fix: Restore missing membership_lists filter

This can be done be reusing the filterset class with
DjangoFilterConnectionField. It would be worthwhile checking if this
work can be encapsulated in a resuable function, as there is now a lot
of custom code whose function is not obvious.

terraso_backend/apps/collaboration/graphql/memberships.py

@@ -19,13 +19,33 @@
 from graphene import relay
 from graphene_django import DjangoObjectType
 
-from apps.graphql.schema.commons import TerrasoConnection
-
 from ..models import Membership, MembershipList
 
+# from apps.graphql.schema.commons import TerrasoConnection
+
+
 logger = structlog.get_logger(__name__)
 
 
+# TODO: trying to import this from apps.graphql.schema.commons causes a circular import
+# Created an issue to move the module to apps.graphql.commons, as that seems simplest
+# https://github.com/techmatters/terraso-backend/issues/820
+class TerrasoConnection(graphene.Connection):
+    class Meta:
+        abstract = True
+
+    total_count = graphene.Int(required=True)
+
+    def resolve_total_count(self, info, **kwargs):
+        queryset = self.iterable
+        return queryset.count()
+
+    @classmethod
+    def __init_subclass_with_meta__(cls, **options):
+        options["strict_types"] = options.pop("strict_types", True)
+        super().__init_subclass_with_meta__(**options)
+
+
 class MembershipListNodeMixin:
     id = graphene.ID(source="pk", required=True)
     account_membership = graphene.Field("apps.collaboration.graphql.CollaborationMembershipNode")

terraso_backend/apps/graphql/schema/schema.graphql

@@ -561,7 +561,7 @@ type StoryMapNode implements Node {
 
 type ProjectMembershipListNode implements Node {
   membershipType: CollaborationMembershipListMembershipTypeChoices!
-  memberships: ProjectMembershipNode!
+  memberships(offset: Int, before: String, after: String, first: Int, last: Int, user: ID, user_In: [ID], userRole: UserRole, user_Email_Icontains: String, user_Email_In: [String], membershipStatus: CollaborationMembershipMembershipStatusChoices, user_Email_Not: String): ProjectMembershipNodeConnection
   id: ID!
   accountMembership: CollaborationMembershipNode
   membershipsCount: Int
@@ -576,6 +576,24 @@ enum CollaborationMembershipListMembershipTypeChoices {
   CLOSED
 }
 
+type ProjectMembershipNodeConnection {
+  """Pagination data for this connection."""
+  pageInfo: PageInfo!
+
+  """Contains the nodes in this connection."""
+  edges: [ProjectMembershipNodeEdge!]!
+  totalCount: Int!
+}
+
+"""A Relay edge containing a `ProjectMembershipNode` and its cursor."""
+type ProjectMembershipNodeEdge {
+  """The item at the end of the edge"""
+  node: ProjectMembershipNode!
+
+  """A cursor for use in pagination"""
+  cursor: String!
+}
+
 type ProjectMembershipNode implements Node {
   membershipList: ProjectMembershipListNode!
   user: UserNode

terraso_backend/apps/project_management/graphql/projects.py

@@ -22,9 +22,12 @@
 from django_filters import FilterSet
 from graphene import relay
 from graphene_django import DjangoObjectType
-from graphene_django.filter import TypedFilter
+from graphene_django.filter import DjangoFilterConnectionField, TypedFilter
 
 from apps.audit_logs import api as log_api
+from apps.collaboration.graphql.memberships import (
+    CollaborationMembershipFilterSet as MembershipFilterSet,
+)
 from apps.collaboration.graphql.memberships import (
     CollaborationMembershipNode as MembershipNode,
 )
@@ -76,11 +79,13 @@ def resolve_user_role(self, info):
 
 
 class ProjectMembershipListNode(DjangoObjectType, MembershipListNodeMixin):
-    memberships = graphene.Field(ProjectMembershipNode, required=True)
-
     class Meta(MembershipListNodeMixin.Meta):
         pass
 
+    memberships = DjangoFilterConnectionField(
+        ProjectMembershipNode, filterset_class=MembershipFilterSet
+    )
+
 
 class ProjectFilterSet(FilterSet):
     member = TypedFilter(field_name="membership_list__memberships__user")