How To Express Change of Associated Data

Testing RSpec
1

Hello–

I’m not sure if I’m pushing too far out of specing a given model, but
here’s what I want to express:

class A < AR::Base
has_many :bs

def okay(segment)
end
end

class B < AR::Base
belongs_to :a
end

it A, “should increase the vote count for a given segment if okayed” do
@a = A.create(stuff)
@a.okay(10) # okay segment 10

here’s where I’m having trouble…

a.bs should have one row, and it should have a segment number of

10 and various other stuff should happen

subsequent @a.okay with different values should transform numbers

in a predictable way. This is handled in

the A model because the transforms occur only in Bs that belong

to a given A.
@a.bs.find_by_segment_number(10).thingie.should be(1) # not too
expressive
@a.okay(9)
@a.bs.find_by_segment_number(9).thingie.should be(1) # still not
too expressive
@a.bs. find_by_segment_number(9).transformed_thingie.should
be(something_else)
end

This kind of spec smells to me, yet I am having trouble figuring out
how to explain, using rspec, exactly what the behavior is to be in a
multi-step sequence.

Anybody have thoughts regarding how this might be done better?

Thanks

2

On Sun, Jul 6, 2008 at 5:43 PM, s.ross [email protected] wrote:

end
various other stuff should happen
end

This kind of spec smells to me, yet I am having trouble figuring out how to
explain, using rspec, exactly what the behavior is to be in a multi-step
sequence.

Anybody have thoughts regarding how this might be done better?

Hi,

You could do

lambda {
@a.okay(9)
}.should change { @a.bs.find_by_segment_number(9) }.
from(nil).to(1)

I do wonder if you might be able to make it a bit more
behavior-oriented, maybe something like

lambda {
@a.okay(9)
}.should change { @a.count_votes_for(9) }.by(1)

I don’t know exactly what you’re trying to get at though, so I can’t
be more specific. At any rate, does using “should change” make it
more readable to you?

Pat

3

On Jul 6, 2008, at 3:00 PM, Pat M. wrote:

def okay(segment)
@a.okay(10) # okay segment 10
@a.bs.find_by_segment_number(10).thingie.should be(1) # not too
explain, using rspec, exactly what the behavior is to be in a multi-
@a.okay(9)
I don’t know exactly what you’re trying to get at though, so I can’t
be more specific. At any rate, does using “should change” make it
more readable to you?

Great suggestion using from and to. I am already using the behavior-
oriented lambda{something_or_other}.should change(B, :count).by(1) for
the straightforward case. The more difficult case is that when that
okay() happens, it may or may not add a row, but it does some
transformations that cause updates to fields in all of the rows
belonging to the A. Sorry I can’t be more specific than A’s and B’s :slight_smile:

And thanks again. Rspec rocks.