Unit tests

A couple of functions were implemented to automate the unit test if the module follows the same design as pyquickhelper:

• The unit tests must be in <root>/_unittests.

• There are only one level of subfolders inside this folder, all names are prefixed by ut_.

• Tests files starts with test_.

• Unit test must inherits from :py:`unittest:TestCase` or :py:class:`ExtTestCase <pyquickhelper.pycode.unittestclass.ExtTestCase>` which adds a couple of *assert methods.

One function is used to prints information but is disabled when running the whole list of unit tests: fLOG. Another function is often used to create a temporary folder relative to the test file: get_temp_folder. The option is prefered because it lets temporary data available close to the code. It is easier to check if something went wrong. Plus temporary files or folder are not always fully cleaned by the operating system. A limit is sometimes reached and produces an error difficult to interpret if the developer is not aware of that limit. Some behavior might change on continuous integration. Function is_travis_or_appveyor returns the continuous integration system used. Finally, testing notebooks is important when there are many and that’s an important part of teachings. The following function test_notebook_execution_coverage tests a notebooks assuming it is in folder <root>/_docs/notebooks. It also keeps track of the number of executed cells and reports on the coverage.