Since I cannot find any tests for this yet anywhere, how about testing numerically some of the more complicated relations? E.g. try

```
from sympy.utilities.randtest import test_numerically as tn
assert tn(besselj(S(5)/2, z), besselsimp(besselj(S(5)/2, z)))
```

Also, you might want to test that the expansion works e.g. for 5/2 (i.e. reduces to trig functons).