pytest-locker 0.2.6

Used to lock object during testing. Essentially changing assertions from being hard coded to asserting that nothing changed

PyTest-Locker

PyTest-Locker: The fasted way to check for unexpected behaviour changes

The test-locker can be used to "lock" data during a test. This means that rather than having to manually specify the expected output you lock the data when it corresponds to expected behaviour, afterwards you only need to check if the data has not changed.

Data can be a response, but state and previous calls can also be represented as data. This gives you the option to " lock" just about anything that your software does using this library.

Why use PyTest-Locker

• Time efficient: No need to hard code expected responses. (Especially usefull for data heavy unittests)

• Easy to verify changes:

  • Seperates the logic of the test from the expected values.
  • The lock files (containing the expected values), and changes to them, are easy to interpret. This makes it really simple to evaluate changes during testing, in commits and in pull request.

Install

run pip install pytest-locker

Usage

Configuring the project and writing your first test.

1. Add from pytest_locker import locker to your conftest.py file
2. To access the locker by adding it to the method parameters i.e. def test_example(locker)

4. Use locker.lock(your_string, optional_name) to lock the data (of-course you can also lock other types). 5. Ensure that the pytest rootdir is fixed. See the pytest customize documentation for all the options (one is adding a pytest.ini to the root folder) 6. Ensure that .pytest_locker/ is synced via git, to ensure that you, your team, and your CI/CD pipelines are working with the same data.

And you're all set!

Accepting the current behavior and checking fo changes in this behavior

There are two modes based on for locking. The first is

1. When user input is allowed, i.e. when running pytest with --capture no or -s

   When user input is allowed and the given data does not correspond to the data in the lock the user is prompted if the new data should be stored or if the tests should fail.

2. When user input is captured which is default behavior for pytest

   If user input is not allowed the tests will automatically fail if the expected lock file does not exist or if the data does not correspond to the data in the lock file.

The Locker class

You can also use pytest_locker.Locker (i.e. the class of which the locker fixture returns an instance) directly to create fixtures that locks a (non-string) object without needing to turn the object into a string it.

You can also use pytest_locker.Locker as a basis for locking more complex objects than just strings. One example is pytest_locker.JsonLocker (and the corresponding pytest_locker.json_locker fixture)

Examples

For example of use look at the tests in repr-utils.