How to implement testing?

Rails
1

Hi people,

i’m wondering what’s the best way to test your rails application.
Should you constantly write tests while your writing your application
code? (method -> test method -> method -> etc.) Or should you focus on
building your application and than building the tests?

Thanks for your advice.

2

Hi Petar,

A good advise is to use small steps. Create a test, then write (as a
rule of thumb) max. 10 lines of code, or a small function. Repeat until
you are done :wink:

IsBOF

3

Hi Petar,

If you can start mastering the concepts of Test Driven Development, you
would be doing yourself a huge favor. This is what I do:

  1. Create a scaffold_resource for the functionality and model I want to
    build (I am really into RESTful development these days)
  2. Write an integration test that contains its own Domain Specific
    Language (or DSL) so I can write my test cases in english. I basically
    write out a user story of what I want this part of the app to do. I’ll
    put an example after this list.
  3. Run my integration test and watch it fail in a blaze of glory.
  4. Write the code for my migration and model to provide the model-based
    functionality needed for the integration test.
  5. Run the unit tests built by the scaffold, then work the code in the
    model until the unit tests pass.
  6. Write the controller code required to make my integration tests
    pass. I usually do these one at a time (my integration tests have a
    number of small scenarios to test in them). Some of the tests will
    usually pass with the stuff the scaffold generates. That is considered
    a bonus! I work the rest one at a time, running the test in between
    each iteration, until everything works.

Now if your integration test is a good representation of the user story
for that functionality, when you get to this point, your code should be
fairly complete. All you should have to do is get your views in order
and you’re golden.

Here is an example integration test that I have used:

class ForumTest < ActionController::IntegrationTest
fixtures :forums, :forum_posts, :users

def test_forum
quentin = enter_site(:quentin)
quentin.views_forum_page
forum = quentin.selects_forum
quentin.views_posts forum
quentin.tries_to_post forum
quentin.logs_in(“quentin”, “test”, forum)
q_post = quentin.posts_to_forum forum

aaron = enter_site(:aaron)
aaron.logs_in("aaron", "test")
posts = aaron.searches_forums
a_post = aaron.selects_post_from_results q_post
a_reply = aaron.replies_to_post(forum, a_post)

quentin.views_posts forum
reply = quentin.notes_new_reply q_post

quentin.is_reply_aarons_post?(reply, a_reply)

end

private

module ForumTestDSL
include ERB::Util

attr_writer :name

def views_forum_page
  ...
end

def selects_forum
  ...
end

def views_posts(forum)
 ...
end

def tries_to_post(forum)
 ...
end

def logs_in(user_name, password, forum=nil)
  ...
end

def posts_to_forum(forum)
  ...
end

# you get the picture
...

def is_reply_aarons_post?(reply, d_post)
  ...
end

end

def enter_site(name)
open_session do |session|
session.extend(ForumTestDSL)
session.name = name
yield session if block_given?
end
end
end

There is a ton of info on TDD out there, so you should have no trouble
getting really good advice on the subject.

Hope this helps!

C

4

Hi Nick,

I started using scaffold_resource (as opposed to scaffold) when I
started getting into REST. The scaffold_resource generator really does
a nice job of creating actions and tests for a RESTful implementation.
It also now adds the route to the routes.rb file, which it used to not
do. It is very convenient if you want to develop a RESTful
application. If you are not into REST, that’s cool. It just so
happens that REST was the new direction of Rails when I started
developing my new app, so I decided to give it a shot. I like it alot.
Unfortunately, the results of that generator are not documented in the
latest Agile book, so you kind of have to play around with it (make
sure you are running Edge or Rails 1.2 to see it in all its glory).

As far as what you are doing, you are basically doing the same thing as
you said, but you appear to be leaving out the Integration Test. No
problem there, of course, but I have found that writing an Intergration
Test first, in the manner in which I do above (with a DSL), helps me to
think about what my application needs to do from a user perspective.
That’s fantastic if you can keep all of that in your head, but I have
found it a lot easier on my short-term memory if I write this out first
so that I have a target in mind before I really begin coding. Not that
my way is any more right than anyone else’s, it just works for me.

C

5

i do something like redmotive, but i don’t use scaffold (don’t ask me
why, i don’t know :slight_smile: ), i create all by my own, and another difference
is that i create first the model and then tests and code, ok, it’s not
real TDD with develop first the model, but i think that it’s quite safe,
obviously i put in the model only what i need not, not things that MAYBE
i’ll need in the future (YAGNI)

6

redmotive wrote:

As far as what you are doing, you are basically doing the same thing as
you said, but you appear to be leaving out the Integration Test. No
problem there, of course, but I have found that writing an Intergration
Test first, in the manner in which I do above (with a DSL), helps me to
think about what my application needs to do from a user perspective.
That’s fantastic if you can keep all of that in your head, but I have
found it a lot easier on my short-term memory if I write this out first
so that I have a target in mind before I really begin coding. Not that
my way is any more right than anyone else’s, it just works for me.

i’m using integration tests and DSL too :slight_smile: and the possibility to create
more than one single session is great…I’m using also some functional
tests for controllers which do just things separately from other
controllers

7

I hear ya nick. Didn’t mean to impune the integrity of your testing,
you just didn’t mention it :wink: No offense intended. I have found that
writing my integration tests first has helped me keep my head wrapped
around the project, but that’s just because I need the extra focus.
You may be doing the same thing, I was just commenting on what you
wrote. Hope I didn’t offend you!

C

8

redmotive wrote:

I hear ya nick. Didn’t mean to impune the integrity of your testing,
you just didn’t mention it :wink: No offense intended. I have found that
writing my integration tests first has helped me keep my head wrapped
around the project, but that’s just because I need the extra focus.

yes :slight_smile:

Hope I didn’t offend you!

no :slight_smile: