Fuzzer for CS258 Sudoku Checker

sudoku_fuzzer.py

def fuzzer_for_sudoku_checker(sudoku_checker):
    """ given `sudoku_checker` a sudoku checker function, attempts to ferret out common issues with checking
    for valid input.  Raises AssertionError s if the function fails to conform to expectations"""
    try:
        illegal = (0, [], range(10), [range(10), range(10), 0, range(10), 1, range(10), range(10), range(10), range(10)])
        valid_row = range(1, 10)
        invalid = ([[1]*9] * 9, [valid_row * 8] + [range(2, 11)])
        for s in illegal:
            res = sudoku_checker(s) 
            assert res is None, "Failed to detect that {s} was illegal. Returned {res} instead of `None`".format(s=s, res=res)
        for s in invalid:
            res = sudoku_checker(s)
            assert res is False, "Failed to return False for invalid sudoku {s}. Returned {res} instead of `False`".format(s=s, res=res)
    except AssertionError:
        raise
    except Exception as e:
        raise AssertionError("Raised error type {etype} with msg {emsg}.".format(etype=type(e), emsg=str(e)))

I added it to the repo I made for this (put an argparse wrapper around it so you could run it more easily) jtratner/sudoku-fuzzer-udacity@9017adf . It's a neat case ;)