C-Mock | C Mock is Google Mock | Mock library

You can try something like this :

I'm not really sure what happened and why but I tried doing this on my rails container and I was no longer receiving the said error.

1. docker-compose run --rm bash
2. cd to project directory
3. bundle install

Looks like you're running into compatibility issues trying to use the latest version of the activerecord-import gem at the time of writing (released in October 2020) with activerecord 3.2.22.5 (released in September 2016). You do mention it's a rails 3.2.15 app but you're not using activerecord 3.2.15 which is confusing.

Try using activerecord-import 0.4.1 (released in July 2013) and activerecord 3.2.15 which should be compatible with rails 3.2.15.

In this case, before is actually before(:each), which is reusing the client_double and attributes you defined with the #let helper method. The let commands make those variables functionally equivalent to instance variables within the scope of the described object, so you aren't really testing freshly-created objects in each example.

Some alternatives include:

1. Refactor to place all your setup into before(:each) without the let statements.
2. Make your tests DAMP by doing more setup within each example.
3. Set up new scope for a new #describe, so your test doubles/values aren't being reused.
4. Use your :before, :after, or :around blocks to reset state between tests, if needed.

Since you don't show the actual class or real code under test, it's hard to offer specific insights into the right way to test the object you're trying to test. It's not even clear why you feel you need to test the collaborator object within a unit test, so you might want to give some thought to that as well.

Try updating your Gemfile to use json@1.8.2 instead of 1.8.1 - according to this thread Ruby 2.2.x is incompatible with json 1.8.1.

1.8.2 should be functionally similar and not affect any of your other dependencies.

You can also run bundle update json to let bundler try to fix it for you - but that may put you at a much later version than 1.8.2, I'm not sure.

No harm in trying a couple things and reverting your changes.

Solved by following the steps at https://stackoverflow.com/a/48312139/13217139 then re-installed the gem with gem install ffi -- --enable-system-libffi

Clean and rebuild

Soooooo,

I decided to go the dependency injection route. I really wanted to figured out how to mock the Gpio class without going the DI route just to figure it out, but at this point I just want to move foward.

So, dependency injection should be relatively easy right? Well, there's a bit of a snag with the dependency injection I was trying to do. I need to use the Gpio class as a constructor, not as an instance of Gpio.

In my BotController class I'm using the Gpio class to construct distinct instances of Gpio:

But with typescript, if you inject a class into a constructor (and I assume methods), you don't get the class constructor, you get an instance of the class. To inject a constructor instead of an instance, you need to use typeof:

Because according to the docs:

Here we use typeof Greeter, that is “give me the type of the Greeter class itself” rather than the instance type. Or, more precisely, “give me the type of the symbol called Greeter,” which is the type of the constructor function.

So now, I can mock the pigpio module and pass the mocked Gpio class in to be used as a constructor and the test does not blow up.

Tomorrow, moving forward!!!!

Have you ever scaled to the top of a mountain, stood on the peak tired but triumphant, and then looked down at the other side to see an escalator??

After posting this answer and going to bed I woke up to another super helpful comment from Estus:

You missed __esModule: true for jest.mock, you need it for named exports . Without it, a mock is treated as CommonJS module, which translates to ESM default export. See jestjs.io/docs/en/…

I hadn't seen anything about this in the docs, but when you look at the given section of the API reference:

So, with this new knowledge I was able to go back and change all of my BotController code back to it's original state, removing the dependency injection:

And in my test I added the __esModule: true setting back into the mock's implementation, passed back my Gpio class mock with the digitalWrite mock and my test passes:

I feel like I've been through the ringer, but in the end I'm happy to know several ways of tackling this problem. Hopefully the detail in this question and answer will save someone else the headache.

The reason why you get a test_helper.rb file instead of an spec_helper.rb file is because rails comes with Minitest as the default framework to write the tests, on the other hand rails has the possibility to use other testing frameworks as Rspec installing it as you mentioned.

In the case, for example of https://github.com/chrisalley/pundit-matchers it says that is a set of RSpec matchers for testing Pundit, so in this case you need to use Rspec in order to use this matchers. If you want to keep using Minitest you probably have to look to a similar option of matchers but for Minitest.

Wether if Rspec or Minispec is better depends on the different aspects of the project and the organizations but both options are powerful options to write tests.

There are more articles in Stack Overflow related to the configuration in Rspec and Minitest, for example:

How is spec/rails_helper.rb different from spec/spec_helper.rb? Do I need it?.

You can also take a look at the documentation for both Rspec and Minitest.

There are also tools to transform your Minitest files to Rspec files like:

https://github.com/jaredbeck/minitest_to_rspec