How to test without mocking
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How to test without mocking
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Re: How to test without mocking
#2 The problem is when IOService has edge cases. When building the mock, does it address the edge cases? When you want to find bugs by testing, the tests need to test the real world. So to work, the mock for IOService needs to model the edge cases of IOService. Does it? Does the developer know they need to model the edge cases, or the mock is not helping with finding bugs? Do you even know the edge cases of IOService? When IOService is a database service, does your mock work for records that do not exist? Or return more than one record?
Not to say you should mock everything. Of course having proper integration tests is also important, but articles like these will rarely tell you to have a good balance between them, and will instead tell you that something is correct and something else is wrong. You should do what makes sense for that specific case and exercise your abilities to make the right choice, and not blindly follow instructions you read in a blog post.
Re: How to test without mocking
#3I've been doing this stuff (software) for a very long time and if it hadn't been invented by others, I'd never have thought of Mocking. It's that stupid of an idea. When I first came across it used in anger in a large project it took me a while to get my head around what was going on. When the penny dropped I remember a feeling of doom, like I had realized I was in The Matrix. Don't work there, and don't work with mock-people any more.
Re: How to test without mocking
#4Your mock object is a joke; that object is mocking you. For needing it.
~ Rich Hickey
Re: How to test without mocking
#5The problem is that mocks are normally used to avoid testing services/outside code.
For example making a wrapper around a message system if you don't mock, it tests both your code and the message system.
However the the overhead of keeping the mocking system up to date is a pain in the balls.
Re: How to test without mocking
#6The golden rule was to only mock your own code. Make a facade around the framework class using an interface and mock that if needed to decouple your tests. Then write integration tests against your implementation of the interface. The moment you mock other people’s code you have brittle tests.
Re: How to test without mocking
#7Tests are a tool for you, the developer. They have good effects for other people, but developers are the people that directly interact with them. When something fails, it's a developer that has to figure out what change they wrote introduced a regression. They're just tools, not some magic incantation that protects you from bugs.
I think the author might be conflating good tests with good enough tests. If IOService is handled by a different team, I expect them to assure IOService behaves how it should, probably using tests. The reason we're mocking IOService is because it's a variable that I can remove, that makes the errors I get from a test run MUCH easier to read. We're just looking at the logic in one module/class/method/function. It's less conceptually good to mock things in tests, since I'm not testing the entire app that we actually ship, but full no-mocks E2E tests are harder to write and interpret when something goes wrong. I think that makes them a less useful tool.
The thing I do agree on, is assuming your mocks should only model the happy path. I'd say if something can throw an exception, you should at least include that in a mock. (as a stubbed method that always throws) but making the burden of reimplementing your dependancies mandatory, or relying on them in tests is going to mean you write less tests, and get worse failure messages.
Like everything, it depends eh?
Re: How to test without mocking
#8I've been doing this stuff (software) for a very long time and if it hadn't been invented by others, I'd never have thought of Mocking. It's that stupid of an idea. When I first came across it used in anger in a large project it took me a while to get my head around what was going on. When the penny dropped I remember a feeling of doom, like I had realized I was in The Matrix. Don't work there, and don't work with mo…
With containerization it’s very quick to spin up test dependencies as well as part of your CICD. Why mock calls to a datastore when it’s super easy to spin up an ephemeral postgresql instance to test on?
Re: How to test without mocking
#9I've been doing this stuff (software) for a very long time and if it hadn't been invented by others, I'd never have thought of Mocking. It's that stupid of an idea. When I first came across it used in anger in a large project it took me a while to get my head around what was going on. When the penny dropped I remember a feeling of doom, like I had realized I was in The Matrix. Don't work there, and don't work with mo…
I don't like mocking either, but there are periodically situations where I've found it useful. Sometimes there is a complex system (whether of your own design or not) that isn't amenable to integration/e2e testing, and the interesting parts can't be easily unit tested due to external or tightly coupled dependencies.
Of course you can always pick it apart and refactor so it can be unit tested, but sometimes the effort required makes mocking look pretty appealing.
Re: How to test without mocking
#10The problem is when IOService has edge cases. When building the mock, does it address the edge cases? When you want to find bugs by testing, the tests need to test the real world. So to work, the mock for IOService needs to model the edge cases of IOService. Does it? Does the developer know they need to model the edge cases, or the mock is not helping with finding bugs? Do you even know the edge cases of IOService? W…
100% agree. Maybe you should be the amazing cto.
Context always matters.