Sławosz Sławiński

How do I test? Spork and Emacs experience.

2011-08-11T00:00:00-07:00

Few weeks ago Ryan Bates created a screencast about testing. He uses Guard to run specs. Guard watches changes in files and may run appropriate specs files, which is very convenient. However, I have a little different way to run specs.

I do not always like to run full spec file, very often I need only to run one spec. To accomplish it very easily, I use few functions in my emacs, thanks to rinari mode emacs-rails mode:

rails-spec:run-this-spec – runs specs with current line as rspec line parameters. I use this command very very often (C-c C-c , shortcut)

rails-spec:run-current – runs all spec in current spec file or specs for file I actually edit. It works exactly like Guard, but I use it only when I need to (C-c C-c z .shortcut)

rails-spec:run-last – this function runs lately ran spec. It is great for TDD/BDD workflow, because with this I can run only one spec while I work on implementation in corresponding file (C-c C-c z l shortcut)

One of the most important things in TDD/BDD process is running specs after each change in code. Thus we run spec even hundreds times in (good) developer day. That is why specs should run very fast. We may say, that specs that run more than 10 seconds are distracting and may cause checking lastest rss/facebook/google+ news ;) Of course, I talk about single spec or single spec file, because it is normal that running entire test suite takes few minutes in large projects. But we run entire test suite before commit, or even we use CI.

Spork

Spork is a great tool for TDD/BDD. It is test server, it loads our app to memory and forks for spec you actually run. With this, spec runs immediately, without waiting for rails app bootstraping. It makes a big difference in specs speed. For example I did some benchmarks in Teambox project:

All spec file, without spork:
$ time (bundle exec rspec spec/models/user_spec.rb)

...............................................................................

Finished in 22.38 seconds
79 examples, 0 failures

real	0m35.714s

Single spec:

$ time (bundle exec rspec spec/models/user_spec.rb -l 90)

Run filtered using {:line_number=>90}
.

Finished in 0.54218 seconds
1 example, 0 failures

real	0m14.283s

And with Spork:
Whole spec file:

$ time (bundle exec rspec spec/models/user_spec.rb --drb)
...............................................................................

Finished in 24.55 seconds
79 examples, 0 failures

real	0m27.399s

And single spec with spork:

$ time (bundle exec rspec spec/models/user_spec.rb -l 90 --drb)
Run filtered using {:line_number=>90}
.

Finished in 0.51661 seconds
1 example, 0 failures

real	0m3.286s

Nice speed up! With spork, single spec lasts about 3 seconds. In other projects with longer bootstrap time, we save much more time!

To run rspec with spork, first run spork `spork` and then run any rspec with `--drb` option. Do not forget to add this option to spec runner in your editor. Before first run we have to bootstrap spork with command `spork --bootstrap`

My test flow:

1 I write spec
2 Run only this spec (rails-spec:run-this-spec in emacs)
3 It does not pass.
4 I write the code to make test pass
5 I run last spec (rails-spec:run-last in emacs)
6 If spec does not pass, back to point 4
7 Spec pass
8 Run spec for entire file (rails-spec:run-current) or even for the whole project.

I am hope that this note will usefull for You. I encourage you to run
your spec with spork and run them with your editor. It gives you much
more fun in TDD/BDD!

Add new resource with ajax

2011-04-26T00:00:00-07:00

In Railscast 258 Ryan Bates shows how to use Token Fields, javascript plugin which helps adding entries for many and many to many association. In this article I will exetend railscast and show you how to create not existing entries with ajax.

You can download application for this tutorial from github or use it on heroku to see how it works. I started with application created by Ryan in 258 episode.

To add authors we can go to /author/new url, but when we already on /books/new we rather want to render form with ajax. To render form we will use facebox, writen in jquery by Chris Wanstrath. So, simply download facebox from github, decompress and place facebox.css in public/stylesheets, facebox.js in public/javascripts and loading.gif and closelabel.png in public/images

Now, point write paths for images in public/javascripts/facebox.js:

loadingImage: '/images/loading.gif',
closeImage: '/images/closelabel.png',

and place stylesheet and javascript in our layout app/views/layouts/application.html.erb:

<%= stylesheet_link_tag "application", "token-input-facebook","facebox" %>
<%= javascript_include_tag :defaults, "jquery.tokeninput","facebox" %>

Now it is time to show form for new author resource on facebox.

Lets add link in app/views/books/_form.html.erb partial:

<%= f.label :author_tokens, "Authors" %><%= link_to 'Add new author', new_author_path, :remote => true %><br />

It looks like a normal link, but with one exception: it has a remote option, indicating, that we want perform an ajax request with this link. This is new way in Rails 3 to generate ajax request and I think it is great. It simply adds a html data-remote='true' attribute to our link. Javascript code located in public/javascripts/rails.js binds onclick event on such link. Whe link is clicked, an ajax request is performed to links url, in our case to new_author_path. So now, we have rewrite new method in AuthorsController, which is our link destination. You can read more about Rails 3 unobtrusive javascript in Simone Carletti blog.

With Rails it is so simple :) We had to add only a new template in js format, app/views/authors/new.js.erb. When we click link, method new will recognize that request is in js format and render js template. So now, in template we will write code, which will render new action on facebox:

$.facebox('<%= escape_javascript(render :template => 'books/new.html') %>');

Code above generate a form on facebox with app/views/books/new.html.erb template. We have to add write new.html to generate html. Much more often in rich ajax Rails application we use partials, but I would like to show how to achieve our goal with minimal effort.

If you would like to know more about using facebox, see public/javascripts/facebox.js. Every use case is described in this file.

Now, we want to send our form and create a new author.
Normaly, we can use

:remote => true

option in our form, but we only use remote form in facebox. So, let’s add data-remote attribute to ajax form in facebox. To do it, we will add following to app/views/books/new.js.erb:

$('#facebox form').data('remote','true');

This will add attribute data-remote='true' to our form, and with this attribute, public/javascripts/rails.js will process our form with ajax. After submiting, the request goes to method create in AuthorsController and is looking for js template. In this template, we need only close facebok. So, we create file app/views/authors/create.js.erb and write:

$(document).trigger('close.facebox');

Thus we would like to perform other actions in html and js request in this method, we use respond_to block and redirect on html format and render template on js format:

def create
  @author = Author.new(params[:author])
  if @author.save
    respond_to do |format|
      format.html { redirect_to @author, :notice => "Successfully created author." }
      format.js
    end
  else
    render :action => 'new'
  end
end

Now it works, but it need some more improvements. When @author instance cannot be save, we should render form again in facebox. In app/models/author.rb we add validadion:

validates :name, :presence => true

Now we cannot add new no-name author. When we try, we got validation error, which we want to show in facebox.

At first we need to change create action to use js format in else section:

def create
  @author = Author.new(params[:author])
  if @author.save
    respond_to do |format|
      format.html { redirect_to @author, :notice => "Successfully created author." }
      format.js
    end
  else
    respond_to do |format|
      format.html { render :action => 'new' }
      format.js
    end
  end
end

And finally change app/views/books/create.js.erb:

<% if @author.save %>
  $(document).trigger('close.facebox')
<% else %>
  $('#facebox .content').html('<%= escape_javascript(render :template => 'authors/new') %>')
  $('#facebox form').data('remote','true');
<% end %>

Now we have fully working form on facebox, with minimal changes in our code. We can do last small improvement, remove link ‘Back to List’. In facebox link is completely unnecessary. After checking source of app/views/authors/new.html.erb we simply need remove last <p> tag. In jQuery, it’s simple:

$('#facebox .content p:last').remove();

We add this line at the end app/views/authors/new.js.erb and at the end in else section in app/views/authors/create.js.erb. Now we are done.

See our application working on heroku, and check the
repo on github.
All changes you can see in cf13adacdff595059dc6eba0fcb33c0204ad6714

I hope this tutorial will be helpfull for You. Any feedback is welcome.

Run single test case to speed up development

2010-09-29T00:00:00-07:00

When you use common TestUnit (maybe with great gem Shoulda) or RSpec, you may speed up development by running only single test case.
In TestUnit, run test file with `-n` switch:

ruby -n "name_of_test_method" path/to/test_file.rb

or use regexp:

ruby -n "/name of test method/" path/to/test_file.rb

Regexp is very convinient when you work with shoulda.

In Rspec, you can use `-e`:

rspec -e 'name of pattern' path/to/spec_file.rb

Or maybe you would like to install autotest or autospec for Rspec?

Business seconds - my first gem

2010-08-16T00:00:00-07:00

In June, I have released my first gem, business seconds It is very simple extension for business time
In my project I needed to count business time in seconds between two time instances. At first, i forked business time, and start implementing my feature, but this is on not todo list in its README. So, I wrote it in separate gem, which has business time in dependencies

I wish my work will help some of You. Enjoy!