Unify tests for digraph and multidigraph (#43)

* Adds support for multigraphs

* Refactors `_is_edge_attr_match`

* Filters relations by __label__ during `_lookup`

* Bundles relation attributes together for lookup

* Refactors and adds inline docs

* Adds tests for multigraph support

* Cleans up inline docs

* Removes slicing list twice to avoid two copies in memory

* Supports WHERE clause for relationships in multigraphs

* Adds test for multigraph with WHERE clause on single edge

* Accounts for WHERE with string node attributes in MultiDiGraphs

* Unifies all unit tests to work with both DiGraphs and MultiDiGraphs

* Completes multidigraph test for WHERE on node attribute

grandcypher/__init__.py

@@ -235,7 +235,7 @@ def _is_edge_attr_match(
             continue
         if host_edges.get(attr) != val:
             return False
-
+    
     return True
 
 
@@ -260,7 +260,6 @@ def _aggregate_edge_labels(edges: Dict) -> Dict:
             aggregated[edge_id] = attrs
     return aggregated
 
-
 def _get_entity_from_host(
     host: Union[nx.DiGraph, nx.MultiDiGraph], entity_name, entity_attribute=None
 ):
@@ -330,6 +329,7 @@ def inner(
             if isinstance(host, nx.MultiDiGraph):
                 # if any of the relations between nodes satisfies condition, return True
                 r_vals = _get_entity_from_host(host, *host_entity_id)
+                r_vals = [r_vals] if not isinstance(r_vals, list) else r_vals
                 val = any(operator(r_val, value) for r_val in r_vals)
             else:
                 val = operator(_get_entity_from_host(host, *host_entity_id), value)
@@ -485,6 +485,7 @@ def _lookup(self, data_paths: List[str], offset_limit) -> Dict[str, List]:
 
             result[data_path] = list(ret)[offset_limit]
 
+
         return result
 
     def return_clause(self, clause):
@@ -726,6 +727,7 @@ def _edge_hop_motifs(self, motif: nx.MultiDiGraph) -> List[Tuple[nx.Graph, dict]
             if motif.out_degree(n) == 0 and motif.in_degree(n) == 0:
                 new_motif.add_node(n, **motif.nodes[n])
         motifs: List[Tuple[nx.DiGraph, dict]] = [(new_motif, {})]
+
         for u, v, k in motif.edges:  # OutMultiEdgeView([('a', 'b', 0)])
             new_motifs = []
             min_hop = motif.edges[u, v, k]["__min_hop__"]