Module xinject.pytest_plugin

Auto-loaded common fixtures for helping with unit-testing.

"""
Auto-loaded common fixtures for helping with unit-testing.

.. important:: Very Important!  Don't import this module!
    pytest should automatically import this via it's plugin mechanism.
    If you import any of the fixtures below manually, you may get something like this:

    `ValueError: duplicate 'xinject_test_context'`

    You should be able to use any of these fixtures without importing them.
    This is accomplished via the setup.py file in xinject, it tells pytest about the
    `xinject.pytest_plugin` module, so it can load them automatically.


    For `xinject.pytest_plugin.xinject_test_context` fixture it's self... it's an auto-use fixture,
    so it's automatically used anyway.

    I would probably just get the current context like you normally would
    (via `xinject.context.XContext.grab`), rather than use this fixture directly
    in your unit-test.
"""
import pytest


@pytest.fixture(autouse=True)
@pytest.mark.order(-1300)
def xinject_test_context():
    """
    Will blank-out the app and root contexts by allocating new containers
    for the root contexts.

    This means that, the first time a thread asks/needs a XContext, one will be created lazily
    after the unit test starts since we removed all of them from the global state.

    This fixture is also using the `autouse=True` feature of pytest, to ensure this always runs.
    You don't need to use it directly,
    simply call `xinject.context.XContext.current` like you normally would if you need the
    current context during your unit-test.

    After the unit test is finished, this auto-use fixture will clean up the state again.

    It's important that this is the first fixture that runs,
    so we marked it with a -1300 fixture order, helping to ensure that it runs first.

    There is nothing special about the number per-se,
    it's just sufficiently low, at least compared to all of our own fixtures in our own codebase.
    """

    # Want to keep global-module slate clean, import stuff we need privately.
    from .context import (
        XContext, _setup_blank_app_and_thread_root_contexts_globals
    )

    # Ensure we have a blank slate for the unit-test.
    # This will allocate brand new, blank global app+thread root-contexts.
    _setup_blank_app_and_thread_root_contexts_globals()

    # Yield the current thread-root context as the fixture-value.
    yield XContext.grab()

    # Ensure app+thread root-contexts do not have leftover dependency objects from unit test.
    _setup_blank_app_and_thread_root_contexts_globals()

Functions

def xinject_test_context()

Will blank-out the app and root contexts by allocating new containers for the root contexts.

This means that, the first time a thread asks/needs a XContext, one will be created lazily after the unit test starts since we removed all of them from the global state.

This fixture is also using the autouse=True feature of pytest, to ensure this always runs. You don't need to use it directly, simply call XContext.current() like you normally would if you need the current context during your unit-test.

After the unit test is finished, this auto-use fixture will clean up the state again.

It's important that this is the first fixture that runs, so we marked it with a -1300 fixture order, helping to ensure that it runs first.

There is nothing special about the number per-se, it's just sufficiently low, at least compared to all of our own fixtures in our own codebase.

Expand source code

@pytest.fixture(autouse=True)
@pytest.mark.order(-1300)
def xinject_test_context():
    """
    Will blank-out the app and root contexts by allocating new containers
    for the root contexts.

    This means that, the first time a thread asks/needs a XContext, one will be created lazily
    after the unit test starts since we removed all of them from the global state.

    This fixture is also using the `autouse=True` feature of pytest, to ensure this always runs.
    You don't need to use it directly,
    simply call `xinject.context.XContext.current` like you normally would if you need the
    current context during your unit-test.

    After the unit test is finished, this auto-use fixture will clean up the state again.

    It's important that this is the first fixture that runs,
    so we marked it with a -1300 fixture order, helping to ensure that it runs first.

    There is nothing special about the number per-se,
    it's just sufficiently low, at least compared to all of our own fixtures in our own codebase.
    """

    # Want to keep global-module slate clean, import stuff we need privately.
    from .context import (
        XContext, _setup_blank_app_and_thread_root_contexts_globals
    )

    # Ensure we have a blank slate for the unit-test.
    # This will allocate brand new, blank global app+thread root-contexts.
    _setup_blank_app_and_thread_root_contexts_globals()

    # Yield the current thread-root context as the fixture-value.
    yield XContext.grab()

    # Ensure app+thread root-contexts do not have leftover dependency objects from unit test.
    _setup_blank_app_and_thread_root_contexts_globals()