GSoC Week 5 recap

This week started out with some interesting discussions on the future Python structure of FreeCAD, over on the forums. This was especially salient as I have a bit of pain interacting with parts of the FreeCAD Python API and improvements to it would be a good long-term goal after finishing GSoC.

I decided that the TestPartDesignApp.py file I had been working in thus far needed splitting up, as I was cramming almost every new test into it. The new version of this file is a pretty nice indicator of the overall status of PartDesign test coverage.

I also added some basic tests for datum tools, covering simple creation scenarios. While exploring the 4th datum tool, ShapeBinder, I found a bug that causes a crash, so I will need to look into that shortly to see if it's an easy fix.

LinearPattern and PolarPattern got 6 new tests each, covering all the major variations of sketch- or primitive-based features.

Finally, I added one new test for each of the dressup features, Fillet, Chamfer, Draft, and Thickness.

Here's the pull request summarizing my work: https://github.com/FreeCAD/FreeCAD/pull/869