Kata premise is completely flawed: Why does partition(101, 50) expect [50, 51] only? [101] is also a valid result, since sqrt(2n)-(3minsize) is negative in this case.

Error messages are not very useful:

Has invalid result

Shouldn't use test.expect()

stated it explicitly in description now

corrected in description

I would definitively specify that the sum of the output should be the value.

I really like it otherwise, short but pleasant.

test.expect(len(partition(50, 1)) >= 7, "length should be 7 at least")

According to the description, the list must be [strictly] longer that 7.