| trace = stacktrace() |
| |
| |
| def test_add_edge_ok(): |
| g = new_graph() |
| k1 = g.key('t1', 'id1') |
| k2 = g.key('t1', 'id2') |
| |
| g.add_edge(parent=k1, child=k2) |
| |
| # Nodes aren't "visible" yet. |
| assert.true(g.node(k1) == None) |
| |
| # They are after being added explicitly. |
| g.add_node(k1, {}) |
| assert.true(g.node(k1) != None) |
| |
| test_add_edge_ok() |
| |
| |
| def test_edge_redeclaration(): |
| g = new_graph() |
| k1 = g.key('t1', 'id1') |
| k2 = g.key('t1', 'id2') |
| |
| g.add_edge(parent=k1, child=k2, title='blah') |
| |
| assert.fails( |
| lambda: g.add_edge(parent=k1, child=k2, title='blah'), |
| 'Relation "blah" between .* is redeclared') |
| |
| # Using a different title is fine. |
| g.add_edge(parent=k1, child=k2, title='zzz') |
| |
| test_edge_redeclaration() |
| |
| |
| def test_cycle_detection(): |
| g = new_graph() |
| edge = lambda par, ch: g.add_edge(g.key('t', par), g.key('t', ch)) |
| |
| edge('1', '2') |
| edge('2', '3') |
| edge('1', '3') |
| edge('3', '4') |
| |
| assert.fails(lambda: edge('4', '1'), 'introduces a cycle') |
| |
| test_cycle_detection() |
