Allow duplicate role players (#85)

## What is the goal of this PR?
Allowing duplicate roles to be played in a relation as of typedb/typedb#5667.

This means now that `relation.getRolePlayerMap()` should return a map from `Role` to `[Thing]` rather than `set(Thing)`

## What are the changes implemented in this PR?
* Update types for `rolePlayerMap` in the concept API

Author: flyingsilverfin

grakn/service/Session/Concept/Concept.py

@@ -595,8 +595,8 @@ def to_pair(tx_service, iter_res):
             else:
                 id_mapping[role_id] = role
                 role_key = role
-                mapping[role_key] = set()
-            mapping[role_key].add(player)
+                mapping[role_key] = []
+            mapping[role_key].append(player)
 
         return mapping
 

tests/integration/test_answer.py

@@ -138,7 +138,7 @@ def test_delete_returns_Void(self):
             tx.close()
         client.keyspaces().delete("matchdelete_void")
 
-    def test_compute_count_empty_graph_anwer_Value(self):
+    def test_compute_count_empty_graph_answer_Value(self):
         with client.session("countingzero") as local_session:
             tx = local_session.transaction().write()
             tx.put_entity_type("foo")
@@ -149,7 +149,7 @@ def test_compute_count_empty_graph_anwer_Value(self):
             tx.close()
         client.keyspaces().delete("countingzero")
 
-    def test_aggr_count_empty_graph_anwer_Value(self):
+    def test_aggr_count_empty_graph_answer_Value(self):
         with client.session("countingnonzero") as local_session:
             tx = local_session.transaction().write()
             tx.query("define person sub entity; dog sub entity;")

tests/integration/test_concept.py

@@ -669,8 +669,8 @@ def test_role_players_2_roles_1_player(self):
         role_players_map = parentship.role_players_map()
         self.assertEqual(len(role_players_map.keys()), 2)
         for role in role_players_map:
-            players_set = role_players_map[role]
-            self.assertEqual(len(players_set), 1)
+            players_list = role_players_map[role]
+            self.assertEqual(len(players_list), 1)
             self.assertTrue(role.is_role())
 
         role_players = list(parentship.role_players())
@@ -691,14 +691,13 @@ def test_role_players_1_role_2_players(self):
         role_players_map = parentship.role_players_map()
         self.assertEqual(len(role_players_map.keys()), 1)
         for role in role_players_map:
-            players_set = role_players_map[role]
-            self.assertEqual(len(players_set), 2)
+            players_list = role_players_map[role]
+            self.assertEqual(len(players_list), 2)
             self.assertTrue(role.is_role())
 
         role_players = list(parentship.role_players())
         self.assertEqual(len(role_players), 2)
 
-    @unittest.skip("behaviour changed on server side")
     def test_role_players_2_roles_same_player(self):
         parentship_type = self.tx.get_schema_concept("parentship")
         person_type = self.tx.get_schema_concept("person")
@@ -714,12 +713,34 @@ def test_role_players_2_roles_same_player(self):
         role_players_map = parentship.role_players_map()
         self.assertEqual(len(role_players_map.keys()), 2)
         for role in role_players_map:
-            players_set = role_players_map[role]
-            self.assertEqual(len(players_set), 1)
+            players_list = role_players_map[role]
+            self.assertEqual(len(players_list), 1)
             self.assertTrue(role.is_role())
 
         role_players = list(parentship.role_players())
-        self.assertEqual(len(role_players), 1)
+        self.assertEqual(len(role_players), 2)
+        self.assertTrue(role_players[0].is_thing())
+
+    def test_role_players_1_role_same_player(self):
+        parentship_type = self.tx.get_schema_concept("parentship")
+        person_type = self.tx.get_schema_concept("person")
+        parent_role = self.tx.get_schema_concept("parent")
+
+        self_parent = person_type.create()
+        parentship = parentship_type.create()
+
+        parentship.assign(parent_role, self_parent)
+        parentship.assign(parent_role, self_parent)
+
+        role_players_map = parentship.role_players_map()
+        self.assertEqual(len(role_players_map.keys()), 1)
+        for role in role_players_map:
+            players_list = role_players_map[role]
+            self.assertEqual(len(players_list), 2)
+            self.assertTrue(role.is_role())
+
+        role_players = list(parentship.role_players())
+        self.assertEqual(len(role_players), 2)
         self.assertTrue(role_players[0].is_thing())
 
     def test_assign_unassign(self):