def test_KnowledgeEngine_reset():
"""
Given a set of fixed facts, they're still there
after a reset.
Also, we have in account that InitialFact() is always there.
And that if we add a normal fact after that, it's not persistent
"""
from pyknow.engine import KnowledgeEngine
from pyknow.fact import Fact, L
ke = KnowledgeEngine()
ke.deffacts(Fact(foo=L(1)))
ke.deffacts(Fact(foo=L(1), bar=L(2)))
ke.reset()
assert len(ke.facts.facts) == 3
ke = KnowledgeEngine()
ke.deffacts(Fact(foo=L(1)))
ke.declare(Fact(foo=L(9)))
ke.deffacts(Fact(foo=L(1), bar=L(2)))
ke.reset()
assert len(ke.facts.facts) == 3
ke = KnowledgeEngine()
ke.deffacts(Fact(foo=L(1)))
ke.declare(Fact(foo=L(9)))
ke.reset()
assert len(ke.facts.facts) == 2
