def test_juggle_error_is_raised_when_constraints_can_not_be_resolved():
solver = Solver()
a = Variable()
b = Variable()
c = Variable(40, strength=REQUIRED)
d = Variable(30, strength=REQUIRED)
solver.add_constraint(EqualsConstraint(a, b))
solver.add_constraint(EqualsConstraint(a, c))
solver.add_constraint(EqualsConstraint(b, d))
with pytest.raises(JuggleError):
solver.solve()
def test_notify_for_nested_constraint():
events = []
solver = Solver()
a = Variable()
b = Variable()
nested = EqualsConstraint(a, b)
multi = MultiConstraint(nested)
solver.add_constraint(multi)
solver.solve()
def handler(constraint):
events.append(constraint)
solver.add_handler(handler)
a.value = 10
solver.solve()
assert multi in events
assert nested not in events
def test_min_size(self):
"""Test minimal size constraint"""
solver = Solver()
v1 = Variable(0)
v2 = Variable(10)
v3 = Variable(10)
c1 = EqualsConstraint(a=v2, b=v3)
c2 = LessThanConstraint(smaller=v1, bigger=v3, delta=10)
solver.add_constraint(c1)
solver.add_constraint(c2)
# check everyting is ok on start
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
# change v1 to 2, after solve it should be 0 again due to LT
# constraint
v1.value = 2
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
# change v3 to 20, after solve v2 will follow thanks to EQ
# constraint
v3.value = 20
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(20, v2)
self.assertEquals(20, v3)
# change v3 to 0, after solve it shoul be 10 due to LT.delta = 10,
# v2 should also be 10 due to EQ constraint
v3.value = 0
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
def test_min_size(self):
"""Test minimal size constraint"""
solver = Solver()
v1 = Variable(0)
v2 = Variable(10)
v3 = Variable(10)
c1 = EqualsConstraint(a=v2, b=v3)
c2 = LessThanConstraint(smaller=v1, bigger=v3, delta=10)
solver.add_constraint(c1)
solver.add_constraint(c2)
# check everyting is ok on start
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
# change v1 to 2, after solve it should be 0 again due to LT
# constraint
v1.value = 2
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
# change v3 to 20, after solve v2 will follow thanks to EQ
# constraint
v3.value = 20
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(20, v2)
self.assertEquals(20, v3)
# change v3 to 0, after solve it shoul be 10 due to LT.delta = 10,
# v2 should also be 10 due to EQ constraint
v3.value = 0
solver.solve()
self.assertEquals(0, v1)
self.assertEquals(10, v2)
self.assertEquals(10, v3)
def test_minimal_size_constraint():
solver = Solver()
v1 = Variable(0)
v2 = Variable(10)
v3 = Variable(10)
c1 = EqualsConstraint(a=v2, b=v3)
c2 = LessThanConstraint(smaller=v1, bigger=v3, delta=10)
solver.add_constraint(c1)
solver.add_constraint(c2)
# Check everything is ok on start
solver.solve()
assert 0 == v1
assert 10 == v2
assert 10 == v3
# Change v1 to 2, after solve it should be 0 again due to LT constraint
v1.value = 2
solver.solve()
assert 0 == v1
assert 10 == v2
assert 10 == v3
# Change v3 to 20, after solve v2 will follow thanks to EQ constraint
v3.value = 20
solver.solve()
assert 0 == v1
assert 20 == v2
assert 20 == v3
# Change v3 to 0, after solve it should be 10 due to LT.delta = 10, v2
# should also be 10 due to EQ constraint
v3.value = 0
solver.solve()
assert 0 == v1
assert 10 == v2
assert 10 == v3
