Make stub QgisInterface and MockMessageBar inherit real interfaces

[Joonalai]

This PR:

• Makes stub implementations of QgisInterface and QgsMessageBar to inherit their real parents
• Improves tests

Fixes #24, fixes #26.

[codecov-commenter]

Codecov Report

Attention: 577 lines in your changes are missing coverage. Please review.

Comparison is base (af7f77a) 57.77% compared to head (64ad100) 29.85%.

Files	Patch %	Lines
src/pytest_qgis/qgis_interface.py	3.79%	558 Missing ⚠️
src/pytest_qgis/mock_qgis_classes.py	58.13%	18 Missing ⚠️
src/pytest_qgis/pytest_qgis.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #54       +/-   ##
===========================================
- Coverage   57.77%   29.85%   -27.92%     
===========================================
  Files           7        7               
  Lines         495     1065      +570     
===========================================
+ Hits          286      318       +32     
- Misses        209      747      +538     

Flag	Coverage Δ
pytest	29.85% <7.53%> (-27.92%)	⬇️

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[Joonalai]

@LKajan, could you review this?

[alukach]

@Joonalai this looks great from an outsider's perspective. Any tips on what is needed to get this merged in?

[Joonalai]

@alukach I'm afraid that this PR is not going to be merged. Maybe theses issues should be fixed in some other way. I am no longer in an active role of developing this project but maybe @LKajan could give some more details on how to get these issues fixed.

[LKajan]

@alukach, @Joonalai,
Sorry for not responding to this PR earlier.

I think we should avoid bringing typing "stubs" of QGIS classes into this project. This would create an endless need to update the typing annotations for every new QGIS version. The QGIS package is already typed; users just need to add a py.typed file to the qgis package directory to use them.

However, there are parts of this PR that could be considered for merging. I'll take another look now that I have some more time.

[alukach]

The QGIS package is already typed; users just need to add a py.typed file to the qgis package directory to use them.

@LKajan The typing itself is a bit of a secondary feature, correct? The key value add of this PR is supporting realistic interactions with the qgis tooling generated by this plugin, correct? For example, I'm currently seeing errors when attempting to build out the menus in my plugin with the iface generated by the plugin:

        # Build plugin menu
>       plugin_menu = cast(QtWidgets.QMenu, self.iface.pluginMenu())
E       AttributeError: 'QgisInterface' object has no attribute 'pluginMenu'

How can I help you in terms of resolving issues like these with the plugin?

[LKajan]

@alukach, you are right that this would kind of solve the issue you're having. Still I wonder if this should be addressed probably by using mocking (using Mock from unittest.mock) instead of faking.

For your case, you could extend the faked QgisInterface as following:

@pytest.fixture(scope="session")
def qgis_iface(qgis_iface: QgisInterface):
    qgis_iface.pluginMenu=Mock()
    return qgis_iface