Meta Bates

Testing in Ruby on Rails is incredibly easy. I mean stupidly easily. So easy that if you’re not doing it, you are a very, very bad developer and should re-evaluate your career choices. (Yes, I believe in testing that much!) One thing that is not all that easy, however, is object creation and populating your test database. Five years ago when I first started working with Rails the only options we had to get data into the database were fixtures, or hastily written ‘factory’-esque methods custom to each application.

Fixtures, for those who don’t know, are YAML files that contain YAML-ized versions of objects that then get loaded into the test database when you run your test suite. These objects can then be pulled back from the database during your tests. Sounds great, doesn’t it? Well, not everybody thinks so. One of the biggest problems with fixtures is they can very quickly get out of control. Keeping track of all the different scenarios your tests needs can get very confusing and frustrating to deal with.

So how do we fix this problem? Well, most developers have turned to using factories. Factories allow us to quickly build the data we need for each test, now the building of the data you need for your test is right there in a setup or before method. Easy to manage and keep track of. Now there are a plethora of different factory libraries meant to make this task nicer, a few of the popular ones are Factory Girl, Machinist, and Object Daddy. The problem with this approach, however, is that it can slow down your tests as you are building database objects for nearly every test, and as we all know, object creation and database inserting can be expensive.

So, what can we do to help solve both of these problems? Well, we can use both of these technologies. Together. Yeah, that’s right I’m saying you should use fixtures as well as factories. Sound crazy? Not really. Let me explain.

Most Rails applications have most, if not all, of their functionality behind a login. So whenever we’re testing some controller action that sites behind a login we need a user to login with. If we were using factories we would have a setup or before method that would create a new User object and save it to the database, and it would do that for every variant of the test, as well as every other test in our suite that needs a user object.

Why not, create one user object and use that repeatedly through our tests? What I like to do is stick one or two users in my fixtures, so that they’re there whenever I need one. I like to do this with most of my major models. Then, when I need to have some custom scenarios, I can break out the factories and build those custom scenarios.

So what does this achieve? Well, I’ve sped up my tests by already having a few objects in the database, and not having to create them (and roll them back) with each single test. I’ve also cleaned up my tests significantly by eliminating a lot of setup and/or before methods where these objects were being created. I’ve also eliminated the biggest problems with fixtures, that they can get overwhelming, because we are only keeping one or two objects in them and using factories for the rest.

I hoped this helped you to understand that we don’t have to throw the baby out with the bath water when it comes to fixtures and factories, we can use both. Not go forth and test! Test like your life depends on it (because it does!!).

Ruby 1.9(.2) is an amazing language to develop applications in. It’s faster, more powerful, cleaner, and a huge improvement over Ruby 1.8.x. Because of those reasons every Ruby developer should move to this exciting new version of our language.

Enter CoverMe.

History

While working on a Ruby 1.9/Rails 3 project, and loving everything about it (except for the lack of RCov), I came across a post by Aaron Patterson (of Nokogiri fame). In this post he quickly outlined a very basic coverage tool using the new built-in Coverage module in Ruby 1.9.

After spending a morning playing with it, I was quickly able to grow the idea into something useful for the project. Later that day the company I was consulting for (BiddingForGood.com), and in particular their chief architect, Stuart Garner, told me to take a day or two and clean it up and release it for the world to use, and so here it is.

Features

Here is a brief overview of the features of CoverMe:

Index Page

• Sortable column headers (File, Lines, Lines of Code, Tested %).
• Searching/filtering by file name.
• Filtering by coverage percent.
• Color coded list of files to quickly see which ones are 100% covered, > 90% covered, or less than 90% covered.
• Large color coded average coverage percent, for quick reference.

Detail Page

• Line by line coverage report
• Color coded lines to quickly see which lines where executed and which ones were not.
• Side by side viewing with the corresponding test/spec file (if one exists).

See the README file for more information on installation and usage.

Thanks

I would just quickly like to give another quick thanks to Aaron Patterson for pointing out the Coverage module in Ruby 1.9 and inspiring this, hopefully, helpful little gem. Also another big thanks to Stuart Garner for pushing me to package this up and release it to the world.

Screenshots

Five years ago I left the world of contracting and reentered the world of the full time employee, and I enjoyed every minute of it (well, almost). Now fast forward five years and I find myself once again at a crossroads. Do I continue on as an FTE or do I become a contractor, and play the field, so to speak? Looks like I’m going to go with the hired gun route for a little while, but that’s not really the point of this post.

During the past week or so I’ve spoken with many great companies and people. I’ve been fortunate enough to have a high degree of interest in what I can bring to the table. During those discussions I talked with a really nice guy at a what seems to be a really cool company, I won’t name names, because this isn’t about either the person or the company, but rather something the engineer said during our phone conversation that got me to thinking.

“We don’t have any tests because I couldn’t convince the company to allocate the time for them.” That statement really hung with me. After I got off the phone I started thinking really hard about that statement, and all I could think of was how testing is not an option and people shouldn’t need to be convinced to have time allocated to them.

As developers it is our responsibility to insist on testing. Always include testing in your time estimates. Never give the client (or your company) an option that includes a time estimate without testing. If a feature takes 2 days to code and a day to write tests, then your estimate is 3 days, never 2. You should never say, “Well, I can get it done in two days if I don’t write any tests.” That’s just an unacceptable thing to say. What you should be saying is, “That feature will take three days to code”.

I don’t feel I should sit here and tell you all the reasons why you should test, you should know them already, and frankly, they’re all very obvious! But, if you need a few bullet points to ‘convince’ your client, here are a few:

• Less bugs – The more tests you have the less bugs you will have. It’s just a fact. You won’t have 100% bug free code, that’s a nearly impossible goal, but you highly reduce the likely hood that as soon as you get your code into production your users will find all the breaking points of your code.
• Better maintainability, means faster feature turn around – When you have a large test suite it means adding, updating, or even removing features because a whole lot easier, which means it SAVES time! Why? Simple, you don’t have to go through and manually test every aspect of your code to make sure you didn’t break something elsewhere by adding that validation, or by refactoring that bit of code, etc… That translates into real $ savings.
• Test driven development saves time – this isn’t quite the same as my last bullet point. Imagine, if you will, you are writing a four step wizard in your application. If you write a few test scripts using something like Cucumber first before you write your code you can simply keep re-running those to make sure your code is working. If you don’t have those test scripts written then you continually have to keep going to a browser and entering all the information in each of the steps so you can test something in step four. Which one do you think takes longer, having a few test scripts you can run, or manually going through the four page wizard each time you make a change?
• It’s an investment – thinking of having test scripts like owning a house. When you don’t have tests and you just keep testing in the browser or the command line what you are doing is a kin to “renting”. There is money being spent, but at the end of the day you have nothing to show for it. You’ve spent hours “testing”, but tomorrow when you come in you have to do it all over again. When you spend those hours writing tests you are actually “buying” something. You have something to show for that time and money you’ve spent. Tomorrow, next week, next month, next year, those scripts will still be there, they’ll still be working for you, giving  you a return on your investment.

Well, I hope I have hopefully made a case to you the engineer as to why you should insist on testing. It’s the right thing to do, for you, for your application and for you client. If if anyone tries to give you grief about it, send them my way, I’ll sort em out!

Now that I’m back on track with DataMapper, I’ve got migration support for both it and ActiveRecord just about done. In addition to the actual rake task, db:migrate (btw), I had to set up a good way to test rake tasks, something I’ll share at a later date, but needless to say it’s included with Mack. I also had to deal with the pain in the ass-ness of dealing with two VERY different ORMs, in the same test system! Let me tell you, that sucked!

Good news is that things seem to be working, at least going in the ‘up’ direction anyway. I still need to write the ‘down’ direction revert stuff. Hopefully, that shouldn’t take too long now that I have a good way of testing the task and the migration stuff.

Unfortunately, I feel as though as soon as I release this stuff, which should be by the end of this weekend, DataMapper 0.9.0 will be out, and I’ll have to re-write most of the DataMapper stuff because the API is changing so radically. I guess I’ll just have to deal with that when the time comes.

In the meantime I’ll let y’all know when migrations are done and out there in the wild.

I’ve been asked by people why I’m not using spec tests to test Mack. I’m currently using just plain old regular unit tests for my tests. It’s a good question, but not really a valid one, I think. Should it matter what type of tests I’m using as long as I’m testing? Tests are tests. The framework you use to do your tests is moot as long as the tests you write are good, solid tests.

I jumped on the spec test bandwagon about a year or so ago. I forced my whole team to start writing in nothing but spec tests. The team, is still not impressed. If I were to tell them we weren’t using spec tests anymore, they would be EXTREMELY happy with that.Spec tests are certainly prettier than ‘regular’ tests. I’ll give you that. They are more ‘human readable’. With that said I find assert_equal to be fairly easy to read.

So why do I use regular tests, and not spec tests? A couple of reasons. First, they’re there and built right in to Ruby, ready to go, no new gems or syntax to learn. They’re fast. They are faster than spec tests. I see it everyday at work. I can also, and this one is HUGE, run just a single test or a regex’d series of tests. I really love that last bit. I have yet to find a way to do that, easily, with spec tests.

Again, how people write tests doesn’t really matter so much to me, it’s just that they write them. Testing is too easy in Ruby, there’s just no reason for not writing them.