[lib] Handle a case where viewer is added to a thread while being its…

… member

Summary:
It is possible that we receive an operation about viewer being added to a thread while the thread is already present in the store and viewer is its member. We need to make sure that we don't override the whole thread and instead update it as little as possible.

https://linear.app/comm/issue/ENG-8720/add-protection-against-thick-thread-creation-overwriting-existing

Depends on D13483

Test Plan: Create a sidebar, add, remove, and add a user and check on that user's device if the thread is displayed and updated correctly.

Reviewers: kamil, will, ashoat

Reviewed By: ashoat

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13490

lib/shared/dm-ops/add-members-spec.js

@@ -16,7 +16,9 @@ import { messageTypes } from '../../types/message-types-enum.js';
 import type { RawMessageInfo } from '../../types/message-types.js';
 import type { AddMembersMessageData } from '../../types/messages/add-members.js';
 import { minimallyEncodeMemberInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
+import type { ThickRawThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import { joinThreadSubscription } from '../../types/subscription-types.js';
+import type { ThreadPermissionsInfo } from '../../types/thread-permission-types.js';
 import type { ThickMemberInfo } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import { values } from '../../utils/objects.js';
@@ -41,6 +43,46 @@ function createAddNewMembersMessageDataWithInfoFromDMOperation(
   return { messageData, rawMessageInfo };
 }
 
+function createPermissionsForNewMembers(
+  threadInfo: ThickRawThreadInfo,
+  utilities: ProcessDMOperationUtilities,
+): {
+  +membershipPermissions: ThreadPermissionsInfo,
+  +roleID: string,
+} {
+  const defaultRoleID = values(threadInfo.roles).find(role =>
+    roleIsDefaultRole(role),
+  )?.id;
+  invariant(defaultRoleID, 'Default role ID must exist');
+
+  const { parentThreadID } = threadInfo;
+  const parentThreadInfo = parentThreadID
+    ? utilities.threadInfos[parentThreadID]
+    : null;
+  if (parentThreadID && !parentThreadInfo) {
+    console.log(
+      `Parent thread with ID ${parentThreadID} was expected while adding ` +
+        'thread members but is missing from the store',
+    );
+  }
+  invariant(
+    !parentThreadInfo || parentThreadInfo.thick,
+    'Parent thread should be thick',
+  );
+
+  const { membershipPermissions } = createRoleAndPermissionForThickThreads(
+    threadInfo.type,
+    threadInfo.id,
+    defaultRoleID,
+    parentThreadInfo,
+  );
+
+  return {
+    membershipPermissions,
+    roleID: defaultRoleID,
+  };
+}
+
 const addMembersSpec: DMOperationSpec<DMAddMembersOperation> = Object.freeze({
   notificationsCreationData: async (dmOperation: DMAddMembersOperation) => {
     return {
@@ -69,31 +111,9 @@ const addMembersSpec: DMOperationSpec<DMAddMembersOperation> = Object.freeze({
       };
     }
 
-    const defaultRoleID = values(currentThreadInfo.roles).find(role =>
-      roleIsDefaultRole(role),
-    )?.id;
-    invariant(defaultRoleID, 'Default role ID must exist');
-
-    const parentThreadID = currentThreadInfo.parentThreadID;
-    const parentThreadInfo = parentThreadID
-      ? utilities.threadInfos[parentThreadID]
-      : null;
-    if (parentThreadID && !parentThreadInfo) {
-      console.log(
-        `Parent thread with ID ${parentThreadID} was expected while adding ` +
-          'thread members but is missing from the store',
-      );
-    }
-    invariant(
-      !parentThreadInfo || parentThreadInfo.thick,
-      'Parent thread should be thick',
-    );
-
-    const { membershipPermissions } = createRoleAndPermissionForThickThreads(
-      currentThreadInfo.type,
-      currentThreadInfo.id,
-      defaultRoleID,
-      parentThreadInfo,
+    const { membershipPermissions, roleID } = createPermissionsForNewMembers(
+      currentThreadInfo,
+      utilities,
     );
 
     const memberTimestamps = { ...currentThreadInfo.timestamps.members };
@@ -122,7 +142,7 @@ const addMembersSpec: DMOperationSpec<DMAddMembersOperation> = Object.freeze({
       newMembers.push(
         minimallyEncodeMemberInfo<ThickMemberInfo>({
           id: userID,
-          role: defaultRoleID,
+          role: roleID,
           permissions: membershipPermissions,
           isSender: editorID === viewerID,
           subscription: joinThreadSubscription,
@@ -175,4 +195,5 @@ const addMembersSpec: DMOperationSpec<DMAddMembersOperation> = Object.freeze({
 export {
   addMembersSpec,
   createAddNewMembersMessageDataWithInfoFromDMOperation,
+  createPermissionsForNewMembers,
 };

lib/shared/dm-ops/add-viewer-to-thread-members-spec.js

@@ -2,6 +2,7 @@
 
 import uuid from 'uuid';
 
+import { createPermissionsForNewMembers } from './add-members-spec.js';
 import { createThickRawThreadInfo } from './create-thread-spec.js';
 import type {
   DMOperationSpec,
@@ -15,7 +16,12 @@ import { messageTypes } from '../../types/message-types-enum.js';
 import type { RawMessageInfo } from '../../types/message-types.js';
 import { messageTruncationStatus } from '../../types/message-types.js';
 import type { AddMembersMessageData } from '../../types/messages/add-members.js';
+import {
+  minimallyEncodeMemberInfo,
+  minimallyEncodeThreadCurrentUserInfo,
+} from '../../types/minimally-encoded-thread-permissions-types.js';
 import { joinThreadSubscription } from '../../types/subscription-types.js';
+import type { ThickMemberInfo } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import { rawMessageInfoFromMessageData } from '../message-utils.js';
 import { userIsMember } from '../thread-utils.js';
@@ -56,7 +62,7 @@ const addViewerToThreadMembersSpec: DMOperationSpec<DMAddViewerToThreadMembersOp
       dmOperation: DMAddViewerToThreadMembersOperation,
       utilities: ProcessDMOperationUtilities,
     ) => {
-      const { time, messageID, addedUserIDs, existingThreadDetails } =
+      const { time, messageID, addedUserIDs, existingThreadDetails, editorID } =
         dmOperation;
       const { threadInfos } = utilities;
 
@@ -100,6 +106,54 @@ const addViewerToThreadMembersSpec: DMOperationSpec<DMAddViewerToThreadMembersOp
         }
       }
 
+      if (currentThreadInfo) {
+        const { membershipPermissions, roleID } =
+          createPermissionsForNewMembers(currentThreadInfo, utilities);
+
+        const newMemberInfos = newMembers.map(userID =>
+          minimallyEncodeMemberInfo<ThickMemberInfo>({
+            id: userID,
+            role: roleID,
+            permissions: membershipPermissions,
+            isSender: editorID === utilities.viewerID,
+            subscription: joinThreadSubscription,
+          }),
+        );
+
+        const resultThreadInfo = {
+          ...currentThreadInfo,
+          members: [...currentThreadInfo.members, ...newMemberInfos],
+          currentUser: minimallyEncodeThreadCurrentUserInfo({
+            role: roleID,
+            permissions: membershipPermissions,
+            subscription: joinThreadSubscription,
+            unread: true,
+          }),
+          timestamps: {
+            ...currentThreadInfo.timestamps,
+            members: {
+              ...currentThreadInfo.timestamps.members,
+              ...memberTimestamps,
+            },
+          },
+        };
+
+        const updateInfos = [
+          {
+            type: updateTypes.UPDATE_THREAD,
+            id: uuid.v4(),
+            time,
+            threadInfo: resultThreadInfo,
+          },
+        ];
+
+        return {
+          rawMessageInfos,
+          updateInfos,
+          blobOps: [],
+        };
+      }
+
       const resultThreadInfo = createThickRawThreadInfo(
         {
           ...existingThreadDetails,
@@ -132,7 +186,7 @@ const addViewerToThreadMembersSpec: DMOperationSpec<DMAddViewerToThreadMembersOp
         },
       ];
       return {
-        rawMessageInfos,
+        rawMessageInfos: [],
         updateInfos,
         blobOps: [],
       };