def test_dfas_with_provided_strings(self):
"""
Uses the strings provided in the Yaml files.
Errors are raised if an accept string is rejected or a
reject string is accepted
"""
for test in self.tests:
accept_strings = test.yaml["accept_strings"]
reject_strings = test.yaml["reject_strings"]
# Make sure there are actually strings defined
self.assertTrue(len(accept_strings) > 0)
self.assertTrue(len(reject_strings) > 0)
for input_string in accept_strings:
# Run them through the DFA, raise exception if it doesn't accept
if not dfa_accepts(test.dfa, input_string):
raise(UnexpectedRejection(test.yaml["description"], input_string, test.yaml["regex"]))
for input_string in reject_strings:
# Run them through the DFA, raise exception if it accepts
if dfa_accepts(test.dfa, input_string):
raise(UnexpectedAccept(test.yaml["description"], input_string, test.yaml["regex"]))
def main(args):
description, dfa = load_dfa(args.dfa_yaml)
print("Loaded DFA: {}".format(description))
print("Input string: {}".format(args.input_string))
validate_dfa(dfa)
accepts = dfa_accepts(dfa, args.input_string)
if accepts:
print("DFA accepts string '{}'".format(args.input_string))
sys.exit(0)
else:
print("DFA rejects string '{}'".format(args.input_string))
sys.exit(1)
def main(args):
description, dfa = load_dfa(args.dfa_yaml)
print("Loaded DFA: {}".format(description))
print("Input string: {}".format(args.input_string))
validate_dfa(dfa)
accepts = dfa_accepts(dfa, args.input_string)
if accepts:
print("DFA accepts string '{}'".format(args.input_string))
sys.exit(0)
else:
print("DFA rejects string '{}'".format(args.input_string))
sys.exit(1)
def test_dfas_with_generated_strings(self):
"""
This test uses the exrex module to generate strings from a regular expression
Each DFA yaml file includes it's own regular expression that describes the
language.
"""
# Skip this test if exrex isn't installed
try:
import exrex
except ImportError:
msg = "Skipping exrex based test because it's missing. Do 'pip install exrex'"
print(msg)
self.skipTest(msg)
for test in self.tests:
# Take at most MAX_GENERATED strings from the exrex generator
for input_string in islice(exrex.generate(test.yaml["regex"]), self.MAX_GENERATED):
# Run them through the DFA, raise exception if it doesn't accept
if not dfa_accepts(test.dfa, input_string):
raise(UnexpectedRejection(test.yaml["description"], input_string, test.yaml["regex"]))
def test_rejects_string_with_unrecognized_character(self):
self.assertFalse(dfa_accepts(self.dfa, "ababaQ"))
def test_throws_error(self):
with self.assertRaises(InvalidDFA) as e:
dfa_accepts(self.invalid_dfa, "bbbbb")
error = "Something went wrong when attempting transition from state '1' on input 'b'"
self.assertTrue(error in str(e.exception))
def test_rejects_string(self):
input_string = "abba"
self.assertFalse(dfa_accepts(self.dfa, input_string))
def test_accepts_string(self):
input_string = "abbaa"
self.assertTrue(dfa_accepts(self.dfa, input_string))