[Tutor] Puzzling case of assertRaises not running properly

[angela ebirim]

Hi,

Learning about how to write tests in Python and have a query.

*#bill.py*
class Bill(object):

   def tax(self, total):
     tax = float(total * 0.05)
     return round(tax, 2)

   def check_input(self, seat1, app1):
     try:
        seat1 = float(seat1)
        app1 = float(app1)
     except ValueError:
         print "Not a float"
     return (seat1, app1)

   def bill(self, seat1, app1):
     (seat1, app1) = self.check_input(seat1, app1)
     tax = self.tax(seat1 + app1)
     total = seat1 + app1 + tax
     return (total, tax)

if __name__=='__main__':
     bill = Bill()
     (total, tax) =  bill.bill(2,3)
     print("tax $%.2f" % tax)
     print("total charge for meal $%.2f" % total)

*#bill_test.py*

class BillTest(unittest.TestCase):
    def setUp(self):
      self.bill = Bill()

    def test_bill_pay_3_4(self):
      self.assertEqual((7.35, 0.35), self.bill.bill(3,4))

    def test_input_not_float_raises_ValueError(self):
      with self.assertRaises(ValueError):
          self.bill.check_input("aa","bb")

if __name__=='__main__':
   unittest.main()

I'm using Python 2.7.

When I run the test doing python bill_test.py -v, I get the following
result:-

test_bill_pay_3_4 (__main__.BillTest) ... ok
test_input_not_float_raises_ValueError (__main__.BillTest) ... Not a float
FAIL

======================================================================
FAIL: test_input_not_float_raises_ValueError (__main__.BillTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "billa_test.py", line 13, in test_input_not_float_raises_ValueError
    self.bill.check_input("aa","bb")
AssertionError: ValueError not raised

----------------------------------------------------------------------
Ran 2 tests in 0.003s

FAILED (failures=1)

Can someone please tell me what I'm doing wrong?

Many thanks