Add initial testing section with naming convetion

README.md

@@ -562,6 +562,68 @@ class CourseCreateApi(
 
 All of code above can be found in `utils.py` in this repository.
 
+## Testing
+
+In our Django projects, we split our tests depending on the type of code they represent.
+
+Meaning, we generally have tests for models, services, selectors & APIs / views.
+
+The file structure usually looks like this:
+
+```
+project_name
+├── app_name
+│   ├── __init__.py
+│   └── tests
+│       ├── __init__.py
+│       ├── models
+│       │   └── test_some_model_name.py
+│       ├── selectors
+│       │   └── test_some_selector_name.pyy
+│       └── services
+│           ├── __init__.py
+│           └── test_some_service_name.py
+└── __init__.py
+```
+
+### Naming conventions
+
+We follow 2 general naming conventions:
+
+* The test file names should be `test_the_name_of_the_thing_that_is_tested.py`
+* The test case shoud be `class TheNameOfTheThingThatIsTestedTests(TestCase):`
+
+For example if we have:
+
+```python
+def a_very_neat_service(*args, **kwargs):
+    pass
+```
+
+We are going to have the following for file name:
+
+```
+project_name/app_name/tests/services/test_a_very_neat_service.py
+```
+
+And the following for test case:
+
+```python
+class AVeryNeatServiceTests(TestCase):
+    pass
+```
+
+For tests of utility functions, we follow a similiar pattern.
+
+For example, if we have `project_name/common/utils.py`, then we are going to have `project_name/common/tests/test_utils.py` and place different test cases in that file.
+
+If we are to split the `utils.py` module into submodules, the same will happen for the tests:
+
+* `project_name/common/utils/files.py`
+* `project_name/common/tests/utils/test_files.py`
+
+We try to match the stucture of our modules with the structure of their respective tests.
+
 ## Inspiration
 
 The way we do Django is inspired by the following things: