Ask HN: How did you learn to properly build tests?

Don't.

I spent a lot of time trying to test "the right way" in Rails. There is none.

There is only a right way for you/your product/team/business right now. Do what works, and iterate and refactor when you find you spend too much time testing (that is, above 50%).

Source: I spend a lot of time working with testing at https://circleci.com

Testing is just a means to an end like the code you write. It creates a certain confidence level that your code is doing what it supposed to do based on the instructions you gave it.

Like the other dude said start with model tests because they are generally the easiest to work with.

Maybe start off with something basic. Write down a list of validation constraints that are necessary for the model you're testing in normal english.

Example, maybe you would do something like this for a Profile model.

  "expect error when first name is empty"
  "expect error when last name is empty"
  "expect error when e-mail address is empty"
  "expect error when e-mail address is an invalid format"

To get these working with the built in rails 4 test framework you just need to change them so they read:

  test "the description would go here" do
    # insert test code here
  end

I'll fill in 1 test for you and you can do the rest.

  test "expect error when first name is empty" do
    @profile = Profile.new
    @profile.first_name = ""
    refute @profile.save
  end

If you have no validations in your Profile model then this test will fail because it WILL save. So your goal is to make it pass. Now you would write your validation in the model as so:

  validates :first_name, presence: true

If you re-run the test it should pass now because active record will throw an error saying first name can't be blank. The test is designed to refute (ie. refuse) saving the model, which is the opposite of assert.

IMO just read through this: http://guides.rubyonrails.org/testing.html

The most important thing with testing is getting started. Over time you can build a better test infrastructure and tooling, but just start with it.

At Codeship we focus on functional tests first. We use Cucumber/Capybara/Selenium a lot to test the user facing functionality. This way we can be sure that the feature works on the highest level. For some parts you might need to go down to unit tests, but start with functional tests first.

If you want to get started with testing your system try the following:

Everyone in your team writes down his 7 most important workflows in the application from a users perspective and ranks them. Then put all of the workflows together and try to find the 7 most important ones your team agrees on. Then find a tool that helps you test those from a users perspective. Build the whole toolchain (Tetsing tools on every developer machine, Continuous Integration server/service, ...) so adding new tests is trivial.

Now there is no more excuse not to write tests.

For mocking take a look at a screencast we did a while ago:

http://blog.codeship.io/2013/06/11/testing-tuesday-9-stubbin...

But still the most important thing with testing is getting started and having the whole workflow in place. Even if there is just one test, getting to a point where it is easy to add new tests needs to be priority #1

take a simple piece of functionality, decide what you expect it to do, and write a test to check that it does it. It isn't complex - start with the simplest thing that works - minitest is integrated into Ruby, so use that. Write a single test to test a method on one of your models. Build it up from there.