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Thomas De Schampheleire

tests: fix assertion rewriting in some tests with pytest-3.0.0+

Since pytest 3.0.0, asserts present in modules that are not directly seen by
pytest as 'test modules', are no longer rewritten to have improved
reporting, unless they are explicitly marked as up-for-rewriting.
Rationale from pytest upstream:

However since we do not want to test different bytecode then you will
run in production this hook only re-writes test modules themselves as
well as any modules which are part of plugins. Any other imported module
will not be re-written and normal assertion behaviour will happen.

This is e.g. the case for asserts in files like
kallithea/tests/api/api_base.py and kallithea/tests/models/common.py.

See
http://doc.pytest.org/en/latest/changelog.html#id13
http://doc.pytest.org/en/latest/writing_plugins.html#assertion-rewriting

This commit registers all modules below kallithea.tests for assert
rewriting, but note that asserts in kallithea/tests/__init__.py itself are
not rewritten as kallithea.tests is already imported when the register
statement is encountered.
Moving the register statement to kallithea/__init__.py would fix that, but
even then asserts in kallithea/tests/__init__.py seem not to be rewritten
(let alone the issue that we do not want a pytest dependency enforced in
kallithea/__init__.py which is also used in production).
Moving the code from kallithea/tests/__init__.py to a proper module, as
suggested by Mads Kiilerich, solves that problem.

=======================
Database schema changes
=======================

Kallithea uses Alembic for :ref:`database migrations <upgrade_db>`
(upgrades and downgrades).

If you are developing a Kallithea feature that requires database schema
changes, you should make a matching Alembic database migration script:

1. :ref:`Create a Kallithea configuration and database <setup>` for testing
   the migration script, or use existing ``development.ini`` setup.

   Ensure that this database is up to date with the latest database
   schema *before* the changes you're currently developing. (Do not
   create the database while your new schema changes are applied.)

2. Create a separate throwaway configuration for iterating on the actual
   database changes::

    paster make-config Kallithea temp.ini

   Edit the file to change database settings. SQLite is typically fine,
   but make sure to change the path to e.g. ``temp.db``, to avoid
   clobbering any existing database file.

3. Make your code changes (including database schema changes in ``db.py``).

4. After every database schema change, recreate the throwaway database
   to test the changes::

    rm temp.db
    paster setup-db temp.ini --repos=/var/repos --user=doe --email doe@example.com --password=123456 --no-public-access --force-yes
    paster repo-scan temp.ini

5. Once satisfied with the schema changes, auto-generate a draft Alembic
   script using the development database that has *not* been upgraded.
   (The generated script will upgrade the database to match the code.)

   ::

    alembic -c development.ini revision -m "area: add cool feature" --autogenerate

6. Edit the script to clean it up and fix any problems.

   Note that for changes that simply add columns, it may be appropriate
   to not remove them in the downgrade script (and instead do nothing),
   to avoid the loss of data. Unknown columns will simply be ignored by
   Kallithea versions predating your changes.

7. Run ``alembic -c development.ini upgrade head`` to apply changes to
   the (non-throwaway) database, and test the upgrade script. Also test
   downgrades.

   The included ``development.ini`` has full SQL logging enabled. If
   you're using another configuration file, you may want to enable it
   by setting ``level = DEBUG`` in section ``[handler_console_sql]``.

The Alembic migration script should be committed in the same revision as
the database schema (``db.py``) changes.

See the `Alembic documentation`__ for more information, in particular
the tutorial and the section about auto-generating migration scripts.

.. __: http://alembic.zzzcomputing.com/en/latest/


Troubleshooting
---------------

* If ``alembic --autogenerate`` responds "Target database is not up to
  date", you need to either first use Alembic to upgrade the database
  to the most recent version (before your changes), or recreate the
  database from scratch (without your schema changes applied).