'''
Tests for fpformat module
Nick Mathewson
'''
from test.test_support import run_unittest, import_module
import unittest
fpformat = import_module('fpformat', deprecated=True)
fix, sci, NotANumber = fpformat.fix, fpformat.sci, fpformat.NotANumber
StringType = type('')
# Test the old and obsolescent fpformat module.
#
# (It's obsolescent because fix(n,d) == "%.*f"%(d,n) and
# sci(n,d) == "%.*e"%(d,n)
# for all reasonable numeric n and d, except that sci gives 3 exponent
# digits instead of 2.
#
# Differences only occur for unreasonable n and d. <.2 wink>)
class FpformatTest(unittest.TestCase):
def checkFix(self, n, digits):
result = fix(n, digits)
if isinstance(n, StringType):
n = repr(n)
expected = "%.*f" % (digits, float(n))
self.assertEqual(result, expected)
def checkSci(self, n, digits):
result = sci(n, digits)
if isinstance(n, StringType):
n = repr(n)
expected = "%.*e" % (digits, float(n))
# add the extra 0 if needed
num, exp = expected.split("e")
if len(exp) < 4:
exp = exp[0] + "0" + exp[1:]
expected = "%se%s" % (num, exp)
self.assertEqual(result, expected)
def test_basic_cases(self):
self.assertEqual(fix(100.0/3, 3), '33.333')
self.assertEqual(sci(100.0/3, 3), '3.333e+001')
def test_reasonable_values(self):
for d in range(7):
for val in (1000.0/3, 1000, 1000.0, .002, 1.0/3, 1e10):
for realVal in (val, 1.0/val, -val, -1.0/val):
self.checkFix(realVal, d)
self.checkSci(realVal, d)
def test_failing_values(self):
# Now for 'unreasonable n and d'
self.assertEqual(fix(1.0, 1000), '1.'+('0'*1000))
self.assertEqual(sci("1"+('0'*1000), 0), '1e+1000')
# This behavior is inconsistent. sci raises an exception; fix doesn't.
yacht = "Throatwobbler Mangrove"
self.assertEqual(fix(yacht, 10), yacht)
try:
sci(yacht, 10)
except NotANumber:
pass
else:
self.fail("No exception on non-numeric sci")
def test_REDOS(self):
# This attack string will hang on the old decoder pattern.
attack = '+0' + ('0' * 1000000) + '++'
digs = 5 # irrelevant
# fix returns input if it does not decode
self.assertEqual(fpformat.fix(attack, digs), attack)
# sci raises NotANumber
with self.assertRaises(NotANumber):
fpformat.sci(attack, digs)
def test_main():
run_unittest(FpformatTest)
if __name__ == "__main__":
test_main()