Porting SafeClipAssembeCoadd from HSC to LSST left that functionality without a unit test. Currently AssembleCoadd is tested from within tests/testCoadds.py. This test does not call AssembleCoadd directly however. The actual code pertaining to assembling a coadd exists within python/lsst/pipe/tasks/mocks/mockCoadd.py. This called from testCoadds, and is used to build and coadd synthetic images from known psfs amongst other things. This should be expanded to test both AssembleCoadd and SafeClipAssembleCoadd, possibly with some sort of argument to the function call. It is important to keep testing both methods of generating a coadd.