def save(self, subj, node=None):
""" Save an object to a database node.
:param subj: the object to save
:param node: the database node to save to (if omitted, will re-save to
same node as previous save)
"""
if node is not None:
subj.__node__ = node
# naively copy properties from object to node
props = {}
for key, value in subj.__dict__.items():
if not key.startswith("_"):
props[key] = value
if hasattr(subj, "__node__"):
subj.__node__.set_properties(props)
self.graph.cypher.run("START a=node({a}) MATCH (a)-[r]->(b) DELETE r",
{"a": subj.__node__})
else:
subj.__node__, = self.graph.create(props)
# write rels
if hasattr(subj, "__rel__"):
batch = WriteBatch(self.graph)
for rel_type, rels in subj.__rel__.items():
for rel_props, endpoint in rels:
end_node = self._get_node(endpoint)
if end_node not in self.graph:
raise ValueError(end_node)
batch.create((subj.__node__, rel_type, end_node, rel_props))
batch.run()
return subj
def save(self, subj, node=None):
""" Save an object to a database node.
:param subj: the object to save
:param node: the database node to save to (if omitted, will re-save to
same node as previous save)
"""
if node is not None:
subj.__node__ = node
# naively copy properties from object to node
props = {}
for key, value in subj.__dict__.items():
if not key.startswith("_"):
props[key] = value
if hasattr(subj, "__node__"):
subj.__node__.set_properties(props)
self.graph.cypher.run(
"START a=node({a}) MATCH (a)-[r]->(b) DELETE r",
{"a": subj.__node__})
else:
subj.__node__, = self.graph.create(props)
# write rels
if hasattr(subj, "__rel__"):
batch = WriteBatch(self.graph)
for rel_type, rels in subj.__rel__.items():
for rel_props, endpoint in rels:
end_node = self._get_node(endpoint)
if end_node not in self.graph:
raise ValueError(end_node)
batch.create(
(subj.__node__, rel_type, end_node, rel_props))
batch.run()
return subj
class TestNodeCreation(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
self.graph = graph
def test_can_create_single_empty_node(self):
self.batch.create(node())
a, = self.batch.submit()
assert isinstance(a, Node)
assert a.properties == {}
def test_can_create_single_node_with_streaming(self):
self.batch.create(Node(name="Alice"))
for result in self.batch.stream():
assert isinstance(result, Node)
assert result.properties == {"name": "Alice"}
def test_can_create_multiple_nodes(self):
self.batch.create({"name": "Alice"})
self.batch.create(node({"name": "Bob"}))
self.batch.create(node(name="Carol"))
alice, bob, carol = self.batch.submit()
assert isinstance(alice, Node)
assert isinstance(bob, Node)
assert isinstance(carol, Node)
assert alice["name"] == "Alice"
assert bob["name"] == "Bob"
assert carol["name"] == "Carol"
def test_can_handle_json_response_with_no_content(graph):
# This example might fail if the server bug is fixed that returns
# a 200 response with application/json content-type and no content.
batch = WriteBatch(graph)
batch.create((0, "KNOWS", 1))
results = batch.submit()
assert results == []
def test_can_handle_json_response_with_no_content(graph):
# This example might fail if the server bug is fixed that returns
# a 200 response with application/json content-type and no content.
batch = WriteBatch(graph)
batch.create((0, "KNOWS", 1))
results = batch.submit()
assert results == []
class TestNodeCreation(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
self.graph = graph
def test_can_create_single_empty_node(self):
self.batch.create(node())
a, = self.batch.submit()
assert isinstance(a, Node)
assert a.properties == {}
def test_can_create_single_node_with_streaming(self):
self.batch.create(Node(name="Alice"))
for result in self.batch.stream():
assert isinstance(result, Node)
assert result.properties == {"name": "Alice"}
def test_can_create_multiple_nodes(self):
self.batch.create({"name": "Alice"})
self.batch.create(node({"name": "Bob"}))
self.batch.create(node(name="Carol"))
alice, bob, carol = self.batch.submit()
assert isinstance(alice, Node)
assert isinstance(bob, Node)
assert isinstance(carol, Node)
assert alice["name"] == "Alice"
assert bob["name"] == "Bob"
assert carol["name"] == "Carol"
def test_can_use_return_values_as_references(graph):
batch = WriteBatch(graph)
a = batch.create(node(name="Alice"))
b = batch.create(node(name="Bob"))
batch.create(rel(a, "KNOWS", b))
results = batch.submit()
ab = results[2]
assert isinstance(ab, Relationship)
assert ab.start_node["name"] == "Alice"
assert ab.end_node["name"] == "Bob"
def test_can_use_return_values_as_references(graph):
batch = WriteBatch(graph)
a = batch.create(node(name="Alice"))
b = batch.create(node(name="Bob"))
batch.create(rel(a, "KNOWS", b))
results = batch.submit()
ab = results[2]
assert isinstance(ab, Relationship)
assert ab.start_node["name"] == "Alice"
assert ab.end_node["name"] == "Bob"
class TestDeletion(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
self.graph = graph
def test_can_delete_relationship_and_related_nodes(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
self.batch.create((0, "KNOWS", 1))
alice, bob, ab = self.batch.submit()
assert alice.exists
assert bob.exists
assert ab.exists
self.batch.clear()
self.batch.delete(ab)
self.batch.delete(alice)
self.batch.delete(bob)
self.batch.run()
assert not alice.exists
assert not bob.exists
assert not ab.exists
class TestDeletion(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
self.graph = graph
def test_can_delete_relationship_and_related_nodes(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
self.batch.create((0, "KNOWS", 1))
alice, bob, ab = self.batch.submit()
assert alice.exists
assert bob.exists
assert ab.exists
self.batch.clear()
self.batch.delete(ab)
self.batch.delete(alice)
self.batch.delete(bob)
self.batch.run()
assert not alice.exists
assert not bob.exists
assert not ab.exists
class TestUniqueRelationshipCreation(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
def test_can_create_relationship_if_none_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
alice, bob = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(
alice, ("KNOWS", {"since": 2000}), bob)
path, = self.batch.submit()
knows = path.relationships[0]
assert isinstance(knows, Relationship)
assert knows.start_node == alice
assert knows.type == "KNOWS"
assert knows.end_node == bob
assert knows["since"] == 2000
self.recycling = [knows, alice, bob]
def test_will_get_relationship_if_one_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
alice, bob = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(
alice, ("KNOWS", {"since": 2000}), bob)
self.batch.get_or_create_path(
alice, ("KNOWS", {"since": 2000}), bob)
path1, path2 = self.batch.submit()
assert path1 == path2
def test_will_fail_batch_if_more_than_one_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
self.batch.create((0, "KNOWS", 1))
self.batch.create((0, "KNOWS", 1))
alice, bob, k1, k2 = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, "KNOWS", bob)
try:
self.batch.submit()
except BatchError as error:
cause = error.__cause__
assert isinstance(cause, GraphError)
assert cause.__class__.__name__ == "UniquePathNotUniqueException"
else:
assert False
def test_can_create_relationship_and_start_node(self):
self.batch.create({"name": "Bob"})
bob, = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(None, "KNOWS", bob)
path, = self.batch.submit()
knows = path.relationships[0]
alice = knows.start_node
assert isinstance(knows, Relationship)
assert isinstance(alice, Node)
assert knows.type == "KNOWS"
assert knows.end_node == bob
self.recycling = [knows, alice, bob]
def test_can_create_relationship_and_end_node(self):
self.batch.create({"name": "Alice"})
alice, = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, "KNOWS", None)
path, = self.batch.submit()
knows = path.relationships[0]
bob = knows.end_node
assert isinstance(knows, Relationship)
assert knows.start_node == alice
assert knows.type == "KNOWS"
assert isinstance(bob, Node)
self.recycling = [knows, alice, bob]
class TestUniqueRelationshipCreation(object):
@pytest.fixture(autouse=True)
def setup(self, graph):
self.batch = WriteBatch(graph)
def test_can_create_relationship_if_none_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
alice, bob = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, ("KNOWS", {"since": 2000}), bob)
path, = self.batch.submit()
knows = path.relationships[0]
assert isinstance(knows, Relationship)
assert knows.start_node == alice
assert knows.type == "KNOWS"
assert knows.end_node == bob
assert knows["since"] == 2000
self.recycling = [knows, alice, bob]
def test_will_get_relationship_if_one_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
alice, bob = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, ("KNOWS", {"since": 2000}), bob)
self.batch.get_or_create_path(alice, ("KNOWS", {"since": 2000}), bob)
path1, path2 = self.batch.submit()
assert path1 == path2
def test_will_fail_batch_if_more_than_one_exists(self):
self.batch.create({"name": "Alice"})
self.batch.create({"name": "Bob"})
self.batch.create((0, "KNOWS", 1))
self.batch.create((0, "KNOWS", 1))
alice, bob, k1, k2 = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, "KNOWS", bob)
try:
self.batch.submit()
except BatchError as error:
cause = error.__cause__
assert cause.__class__.__name__ == "UniquePathNotUniqueException"
else:
assert False
def test_can_create_relationship_and_start_node(self):
self.batch.create({"name": "Bob"})
bob, = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(None, "KNOWS", bob)
path, = self.batch.submit()
knows = path.relationships[0]
alice = knows.start_node
assert isinstance(knows, Relationship)
assert isinstance(alice, Node)
assert knows.type == "KNOWS"
assert knows.end_node == bob
self.recycling = [knows, alice, bob]
def test_can_create_relationship_and_end_node(self):
self.batch.create({"name": "Alice"})
alice, = self.batch.submit()
self.batch.clear()
self.batch.get_or_create_path(alice, "KNOWS", None)
path, = self.batch.submit()
knows = path.relationships[0]
bob = knows.end_node
assert isinstance(knows, Relationship)
assert knows.start_node == alice
assert knows.type == "KNOWS"
assert isinstance(bob, Node)
self.recycling = [knows, alice, bob]
