Fix inaccurate numbers on group details screen

ts/util/getGroupMemberships.ts

@@ -0,0 +1,65 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { GroupV2Membership } from '../components/conversation/conversation-details/ConversationDetailsMembershipList';
+import {
+  GroupV2PendingMembership,
+  GroupV2RequestingMembership,
+} from '../components/conversation/conversation-details/PendingInvites';
+import { ConversationType } from '../state/ducks/conversations';
+import { isConversationUnregistered } from './isConversationUnregistered';
+
+export const getGroupMemberships = (
+  {
+    memberships = [],
+    pendingApprovalMemberships = [],
+    pendingMemberships = [],
+  }: Readonly<
+    Pick<
+      ConversationType,
+      'memberships' | 'pendingApprovalMemberships' | 'pendingMemberships'
+    >
+  >,
+  getConversationById: (conversationId: string) => undefined | ConversationType
+): {
+  memberships: Array<GroupV2Membership>;
+  pendingApprovalMemberships: Array<GroupV2RequestingMembership>;
+  pendingMemberships: Array<GroupV2PendingMembership>;
+} => ({
+  memberships: memberships.reduce(
+    (result: Array<GroupV2Membership>, membership) => {
+      const member = getConversationById(membership.conversationId);
+      if (!member || isConversationUnregistered(member)) {
+        return result;
+      }
+      return [...result, { isAdmin: membership.isAdmin, member }];
+    },
+    []
+  ),
+  pendingApprovalMemberships: pendingApprovalMemberships.reduce(
+    (result: Array<GroupV2RequestingMembership>, membership) => {
+      const member = getConversationById(membership.conversationId);
+      if (!member || isConversationUnregistered(member)) {
+        return result;
+      }
+      return [...result, { member }];
+    },
+    []
+  ),
+  pendingMemberships: pendingMemberships.reduce(
+    (result: Array<GroupV2PendingMembership>, membership) => {
+      const member = getConversationById(membership.conversationId);
+      if (!member || isConversationUnregistered(member)) {
+        return result;
+      }
+      return [
+        ...result,
+        {
+          member,
+          metadata: { addedByUserId: membership.addedByUserId },
+        },
+      ];
+    },
+    []
+  ),
+});