?

On Nov 14, 2007 11:02 AM, David Weldon <dweldon@gmail.com> wrote:
> I'm just getting started with rspec. Two questions:
>
> 1) Should the rspec be in the same file as the production code? The
> examples on the rspec site seem to indicate they should be in a separate
> file but I wanted to double check.

Specs should be separate.  In a Rails app there's a spec dir that
parallels your app dir.  If you're writing a Ruby app from scratch
then you'll need to create it yourself.  But definitely stick specs in
separate files from production code.


> 2) If I use mocks, am I supposed to pass them as parameters to my
> production code?
>
> If my code looked like:
>
> def read()
>    db = database.instance()
>    db.execute(....)
> end
>
> and I want to do a mock database connection do I have to write the
> production code like:
>
> def read(db=database.instance())
>    db.execute(....)
> end
>
> and then call it with read(my_mock) ?

You can do it that way, or you can stub the call to #instance and have
it return the mock.

Also, without knowing anything about your code :)  I would be more
likely to pass the datastore into the constructor:

class Person
  def initialize(datastore)
    @datastore = datastore
  end

  def read
    conn = @datastore.instance
    conn.execute(...)
  end
end

Then your spec would look something like:

describe Person, " reading a record" do
  before(:each) do
    @mock_connection = mock("db connection")
    @mock_pool = stub("connection pool", :instance => @mock_connection)

    @person = Person.new @mock_pool
  end

  it "should get a connection" do
    @mock_pool.should_receive(:instance).and_return @mock_connection
    @person.read
  end

  it "should select data from the database" do
    @mock_connection.should_receive(:execute).with(...)
    @person.read
  end
end

Which is sort of ugly because you have a mock returning a mock, but
such is life with a singleton :)

Pat