def test_constraint_repr(op):
"""Test the repr method of a constraint object.
"""
v = Variable('foo')
c = Constraint(v + 1, op)
assert op in repr(c)
def test_constraint_creation2():
"""Test for errors in Constraints creation.
"""
v = Variable('foo')
with pytest.raises(TypeError) as excinfo:
Constraint(1, '==')
assert "Expression" in excinfo.exconly()
with pytest.raises(TypeError) as excinfo:
Constraint(v + 1, 1)
assert "str" in excinfo.exconly()
with pytest.raises(ValueError) as excinfo:
Constraint(v + 1, '!=')
assert "relational operator" in excinfo.exconly()
def test_constraint_or_operator():
"""Test modifying a constraint strength using the | operator.
"""
v = Variable('foo')
c = Constraint(v + 1, '==')
for s in ('weak', 'medium', 'strong', 'required', strength.create(1, 1,
0)):
c2 = c | s
if isinstance(s, str):
assert c2.strength() == getattr(strength, s)
else:
assert c2.strength() == s
def test_constraint_creation():
"""Test constraints creation and methods.
"""
v = Variable('foo')
c = Constraint(v + 1, '==')
assert c.strength() == strength.required and c.op() == '=='
e = c.expression()
t = e.terms()
assert (e.constant() == 1 and len(t) == 1 and t[0].variable() is v
and t[0].coefficient() == 1)
assert str(c) == '1 * foo + 1 == 0 | strength = 1.001e+09'
for s in ('weak', 'medium', 'strong', 'required'):
c = Constraint(v + 1, '>=', s)
assert c.strength() == getattr(strength, s)
def test_constraint_or_operator():
"""Test modifying a constraint strength using the | operator.
"""
v = Variable('foo')
c = Constraint(v + 1, u'==')
for s in (u'weak', 'medium', 'strong', u'required',
strength.create(1, 1, 0)):
c2 = c | s
if isinstance(s, (type(''), type(u''))):
assert c2.strength() == getattr(strength, s)
else:
assert c2.strength() == s
with pytest.raises(ValueError):
c | 'unknown'
def test_constraint_creation(op):
"""Test constraints creation and methods.
"""
v = Variable('foo')
c = Constraint(v + 1, op)
assert c.strength() == strength.required and c.op() == op
e = c.expression()
t = e.terms()
assert (e.constant() == 1 and
len(t) == 1 and t[0].variable() is v and t[0].coefficient() == 1)
constraint_format = r'1 \* foo \+ 1 %s 0 | strength = 1.001e\+[0]+9' % op
assert re.match(constraint_format, str(c))
for s in ('weak', 'medium', 'strong', 'required'):
c = Constraint(v + 1, op, s)
assert c.strength() == getattr(strength, s)
# Ensure we test garbage collection.
del c
gc.collect()
def test_constraint_creation():
"""Test constraints creation and methods.
"""
v = Variable('foo')
c = Constraint(v + 1, '==')
assert c.strength() == strength.required and c.op() == '=='
e = c.expression()
t = e.terms()
assert (e.constant() == 1 and
len(t) == 1 and t[0].variable() is v and t[0].coefficient() == 1)
assert str(c) == '1 * foo + 1 == 0 | strength = 1.001e+09'
for s in ('weak', 'medium', 'strong', 'required'):
c = Constraint(v + 1, '>=', s)
assert c.strength() == getattr(strength, s)
def test_constraint_creation(op):
"""Test constraints creation and methods.
"""
v = Variable('foo')
c = Constraint(v + 1, op)
assert c.strength() == strength.required and c.op() == op
e = c.expression()
t = e.terms()
assert (e.constant() == 1 and
len(t) == 1 and t[0].variable() is v and t[0].coefficient() == 1)
constraint_format = '1 \* foo \+ 1 %s 0 | strength = 1.001e\+[0]+9' % op
assert re.match(constraint_format, str(c))
for s in ('weak', 'medium', 'strong', 'required'):
c = Constraint(v + 1, op, s)
assert c.strength() == getattr(strength, s)
# Ensure we test garbage collection.
del c
gc.collect()