documentation/content/developer/tutorials/unit_tests.rst

===================================
Safeguard your code with unit tests
===================================

.. important::
   This tutorial is an extension of the :doc:`getting_started` tutorial. Make sure you have
   completed it and use the `estate` module you have built as a base for the exercises in this
   tutorial. Fetch the branch `{BRANCH}-core` from the `technical-training-solutions
   <https://github.com/odoo/technical-training-solutions/tree/{BRANCH}-core>`_ repository if you
   want to start from a clean base.

**Reference**:
`Odoo's Test Framework: Learn Best Practices <https://www.youtube.com/watch?v=JEIscps0OOQ>`__
(Odoo Experience 2020) on YouTube.

Writing tests is a necessity for multiple reasons. Here is a non-exhaustive list:

* Ensure code will not be broken in the future
* Define the scope of your code
* Give examples of use cases
* It is one way to technically document the code
* Help your coding by defining your goal before working towards it

Running Tests
=============

Before knowing how to write tests, we need to know how to run them.

.. code-block:: console

  $ odoo-bin -h
  Usage: odoo-bin [options]

  Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit

  [...]

  Testing Configuration:
    --test-file=TEST_FILE
                        Launch a python test file.
    --test-enable       Enable unit tests.
    --test-tags=TEST_TAGS
                        Comma-separated list of specs to filter which tests to
                        execute. Enable unit tests if set. A filter spec has
                        the format: [-][tag][/module][:class][.method] The '-'
                        specifies if we want to include or exclude tests
                        matching this spec. The tag will match tags added on a
                        class with a @tagged decorator (all Test classes have
                        'standard' and 'at_install' tags until explicitly
                        removed, see the decorator documentation). '*' will
                        match all tags. If tag is omitted on include mode, its
                        value is 'standard'. If tag is omitted on exclude
                        mode, its value is '*'. The module, class, and method
                        will respectively match the module name, test class
                        name and test method name. Example: --test-tags
                        :TestClass.test_func,/test_module,external  Filtering
                        and executing the tests happens twice: right after
                        each module installation/update and at the end of the
                        modules loading. At each stage tests are filtered by
                        --test-tags specs and additionally by dynamic specs
                        'at_install' and 'post_install' correspondingly.
    --screencasts=DIR   Screencasts will go in DIR/{db_name}/screencasts.
    --screenshots=DIR   Screenshots will go in DIR/{db_name}/screenshots.
                        Defaults to /tmp/odoo_tests.

  $ # run all the tests of account, and modules installed by account
  $ # the dependencies already installed are not tested
  $ # this takes some time because you need to install the modules, but at_install
  $ # and post_install are respected
  $ odoo-bin -i account --test-enable
  $ # run all the tests in this file
  $ odoo-bin --test-file=addons/account/tests/test_account_move_entry.py
  $ # test tags can help you filter quite easily
  $ odoo-bin --test-tags=/account:TestAccountMove.test_custom_currency_on_account_1

Integration Bots
================

.. note:: This section is only for Odoo employees and people that are contributing to
  `github.com/odoo`. We highly recommend having your own CI otherwise.

When a test is written, it is important to make sure it always passes when modifications are
applied to the source code. To automate this task, we use a development practice called
Continuous Integration (CI). This is why we have some bots running all the tests at different
moments.
Whether you are working at Odoo or not, if you are trying to merge something inside `odoo/odoo`,
`odoo/enterprise`, `odoo/upgrade` or on odoo.sh, you will have to go through the CI. If you are
working on another project, you should think of adding your own CI.

Runbot
------

**Reference**: the documentation related to this topic can be found in
`Runbot FAQ <https://runbot.odoo.com/doc>`__.

Most of the tests are run on `Runbot <https://runbot.odoo.com>`__ every time a commit is pushed on
GitHub.

You can see the state of a commit/branch by filtering on the runbot dashboard.

A **bundle** is created for each branch. A bundle consists of a configuration and
batches.

A **batch** is a set of builds, depending on the parameters of the bundle.
A batch is green (i.e. passes the tests) if all the builds are green.

A **build** is when we launch a server. It can be divided in sub-builds. Usually there are builds
for the community version, the enterprise version (only if there is an enterprise branch but you
can force the build), and the migration of the branch.
A build is green if every sub-build is green.

A **sub-build** only does some parts of what a full build does. It is used to speed up the CI
process. Generally it is used to split the post install tests in 4 parallel instances.
A sub-build is green if all the tests are passing and there are no errors/warnings logged.

.. note::
  * All tests are run regardless of the modifications done. Correcting a typo in an error message or
    refactoring a whole module triggers the same tests. All modules will be installed as well. This means
    something might not work even if the Runbot is green, i.e. your changes depend on a module that the
    module the changes are in doesn't depend on.
  * The localization modules (i.e. country-specific modules) are not installed on Runbot (except
    the generic one). Some modules with external dependencies can also be excluded.
  * There is a nightly build running additional tests: module operations, localization, single
    module installs, multi-builds for nondeterministic bugs, etc.
    These are not kept in the standard CI to shorten the time of execution.

You can also login to a build built by Runbot. There are 3 users usable: `admin`, `demo` and
`portal`. The password is the same as the login. This is useful to quickly test things on different
versions without having to build it locally. The full logs are also available; these are used for
monitoring.

Robodoo
-------

You will most likely have to gain a little bit more experience before having the rights to summon
robodoo, but here are a few remarks anyways.

Robodoo is the guy spamming the CI status as tags on your PRs, but he is also the guy that kindly
integrates your commits into the main repositories.

When the last batch is green, the reviewer can ask robodoo to merge your PR (it is more
a `rebase` than a `merge`). It will then go to the mergebot.

Mergebot
--------

`Mergebot <https://mergebot.odoo.com>`__ is the last testing phase before merging a PR.

It will take the commits in your branch not yet present on the target, stage it and rerun the tests
one more time, including the enterprise version even if you are only changing something in
community.

This step can fail with a `Staging failed` error message. This could be due to

* a nondeterministic bug that is already on the target. If you are an Odoo employee, you can check
  those here: https://runbot.odoo.com/runbot/errors
* a nondeterministic bug that you introduced but wasn't detected in the CI before
* an incompatibility with another commit merged right before and what you are trying to merge
* an incompatibility with the enterprise repository if you only did changes in the community repo

Always check that the issue does not come from you before asking the merge bot to retry: rebase
your branch on the target and rerun the tests locally.

Modules
=======

Because Odoo is modular, the tests need to be also modular. This means tests are defined in
the module that adds the functionality you are adding in, and tests cannot depend on functionality
coming from modules your module doesn't depend on.

**Reference**: the documentation related to this topic can be found in
:ref:`Special Tags<reference/testing/tags>`.

.. code-block:: python

  from odoo.tests.common import TransactionCase
  from odoo.tests import tagged

  # The CI will run these tests after all the modules are installed,
  # not right after installing the one defining it.
  @tagged('post_install', '-at_install')  # add `post_install` and remove `at_install`
  class PostInstallTestCase(TransactionCase):
      def test_01(self):
          ...

  @tagged('at_install')  # this is the default
  class AtInstallTestCase(TransactionCase):
      def test_01(self):
          ...


If the behavior you want to test can be changed by the installation of another module, you need to
ensure that the tag `at_install` is set; otherwise, you can use the tag `post_install` to speed up
the CI and ensure it is not changed if it shouldn't.

Writing a test
==============

**Reference**: the documentation related to this topic can be found in
`Python unittest <https://docs.python.org/3/library/unittest.html>`__
and :ref:`Testing Odoo<reference/testing>`.

Here are a few things to take into consideration before writing a test

* The tests should be independent of the data currently in the database (including demo data)
* Tests should not impact the database by leaving/changing residual data. This is usually done by
  the test framework by doing a rollback. Therefore, you must never call ``cr.commit`` in a test
  (nor anywhere else in the business code).
* For a bug fix, the test should fail before applying the fix and pass after.
* Don't test something that is already tested elsewhere; you can trust the ORM. Most of the tests
  in business modules should only test the business flows.
* You shouldn't need to flush data into the database.

.. note:: Remember that ``onchange`` only applies in the Form views, not by changing the attributes
  in python. This also applies in the tests. If you want to emulate a Form view, you can use
  ``odoo.tests.common.Form``.

The tests should be in a ``tests`` folder at the root of your module. Each test file name
should start with `test_` and be imported in the ``__init__.py`` of the test folder. You shouldn't
import the test folder/module in the ``__init__.py`` of the module.

.. code-block:: bash

  estate
  ├── models
  │   ├── *.py
  │   └── __init__.py
  ├── tests
  │   ├── test_*.py
  │   └── __init__.py
  ├── __init__.py
  └── __manifest__.py

All the tests should extend ``odoo.tests.common.TransactionCase``. You usually define a
``setUpClass`` and the tests. After writing the `setUpClass`, you have an `env` available in the
class and can start interacting with the ORM.

These test classes are built on top of the ``unittest`` python module.

.. code-block:: python

  from odoo.tests.common import TransactionCase
  from odoo.exceptions import UserError
  from odoo.tests import tagged

  # The CI will run these tests after all the modules are installed,
  # not right after installing the one defining it.
  @tagged('post_install', '-at_install')
  class EstateTestCase(TransactionCase):

      @classmethod
      def setUpClass(cls):
          # add env on cls and many other things
          super(EstateTestCase, cls).setUpClass()

          # create the data for each tests. By doing it in the setUpClass instead
          # of in a setUp or in each test case, we reduce the testing time and
          # the duplication of code.
          cls.properties = cls.env['estate.property'].create([...])

      def test_creation_area(self):
          """Test that the total_area is computed like it should."""
          self.properties.living_area = 20
          self.assertRecordValues(self.properties, [
             {'name': ..., 'total_area': ...},
             {'name': ..., 'total_area': ...},
          ])


      def test_action_sell(self):
          """Test that everything behaves like it should when selling a property."""
          self.properties.action_sold()
          self.assertRecordValues(self.properties, [
             {'name': ..., 'state': ...},
             {'name': ..., 'state': ...},
          ])

          with self.assertRaises(UserError):
              self.properties.forbidden_action_on_sold_property()

.. note:: For better readability, split your tests into multiple files depending on the scope of the
  tests. You can also have a Common class that most of the tests should inherit from; this common
  class can define the whole setup for the module. For instance, in
  `account <{GITHUB_PATH}/addons/account/tests/common.py>`__.

.. exercise:: Update the code so no one can:

  - Create an offer for a sold property
  - Sell a property with no accepted offers on it

  and create tests for both of these cases. Additionally check that selling a property that can
  be sold is correctly marked as sold after selling it.


.. exercise:: Someone keeps breaking the reset of Garden Area and Orientation when you uncheck the
  Garden checkbox. Make sure it doesn't happen again.

  .. tip:: Tip: remember the note about `Form` a little bit above.