def test_add():
"""
add a node to a Graph
"""
from arbiter.graph import Graph
graph = Graph()
assert_equals(graph.nodes, frozenset())
assert_equals(graph.roots, frozenset())
assert_false('foo' in graph)
graph.add('foo')
assert_equals(graph.nodes, frozenset(('foo',)))
assert_equals(graph.roots, frozenset(('foo',)))
assert_true('foo' in graph)
assert_equals(graph.children('foo'), frozenset())
assert_equals(graph.parents('foo'), frozenset())
assert_false(graph.ancestor_of('foo', 'foo'))
graph.add('bar', ('foo', 'baz'))
assert_equals(graph.nodes, frozenset(('foo', 'bar', 'baz')))
assert_equals(graph.roots, frozenset(('foo',)))
assert_true('foo' in graph)
assert_true('bar' in graph)
assert_true('baz' in graph)
assert_equals(graph.children('foo'), frozenset(('bar',)))
assert_equals(graph.children('bar'), frozenset())
assert_equals(graph.children('baz'), frozenset(('bar',)))
assert_equals(graph.parents('foo'), frozenset())
assert_equals(graph.parents('bar'), frozenset(('foo', 'baz')))
assert_equals(graph.parents('baz'), frozenset())
assert_false(graph.ancestor_of('foo', 'foo'))
assert_false(graph.ancestor_of('foo', 'bar'))
assert_false(graph.ancestor_of('foo', 'baz'))
assert_true(graph.ancestor_of('bar', 'foo'))
assert_false(graph.ancestor_of('bar', 'bar'))
assert_true(graph.ancestor_of('bar', 'baz'))
assert_false(graph.ancestor_of('baz', 'foo'))
assert_false(graph.ancestor_of('baz', 'bar'))
assert_false(graph.ancestor_of('baz', 'baz'))
assert_raises(ValueError, graph.add, 'baz', ('bar',))
assert_raises(ValueError, graph.add, 'ouroboros', ('ouroboros',))
assert_raises(ValueError, graph.add, 'foo')
assert_equals(graph.nodes, frozenset(('foo', 'bar', 'baz')))
assert_equals(graph.roots, frozenset(('foo',)))
def test_naming():
"""
Node names just need to be hashable.
"""
from arbiter.graph import Graph, Strategy
graph = Graph()
for name in (1, float('NaN'), 0, None, '', frozenset(), (), False, sum):
graph.add('child1', frozenset((name,)))
graph.add(name)
assert_true(name in graph)
assert_equals(graph.nodes, frozenset((name, 'child1')))
assert_equals(graph.roots, frozenset((name,)))
assert_equals(graph.children(name), frozenset(('child1',)))
assert_equals(graph.parents(name), frozenset())
assert_false(graph.ancestor_of(name, name))
graph.add('child2', frozenset((name,)))
assert_equals(
graph.children(name),
frozenset(('child1', 'child2'))
)
graph.remove(name)
graph.remove('child1')
graph.remove('child2')
assert_equals(graph.nodes, frozenset())
graph.add(None)
graph.add('', parents=((),))
graph.add((), parents=(frozenset(),))
graph.add(frozenset())
assert_equals(graph.nodes, frozenset((None, '', (), frozenset())))
assert_equals(graph.roots, frozenset((None, frozenset())))
graph.remove((), strategy=Strategy.remove)
assert_equals(graph.nodes, frozenset((None, frozenset())))
assert_equals(graph.roots, frozenset((None, frozenset())))
assert_raises(TypeError, graph.add, [])
assert_raises(TypeError, graph.add, 'valid', parents=([],))