Tadej Ciglarič

Can this be merged or should I add anything else?

> it keeps breaking in unexpected ways I am sorry for that, but the things I am changing touch practically entire library. I don't have perfect understanding of all the...

> I think these tests can all exist at the math level. I agree that would be preferable. What I am missing (or does it exist somewhere?) at the math...

AFIK expect_ad is not used on tests of all functions. The framework for distributions only tests distributions. Here I would need to test all functions in stan math that can...

I amde a python script that searches mix tests of functions: ``` import os fun_folder = r"F:\Users\tadej\Programming\bstatcomp\stan-math\stan\math\prim\fun" funs = os.listdir(fun_folder) test_folder = r"F:\Users\tadej\Programming\bstatcomp\stan-math\test\unit\math\mix\fun" tests = os.listdir(test_folder) all_mat = [] no_test...

> There's really no way to test that things work with expressions in general because there are lots of different expression types. Actually the number is infinite. Checking that it...

I don't think we need the whole combinatorics thing. What we need is to check that every argument of every overload can be expression (this can be the same test...

Actually there are multiple options. One is the one you found. Another one is using plain_type_t (you need reference to avoid copy if it is already a matrix): ``` const...

I am mostly finished with those tests. I figured we need to run these not only when there is some change in math functions, but also when support for new...

The PR for testing framework is up: https://github.com/stan-dev/stan/pull/2933