Testing HTML strings returned from helpers

I heart assert_select. But when we’re testing helpers using ActionView::TestCase, we don’t have a response object available, and assert_select is usually used in the context of a response object. So you might think you can just pass a string of html to assert_select, but unfortunately that doesn’t work. So what’s a Rails developer to do?

You could use regular expressions. You could also vomit on your monitor and stab yourself in the eye. Luckily, there are a couple alternatives.

RSpec. I’m not really an RSpec guy, but it apparently does have support for testing html from helpers.

The helper_me_test plugin from Brian Landau of Viget Labs seems like an elegant and flexible alternative. It takes advantage of the fact that assert_select accepts an optional HTML::Node object as its first argument. I definitely recommend taking a look at that plugin, especially if you prefer hpricot. The plugin seems to have been spawned as a consequence of this thread on the Rails Lighthouse.

Ultimately I’ve chosen to write something custom, but really lightweight, which involves simply opening the String class and adding a to_node method that returns the string as an HTML::Node. I’ve gisted an example. It’s not as elegant as helper_me_test, but it’s so little code that I’ve decided it’s best for the particular app I’m working on.

Hopefully this helps someone.

How I stopped slamming github with submodules

github has been slow at times over the past couple months, which isn’t surprising considering how quickly the service became popular. I found myself getting a bit frustrated at how long it would take to add submodules to new projects, until I figured out that you can do this from a local git repo.

Let’s take Rails as an example. Let’s say you have a local git clone of the Rails repo at ~/rails/edge. To add a submodule without slamming github: git submodule add ~/rails/edge vendor/rails. After that I manually modify the Rails submodule url property in .gitmodules, like so:


[submodule "vendor/rails"]
path = vendor/rails
url = git://github.com/rails/rails.git


After that, git pull from vendor/rails will just get the diffs from github, which should be pretty quick. And you’re a happier and more considerate github citizen. :)

Merb Day Atlanta

I attended Merb Day Atlanta this past Saturday. The day consisted of a tutorial before lunch, and talks afterward, culminating in Merb lead developer Yehuda Katz‘s closing keynote (slides).

The tutorial was given by Merbists Michael Ivey and Matt Todd. Considering there were 60+ people following a live coding session, it went pretty well. I heard a few complaints about the depth of the material, but I think they covered the basics well and got as in-depth as they could given the time and environment constraints. One reason it went well was their use of Git. In fact, there was a git repository setup for the entire conference. Each speaker was free to put their code, notes, slides, and whatever else into the repo, and with a simple `git pull` there it was on my local machine. I don’t know if Merb Day was the first conference to use Git and Github like this, but it’s a great idea and I hope every conference I attend from now on does the same.

Myself and a couple others also setup repos for Merb Day. Mine has my notes and the code from the tutorial, which I preferred to type in myself. I learn better that way than just staring at someone else’s code. My notes are probably not that helpful, as the slides for most presentations are available in the main git repo. One thing to note is that schulty’s repo has haml translations of the tutorial erb views and sass translations of the stylesheets.

The best part of the conference for me was being seated next to Yehuda. I was able to ask him a couple questions, and more importantly I got to listen in as others approached him with questions between sessions. I’d also like to acknowledge that the conference was well-organized and the facilities were top-notch. Before the conference I had some issues getting a room, but conference organizer Luigi Montanez steered me in the right direction and got me a discount to boot. Even today, 3 days after the conference Luigi sent me a followup email to make sure I got my Merb In Action book. So, thanks Luigi. As far as the facilities, they were comfortable, the network worked well, the power strips were plentiful, and the drinks and snacks were all free. Georgia Tech Convention Center FTW.

If I have any criticism of the conference at all, it’s that there wasn’t a talk about DataMapper. But the content that was presented was well-done and I encourage you to poke through the slides and code available in the main conference git repository.

Okay, so enough of the lovefest. What about Merb itself?

Merb’s codebase is beautiful and well-documented. If you want to learn Ruby by looking at some solid open source code, my first recommendation would be Merb. Just go look at it. I feel pretty confident that with source like that, I won’t be so dependent upon other documentation when I get stuck.

I’m intrigued by the modular approach Merb takes. While there are some definite benefits to a full-stack, opinionated approach to web frameworks, I think the modular approach forces you into decoupling and providing clean APIs. (It all comes back to clean code, doesn’t it?)

Even though I haven’t really had a need for JRuby, I’m psyched that Yehuda and the Merb team take JRuby integration seriously. I don’t ever want to go back to coding Java for a living, but there are several exciting things happening in the JVM space. (Clojure anyone?). I’d definitely feel a bit cornered in my future career choices if my favorite technology didn’t run on the JVM.

The focus on speed is another Merb strong point. If I had a dollar for every time Yehuda mumbled “because it’s faster that way” during the conference, I’d have walked out of there at least ten bucks richer.

Finally, I’d like to address the whole Rails vs. Merb thing. Rails has been way too good to me these past few years. I’m a happier person and a better programmer because of Ruby and Rails. I still write Rails code every day and getting out of bed to do it hasn’t become a chore yet. There’s no such thing as Merb without Rails trailblazing the path. But, like all software, Rails has its pain points. Merb was initiated as an attempt to address some of those pain points. And that pushback has in turn improved Rails. Competition is, on the whole, a good thing. Merb inspires Rails to become thread safe. Sinatra and Camping inspire Merb to provide a very-flat single file app option. The ecosystem improves for all of us. I’m one of the many developers that came for the Rails and stayed for the Ruby, and I’m still pretty excited about what I see in the future of Ruby web development.

Rails development dependency loading issue

If you ever encounter this error in Rails:

“A copy of ApplicationHelper has been removed from the module tree but is still active!”

a simple workaround that worked for me was to add this to config/environments/development.rb:

load 'application_helper.rb'

I’m really not sure why I started hitting this error in an app I’ve been developing for a few months now. It seems to be related to a Singleton class. I don’t really have the time or desire to dig into Rails dependency loading to figure out the exact root cause, but the above LOC will manually reload the helper. From what I can tell in my limited research, there be dragons with Rails dependency loading, especially in the development environment.

Hello World!

A while back I hit the magic button and deleted all old posts on this blog. So, this is a relaunch of sorts. I intend to keep things technical here and let my tumblelog and twitter account handle the rest of my online detritus.

I’ve never really fell into a comfortable blogging groove, but I am going to do my best to rectify that. I love to write and communicate, but doing that well takes significant time and effort, especially when it comes to technical writing. I certainly don’t want to have a blog just to rant (that’s what Twitter is for!) or be part of the echo chamber (again, Twitter ;). So, I’m setting the bar kind of high for myself here. As if I need something else to feel pressured about.

Here’s hoping that someone finds what I write to be interesting and useful.