Did you know that a unit test should have three basic blocks?
1. Arrange / Given
2. Act / When
3. Assert / Then
Let's quickly go over them so you get a better idea.
A thread.
1. Arrange / Given
2. Act / When
3. Assert / Then
Let's quickly go over them so you get a better idea.
A thread.
1. Arrange / Given
This is where you set up everything you need to trigger the logic you want to test.
No matter whether you initialize input variables or specify the result you later expect. This is where this logic belongs.
1/10
This is where you set up everything you need to trigger the logic you want to test.
No matter whether you initialize input variables or specify the result you later expect. This is where this logic belongs.
1/10
'Given' is a term coming from behavior-driven design where human-readable "user stories" are used to describe your expectations.
You can read it as: "Given this input or setup...".
2/10
You can read it as: "Given this input or setup...".
2/10
2. Act / When
This is the block where you actually call the logic you want to test.
Calling a function or a method on a class and storing the result (if necessary) belongs here.
This block should usually be pretty short.
If it's too long, your test might do too much.
3/10
This is the block where you actually call the logic you want to test.
Calling a function or a method on a class and storing the result (if necessary) belongs here.
This block should usually be pretty short.
If it's too long, your test might do too much.
3/10
'When' as a term also comes from behavior-driven design.
You can read it as: "When a user triggers this logic...".
4/10
You can read it as: "When a user triggers this logic...".
4/10
3. Assert / Then
This is the block where you test your expectations.
The name of the block already describes that you will see assertions here.
This is also the block where exceptions should arise if a test fails.
5/10
This is the block where you test your expectations.
The name of the block already describes that you will see assertions here.
This is also the block where exceptions should arise if a test fails.
5/10
'Then' is also a term from behavior-driven design.
You can read it as: "Then this is what should happen...".
6/10
You can read it as: "Then this is what should happen...".
6/10
4. Why test structure matters
-> Readability and somehow a form of standardization <-
If all unit tests are structured similarly, it is way easier for you to understand what exactly goes on within a specific test case.
7/10
-> Readability and somehow a form of standardization <-
If all unit tests are structured similarly, it is way easier for you to understand what exactly goes on within a specific test case.
7/10
We, as humans, tend to love patterns. We can recognize patterns, and we like to remember them because they make our lives easier.
If you structure all your tests this way, or even your whole team does it, you'll have an easier time reading your tests.
8/10
If you structure all your tests this way, or even your whole team does it, you'll have an easier time reading your tests.
8/10
And tests have one important trait: They are great for understanding the code they actually test.
Tests usually show usage of functions, methods, APIs, or whatever it is.
They are a form of documentation.
Taking care of this documentation definitely benefits you.
9/10
Tests usually show usage of functions, methods, APIs, or whatever it is.
They are a form of documentation.
Taking care of this documentation definitely benefits you.
9/10
5. Thread end
That's it for this thread.
I hope you found something useful! 🙏🏼
If there is anything you'd like to add, please respond to the first tweet so more people can see it.
And if you like content like this, consider following me (@oliverjumpertz) for more! 💛
10/10
That's it for this thread.
I hope you found something useful! 🙏🏼
If there is anything you'd like to add, please respond to the first tweet so more people can see it.
And if you like content like this, consider following me (@oliverjumpertz) for more! 💛
10/10
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