I recently learned, Rspec + Capybara (I’m new to testing things). And I’ve been testing some new models I’ve created. Now, I was thinking of adding the title column to my Post model. It’s not a hard task, and I’ve done it many times before. But I realized that it’s going to take me some work updating the spec files (e.g. post, post pages, user, user pages, factories, sample_data, etc.).
Is testing in this case, a waste of time? Or it is a good practice to test absolutely everything?
I also wonder if testing gems is a waste of time as well? Since they’ve been probably already tested by their creators (the same for testing something taken from a reliable tutorial).
While the ruby community is known by its focus on testing, every case should be analyzed in context to figure out what the most cost-effective decisions are.
It is useful to think of tests as a technique to manage risk. If you don’t think that displaying titles/adding them to the database is a task that is error-prone, complex to perform, or that the cost of adding those tests is higher than the risk of eventually breaking something, them it might be wise to not do it.
That said, since you said that you are new to testing, I would recommend (if you are not time-constrained, of course) to try to take the idea to the extreme of testing absolutely everything, so that you can have an idea of how much of it adds value, and how much is waste of time.
You might want to take a look at this blog post from DHH, the creator of Rails, where he talks about that: Testing like the TSA
About testing gems, it is generally well-accepted that they shouldn’t be tested by your application tests, but by their creators. Most of the time you can simply assume that they work the ways they promise.