feature(provider): implement comment tombstones for threads

packages/provider/src/TiptapCollabProvider.ts

@@ -8,16 +8,27 @@ import {
 
 import { TiptapCollabProviderWebsocket } from './TiptapCollabProviderWebsocket.js'
 import type {
+  DeleteCommentOptions,
   TCollabComment, TCollabThread, THistoryVersion,
 } from './types.js'
 
+const defaultDeleteCommentOptions: DeleteCommentOptions = {
+  deleteContent: false,
+  deleteThread: false,
+}
+
 export type TiptapCollabProviderConfiguration =
   Required<Pick<HocuspocusProviderConfiguration, 'name'>> &
   Partial<HocuspocusProviderConfiguration> &
   (Required<Pick<AdditionalTiptapCollabProviderConfiguration, 'websocketProvider'>> |
   Required<Pick<AdditionalTiptapCollabProviderConfiguration, 'appId'>>|
   Required<Pick<AdditionalTiptapCollabProviderConfiguration, 'baseUrl'>>) &
-  Pick<AdditionalTiptapCollabProviderConfiguration, 'user'>
+  Pick<AdditionalTiptapCollabProviderConfiguration, 'user'> & {
+    /**
+     * Pass `true` if you want to delete a thread when the first comment is deleted.
+     */
+    deleteThreadOnFirstCommentDelete?: boolean,
+  }
 
 export interface AdditionalTiptapCollabProviderConfiguration {
   /**
@@ -107,14 +118,27 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return this.configuration.document.getMap<number>(`${this.tiptapCollabConfigurationPrefix}config`).set('autoVersioning', 0)
   }
 
+  /**
+   * Returns all users in the document as Y.Map objects
+   * @returns An array of Y.Map objects
+   */
   private getYThreads() {
     return this.configuration.document.getArray<Y.Map<any>>(`${this.tiptapCollabConfigurationPrefix}threads`)
   }
 
+  /**
+   * Finds all threads in the document and returns them as JSON objects
+   * @returns An array of threads as JSON objects
+   */
   getThreads<Data, CommentData>(): TCollabThread<Data, CommentData>[] {
     return this.getYThreads().toJSON() as TCollabThread<Data, CommentData>[]
   }
 
+  /**
+   * Find the index of a thread by its id
+   * @param id The thread id
+   * @returns The index of the thread or null if not found
+   */
   private getThreadIndex(id: string): number | null {
     let index = null
 
@@ -131,6 +155,11 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return index
   }
 
+  /**
+   * Gets a single thread by its id
+   * @param id The thread id
+   * @returns The thread as a JSON object or null if not found
+   */
   getThread<Data, CommentData>(id: string): TCollabThread<Data, CommentData> | null {
     const index = this.getThreadIndex(id)
 
@@ -141,6 +170,11 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return this.getYThreads().get(index).toJSON() as TCollabThread<Data, CommentData>
   }
 
+  /**
+   * Gets a single thread by its id as a Y.Map object
+   * @param id The thread id
+   * @returns The thread as a Y.Map object or null if not found
+   */
   private getYThread(id: string) {
     const index = this.getThreadIndex(id)
 
@@ -151,14 +185,20 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return this.getYThreads().get(index)
   }
 
-  createThread(data: Omit<TCollabThread, 'id' | 'createdAt' | 'updatedAt' | 'comments'>) {
+  /**
+   * Create a new thread
+   * @param data The thread data
+   * @returns The created thread
+   */
+  createThread(data: Omit<TCollabThread, 'id' | 'createdAt' | 'updatedAt' | 'comments' | 'deletedComments'>) {
     let createdThread: TCollabThread = {} as TCollabThread
 
     this.document.transact(() => {
       const thread = new Y.Map()
       thread.set('id', uuidv4())
       thread.set('createdAt', (new Date()).toISOString())
       thread.set('comments', new Y.Array())
+      thread.set('deletedComments', new Y.Array())
 
       this.getYThreads().push([thread])
       createdThread = this.updateThread(String(thread.get('id')), data)
@@ -167,6 +207,12 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return createdThread
   }
 
+  /**
+   * Update a specific thread
+   * @param id The thread id
+   * @param data New data for the thread
+   * @returns The updated thread or null if the thread is not found
+   */
   updateThread(id: TCollabThread['id'], data: Partial<Pick<TCollabThread, 'data'> & {
     resolvedAt: TCollabThread['resolvedAt'] | null
   }>) {
@@ -195,6 +241,11 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return updatedThread
   }
 
+  /**
+   * Delete a specific thread and all its comments
+   * @param id The thread id
+   * @returns void
+   */
   deleteThread(id: TCollabThread['id']) {
     const index = this.getThreadIndex(id)
 
@@ -205,26 +256,52 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     this.getYThreads().delete(index, 1)
   }
 
-  getThreadComments(threadId: TCollabThread['id']): TCollabComment[] | null {
+  /**
+   * Returns comments from a thread, either deleted or not
+   * @param threadId The thread id
+   * @param includeDeleted If you want to include deleted comments, defaults to `false`
+   * @returns The comments or null if the thread is not found
+   */
+  getThreadComments(threadId: TCollabThread['id'], includeDeleted?: boolean): TCollabComment[] | null {
     const index = this.getThreadIndex(threadId)
 
     if (index === null) {
       return null
     }
 
-    return this.getThread(threadId)?.comments ?? []
+    const comments = !includeDeleted ? this.getThread(threadId)?.comments : [...(this.getThread(threadId)?.comments || []), ...(this.getThread(threadId)?.deletedComments || [])].sort((a, b) => {
+      return a.createdAt.localeCompare(b.createdAt)
+    })
+
+    return comments ?? []
   }
 
-  getThreadComment(threadId: TCollabThread['id'], commentId: TCollabComment['id']): TCollabComment | null {
+  /**
+   * Get a single comment from a specific thread
+   * @param threadId The thread id
+   * @param commentId The comment id
+   * @param includeDeleted If you want to include deleted comments in the search
+   * @returns The comment or null if not found
+   */
+  getThreadComment(threadId: TCollabThread['id'], commentId: TCollabComment['id'], includeDeleted?: boolean): TCollabComment | null {
     const index = this.getThreadIndex(threadId)
 
     if (index === null) {
       return null
     }
 
-    return this.getThread(threadId)?.comments.find(comment => comment.id === commentId) ?? null
+    const comments = this.getThreadComments(threadId, includeDeleted)
+
+    return comments?.find(comment => comment.id === commentId) ?? null
   }
 
+  /**
+   * Adds a comment to a thread
+   * @param threadId The thread id
+   * @param data The comment data
+   * @returns The updated thread or null if the thread is not found
+   * @example addComment('123', { content: 'Hello world', data: { author: 'Maria Doe' } })
+   */
   addComment(threadId: TCollabThread['id'], data: Omit<TCollabComment, 'id' | 'updatedAt' | 'createdAt'>) {
     let updatedThread: TCollabThread = {} as TCollabThread
 
@@ -246,6 +323,14 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return updatedThread
   }
 
+  /**
+   * Update a comment in a thread
+   * @param threadId The thread id
+   * @param commentId The comment id
+   * @param data The new comment data
+   * @returns The updated thread or null if the thread or comment is not found
+   * @example updateComment('123', { content: 'The new content', data: { attachments: ['file1.jpg'] }})
+   */
   updateComment(threadId: TCollabThread['id'], commentId: TCollabComment['id'], data: Partial<Pick<TCollabComment, 'data' | 'content'>>) {
     let updatedThread: TCollabThread = {} as TCollabThread
 
@@ -281,7 +366,16 @@ export class TiptapCollabProvider extends HocuspocusProvider {
     return updatedThread
   }
 
-  deleteComment(threadId: TCollabThread['id'], commentId: TCollabComment['id']) {
+  /**
+   * Deletes a comment from a thread
+   * @param threadId The thread id
+   * @param commentId The comment id
+   * @param options A set of options that control how the comment is deleted
+   * @returns The updated thread or null if the thread or comment is not found
+   */
+  deleteComment(threadId: TCollabThread['id'], commentId: TCollabComment['id'], options: DeleteCommentOptions) {
+    const { deleteContent, deleteThread } = { ...defaultDeleteCommentOptions, ...options }
+
     const thread = this.getYThread(threadId)
 
     if (thread === null) return null
@@ -297,22 +391,39 @@ export class TiptapCollabProvider extends HocuspocusProvider {
 
     // if the first comment of a thread is deleted we also
     // delete the thread itself as the source comment is gone
-    if (commentIndex === 0) {
+    if (commentIndex === 0 && (deleteThread || (this.configuration as TiptapCollabProviderConfiguration).deleteThreadOnFirstCommentDelete)) {
       this.deleteThread(threadId)
       return
     }
 
-    if (commentIndex > 0) {
-      thread.get('comments').delete(commentIndex)
-    }
+    const comment = thread.get('comments').get(commentIndex)
+    const newComment = new Y.Map()
+
+    newComment.set('id', comment.get('id'))
+    newComment.set('createdAt', comment.get('createdAt'))
+    newComment.set('updatedAt', (new Date()).toISOString())
+    newComment.set('deletedAt', (new Date()).toISOString())
+    newComment.set('data', comment.get('data'))
+    newComment.set('content', deleteContent ? null : comment.get('content'))
+
+    thread.get('deletedComments').push([newComment])
+    thread.get('comments').delete(commentIndex)
 
     return thread.toJSON() as TCollabThread
   }
 
+  /**
+   * Start watching threads for changes
+   * @param callback The callback function to be called when a thread changes
+   */
   watchThreads(callback: () => void) {
     this.getYThreads().observeDeep(callback)
   }
 
+  /**
+   * Stop watching threads for changes
+   * @param callback The callback function to be removed
+   */
   unwatchThreads(callback: () => void) {
     this.getYThreads().unobserveDeep(callback)
   }

packages/provider/src/types.ts

@@ -112,13 +112,15 @@ export type TCollabThread<Data = any, CommentData = any> = {
   updatedAt: number;
   resolvedAt?: string; // (new Date()).toISOString()
   comments: TCollabComment<CommentData>[];
+  deletedComments: TCollabComment<CommentData>[];
   data: Data
 }
 
 export type TCollabComment<Data = any> = {
   id: string;
-  createdAt: number;
-  updatedAt: number;
+  createdAt: string;
+  updatedAt: string;
+  deletedAt?: string;
   data: Data
   content: any
 }
@@ -183,3 +185,15 @@ export type THistoryDocumentRevertedEvent = {
   event: 'document.reverted';
   version: number;
 };
+
+export type DeleteCommentOptions = {
+  /**
+   * If `true`, the thread will also be deleted if the deleted comment was the first comment in the thread.
+   */
+  deleteThread?: boolean
+
+  /**
+   * If `true`, will remove the content of the deleted comment
+   */
+  deleteContent?: boolean
+}