def test_caller_is_not_full(self):
"""Test checking equivalence when the caller is not full."""
partially_filled = TruthTable('A xor B', fill_all=False)
partially_filled.fill(A=0)
with self.assertRaises(RequiresFullTableError):
partially_filled.equivalent_to('B xor A')
def helper_test_truth_table_fill_raises(self,
expr,
expected_exc_type=None,
**kwargs):
"""Helper for testing exception conditions when filling a table.
:param expr: The value to pass to the ``TruthTable`` constructor.
:type expr: BooleanExpression or str
:param expected_exc_type: The exception type expected to be raised.
:type expected_exc_type: Exception
:param kwargs: Keyword args to pass to the ``TruthTable`` constructor.
"""
did_catch = False
try:
t = TruthTable(expr, fill_all=False)
t.fill(**kwargs)
except expected_exc_type as e:
did_catch = True
except Exception as e:
traceback.print_exc()
self.fail('Received exception of type ' + type(e).__name__ +
' but was expecting type ' + expected_exc_type.__name__ +
'.')
did_catch = True
if not did_catch:
self.fail('No exception thrown.')
def test_attempt_to_fill_table_already_iteratively_filled(self):
"""Ensure that we cannot fill a table already iteratively filled."""
t = TruthTable('A nand B', fill_all=False)
t.fill(A=0)
t.fill(A=1)
with self.assertRaises(AlreadyFullTableError):
t.fill(A=0)
def test_other_is_not_full(self):
"""Test checking equivalence when the argument table is not full."""
full_table = TruthTable('A or B')
partially_filled = TruthTable('A or B', fill_all=False)
partially_filled.fill(B=1)
with self.assertRaises(RequiresFullTableError):
full_table.equivalent_to(partially_filled)
def test_is_full_iterative(self):
"""Test is_full attr when table is iteratively filled."""
t = TruthTable('A nand B xor C', fill_all=False)
self.assertFalse(t.is_full)
t.fill(A=0)
self.assertFalse(t.is_full)
t.fill(B=1)
self.assertFalse(t.is_full)
t.fill(C=0)
self.assertFalse(t.is_full)
t.fill(B=0)
self.assertTrue(t.is_full)
def test_table_iter_partially_filled(self):
"""Test iterating through a table that is partially filled."""
t = TruthTable('A xor C', fill_all=False)
t.fill(C=1)
count = 0
for inputs, result in t:
if count == 0:
self.assertEqual(inputs.A, False)
self.assertEqual(inputs.C, True)
self.assertEqual(result, True)
elif count == 1:
self.assertEqual(inputs.A, True)
self.assertEqual(inputs.C, True)
self.assertEqual(result, False)
count += 1
self.assertEqual(count, 2)
def test_table_getitem(self):
"""Test indexing the table to get its results."""
t = TruthTable('A or B', fill_all=False)
for i in range(4):
self.assertEqual(None, t[i])
t.fill(A=0)
self.assertEqual(t[0], False)
self.assertEqual(t[1], True)
t.fill()
self.assertEqual(t[0b00], False)
self.assertEqual(t[0b01], True)
self.assertEqual(t[0b10], True)
self.assertEqual(t[0b11], True)
t = TruthTable(from_values='1xx1')
self.assertEqual(t[0b00], True)
self.assertEqual(t[0b01], 'x')
self.assertEqual(t[0b10], 'x')
self.assertEqual(t[0b11], True)
def helper_test_truth_table_fill(self,
expr,
expected_table_str=None,
init_kwargs={},
**kwargs):
"""Helper to test filling a truth table.
:param expr: The value to pass to the ``TruthTable`` constructor.
:type expr: BooleanExpression or str
:param expected_table_str: The expected string representation of the
table.
:type expected_table_str: str
:param init_kwargs: A dict to pass as the kwargs to the ``TruthTable``
constructor.
:type init_kwargs: Dict
:param kwargs: Keyword args to pass to the fill method.
"""
t = TruthTable(expr, fill_all=False, **init_kwargs)
t.fill(**kwargs)
self.assertEqual(expected_table_str, str(t))
def test_is_full_from_single_fill_call(self):
"""Test is_full attr when filled via one fill() call."""
t = TruthTable('A nand B xor C', fill_all=False)
self.assertFalse(t.is_full)
t.fill()
self.assertTrue(t.is_full)
def test_attempt_to_fill_table_already_filled_on_init_from_expr(self):
"""Ensure that we cannot fill a table already filled from an expr."""
t = TruthTable('A or B')
with self.assertRaises(AlreadyFullTableError):
t.fill(A=0)
def test_attempt_to_fill_table_already_filled_from_values(self):
"""Ensure that we cannot fill() a table built from specified values."""
t = TruthTable(from_values='xxxx', ordering=['A', 'B'])
with self.assertRaises(AlreadyFullTableError):
t.fill(A=1)
