diff --git a/src/node/db/API.js b/src/node/db/API.ts
similarity index 90%
rename from src/node/db/API.js
rename to src/node/db/API.ts
index b9efb5411..8b84693ec 100644
--- a/src/node/db/API.js
+++ b/src/node/db/API.ts
@@ -104,7 +104,7 @@ Example returns:
 }
 
 */
-exports.getAttributePool = async (padID) => {
+exports.getAttributePool = async (padID: string) => {
   const pad = await getPadSafe(padID, true);
   return {pool: pad.pool};
 };
@@ -122,7 +122,7 @@ Example returns:
 }
 
 */
-exports.getRevisionChangeset = async (padID, rev) => {
+exports.getRevisionChangeset = async (padID: string, rev: string) => {
   // try to parse the revision number
   if (rev !== undefined) {
     rev = checkValidRev(rev);
@@ -155,7 +155,7 @@ Example returns:
 {code: 0, message:"ok", data: {text:"Welcome Text"}}
 {code: 1, message:"padID does not exist", data: null}
 */
-exports.getText = async (padID, rev) => {
+exports.getText = async (padID: string, rev: string) => {
   // try to parse the revision number
   if (rev !== undefined) {
     rev = checkValidRev(rev);
@@ -173,7 +173,7 @@ exports.getText = async (padID, rev) => {
     }
 
     // get the text of this revision
-    // getInternalRevisionAText() returns an atext object but we only want the .text inside it.
+    // getInternalRevisionAText() returns an atext object, but we only want the .text inside it.
     // Details at https://github.com/ether/etherpad-lite/issues/5073
     const {text} = await pad.getInternalRevisionAText(rev);
     return {text};
@@ -200,7 +200,7 @@ Example returns:
  * @param {String} authorId the id of the author, defaulting to empty string
  * @returns {Promise<void>}
  */
-exports.setText = async (padID, text, authorId = '') => {
+exports.setText = async (padID: string, text?: string, authorId: string = ''): Promise<void> => {
   // text is required
   if (typeof text !== 'string') {
     throw new CustomError('text is not a string', 'apierror');
@@ -225,7 +225,7 @@ Example returns:
  @param {String} text the text of the pad
  @param {String} authorId the id of the author, defaulting to empty string
  */
-exports.appendText = async (padID, text, authorId = '') => {
+exports.appendText = async (padID:string, text?: string, authorId:string = '') => {
   // text is required
   if (typeof text !== 'string') {
     throw new CustomError('text is not a string', 'apierror');
@@ -247,7 +247,7 @@ Example returns:
  @param {String} rev the revision number, defaulting to the latest revision
  @return {Promise<{html: string}>} the html of the pad
 */
-exports.getHTML = async (padID, rev) => {
+exports.getHTML = async (padID: string, rev: string): Promise<{ html: string; }> => {
   if (rev !== undefined) {
     rev = checkValidRev(rev);
   }
@@ -283,7 +283,7 @@ Example returns:
  @param {String} html the html of the pad
  @param {String} authorId the id of the author, defaulting to empty string
 */
-exports.setHTML = async (padID, html, authorId = '') => {
+exports.setHTML = async (padID: string, html:string|object, authorId = '') => {
   // html string is required
   if (typeof html !== 'string') {
     throw new CustomError('html is not a string', 'apierror');
@@ -324,7 +324,7 @@ Example returns:
  @param {Number} start the start point of the chat-history
  @param {Number} end the end point of the chat-history
 */
-exports.getChatHistory = async (padID, start, end) => {
+exports.getChatHistory = async (padID: string, start:number, end:number) => {
   if (start && end) {
     if (start < 0) {
       throw new CustomError('start is below zero', 'apierror');
@@ -374,7 +374,7 @@ Example returns:
  @param {String} authorID the id of the author
  @param {Number} time the timestamp of the chat-message
 */
-exports.appendChatMessage = async (padID, text, authorID, time) => {
+exports.appendChatMessage = async (padID: string, text: string|object, authorID: string, time: number) => {
   // text is required
   if (typeof text !== 'string') {
     throw new CustomError('text is not a string', 'apierror');
@@ -404,7 +404,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
  @param {String} padID the id of the pad
 */
-exports.getRevisionsCount = async (padID) => {
+exports.getRevisionsCount = async (padID: string) => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   return {revisions: pad.getHeadRevisionNumber()};
@@ -419,7 +419,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
  @param {String} padID the id of the pad
 */
-exports.getSavedRevisionsCount = async (padID) => {
+exports.getSavedRevisionsCount = async (padID: string) => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   return {savedRevisions: pad.getSavedRevisionsNumber()};
@@ -434,7 +434,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
  @param {String} padID the id of the pad
 */
-exports.listSavedRevisions = async (padID) => {
+exports.listSavedRevisions = async (padID: string) => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   return {savedRevisions: pad.getSavedRevisionsList()};
@@ -450,7 +450,7 @@ Example returns:
     @param {String} padID the id of the pad
      @param {Number} rev the revision number, defaulting to the latest revision
 */
-exports.saveRevision = async (padID, rev) => {
+exports.saveRevision = async (padID: string, rev: number) => {
   // check if rev is a number
   if (rev !== undefined) {
     rev = checkValidRev(rev);
@@ -483,7 +483,7 @@ Example returns:
     @param {String} padID the id of the pad
  @return {Promise<{lastEdited: number}>} the timestamp of the last revision of the pad
 */
-exports.getLastEdited = async (padID) => {
+exports.getLastEdited = async (padID: string): Promise<{ lastEdited: number; }> => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   const lastEdited = await pad.getLastEdit();
@@ -497,11 +497,11 @@ Example returns:
 
 {code: 0, message:"ok", data: null}
 {code: 1, message:"pad does already exist", data: null}
- @param {String} padName the name of the new pad
+ @param {String} padID the name of the new pad
     @param {String} text the initial text of the pad
      @param {String} authorId the id of the author, defaulting to empty string
 */
-exports.createPad = async (padID, text, authorId = '') => {
+exports.createPad = async (padID: string, text: string, authorId = '') => {
   if (padID) {
     // ensure there is no $ in the padID
     if (padID.indexOf('$') !== -1) {
@@ -527,7 +527,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
  @param {String} padID the id of the pad
 */
-exports.deletePad = async (padID) => {
+exports.deletePad = async (padID: string) => {
   const pad = await getPadSafe(padID, true);
   await pad.remove();
 };
@@ -543,7 +543,7 @@ exports.deletePad = async (padID) => {
  @param {Number} rev the revision number, defaulting to the latest revision
  @param {String} authorId the id of the author, defaulting to empty string
  */
-exports.restoreRevision = async (padID, rev, authorId = '') => {
+exports.restoreRevision = async (padID: string, rev: number, authorId = '') => {
   // check if rev is a number
   if (rev === undefined) {
     throw new CustomError('rev is not defined', 'apierror');
@@ -563,7 +563,7 @@ exports.restoreRevision = async (padID, rev, authorId = '') => {
   const oldText = pad.text();
   atext.text += '\n';
 
-  const eachAttribRun = (attribs, func) => {
+  const eachAttribRun = (attribs: string[], func:Function) => {
     let textIndex = 0;
     const newTextStart = 0;
     const newTextEnd = atext.text.length;
@@ -580,7 +580,7 @@ exports.restoreRevision = async (padID, rev, authorId = '') => {
   const builder = Changeset.builder(oldText.length);
 
   // assemble each line into the builder
-  eachAttribRun(atext.attribs, (start, end, attribs) => {
+  eachAttribRun(atext.attribs, (start: number, end: number, attribs:string[]) => {
     builder.insert(atext.text.substring(start, end), attribs);
   });
 
@@ -610,7 +610,7 @@ Example returns:
  @param {String} destinationID the id of the destination pad
  @param {Boolean} force whether to overwrite the destination pad if it exists
 */
-exports.copyPad = async (sourceID, destinationID, force) => {
+exports.copyPad = async (sourceID: string, destinationID: string, force: boolean) => {
   const pad = await getPadSafe(sourceID, true);
   await pad.copy(destinationID, force);
 };
@@ -628,7 +628,7 @@ Example returns:
  @param {Boolean} force whether to overwrite the destination pad if it exists
  @param {String} authorId the id of the author, defaulting to empty string
 */
-exports.copyPadWithoutHistory = async (sourceID, destinationID, force, authorId = '') => {
+exports.copyPadWithoutHistory = async (sourceID: string, destinationID: string, force:boolean, authorId = '') => {
   const pad = await getPadSafe(sourceID, true);
   await pad.copyPadWithoutHistory(destinationID, force, authorId);
 };
@@ -645,7 +645,7 @@ Example returns:
  @param {String} destinationID the id of the destination pad
  @param {Boolean} force whether to overwrite the destination pad if it exists
 */
-exports.movePad = async (sourceID, destinationID, force) => {
+exports.movePad = async (sourceID: string, destinationID: string, force:boolean) => {
   const pad = await getPadSafe(sourceID, true);
   await pad.copy(destinationID, force);
   await pad.remove();
@@ -660,7 +660,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
  @param {String} padID the id of the pad
 */
-exports.getReadOnlyID = async (padID) => {
+exports.getReadOnlyID = async (padID: string) => {
   // we don't need the pad object, but this function does all the security stuff for us
   await getPadSafe(padID, true);
 
@@ -679,7 +679,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
     @param {String} roID the readonly id of the pad
 */
-exports.getPadID = async (roID) => {
+exports.getPadID = async (roID: string) => {
   // get the PadId
   const padID = await readOnlyManager.getPadId(roID);
   if (padID == null) {
@@ -699,7 +699,7 @@ Example returns:
     @param {String} padID the id of the pad
      @param {Boolean} publicStatus the public status of the pad
 */
-exports.setPublicStatus = async (padID, publicStatus) => {
+exports.setPublicStatus = async (padID: string, publicStatus: boolean|string) => {
   // ensure this is a group pad
   checkGroupPad(padID, 'publicStatus');
 
@@ -723,7 +723,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
      @param {String} padID the id of the pad
 */
-exports.getPublicStatus = async (padID) => {
+exports.getPublicStatus = async (padID: string) => {
   // ensure this is a group pad
   checkGroupPad(padID, 'publicStatus');
 
@@ -741,7 +741,7 @@ Example returns:
 {code: 1, message:"padID does not exist", data: null}
      @param {String} padID the id of the pad
 */
-exports.listAuthorsOfPad = async (padID) => {
+exports.listAuthorsOfPad = async (padID: string) => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   const authorIDs = pad.getAllAuthors();
@@ -773,7 +773,7 @@ Example returns:
      @param {String} msg the message to send
 */
 
-exports.sendClientsMessage = async (padID, msg) => {
+exports.sendClientsMessage = async (padID: string, msg: string) => {
   await getPadSafe(padID, true); // Throw if the padID is invalid or if the pad does not exist.
   padMessageHandler.handleCustomMessage(padID, msg);
 };
@@ -799,7 +799,7 @@ Example returns:
      @param {String} padID the id of the pad
      @return {Promise<{chatHead: number}>} the chatHead of the pad
 */
-exports.getChatHead = async (padID) => {
+exports.getChatHead = async (padID:string): Promise<{ chatHead: number; }> => {
   // get the pad
   const pad = await getPadSafe(padID, true);
   return {chatHead: pad.chatHead};
@@ -825,7 +825,7 @@ Example returns:
  @param {Number} startRev the start revision number
  @param {Number} endRev the end revision number
 */
-exports.createDiffHTML = async (padID, startRev, endRev) => {
+exports.createDiffHTML = async (padID: string, startRev: number, endRev: number) => {
   // check if startRev is a number
   if (startRev !== undefined) {
     startRev = checkValidRev(startRev);
@@ -846,7 +846,7 @@ exports.createDiffHTML = async (padID, startRev, endRev) => {
   let padDiff;
   try {
     padDiff = new PadDiff(pad, startRev, endRev);
-  } catch (e) {
+  } catch (e:any) {
     throw {stop: e.message};
   }
 
@@ -872,6 +872,7 @@ exports.getStats = async () => {
   const sessionInfos = padMessageHandler.sessioninfos;
 
   const sessionKeys = Object.keys(sessionInfos);
+  // @ts-ignore
   const activePads = new Set(Object.entries(sessionInfos).map((k) => k[1].padId));
 
   const {padIDs} = await padManager.listAllPads();
@@ -888,7 +889,7 @@ exports.getStats = async () => {
  **************************** */
 
 // gets a pad safe
-const getPadSafe = async (padID, shouldExist, text, authorId = '') => {
+const getPadSafe = async (padID: string|object, shouldExist: boolean, text?:string, authorId:string = '') => {
   // check if padID is a string
   if (typeof padID !== 'string') {
     throw new CustomError('padID is not a string', 'apierror');
@@ -917,7 +918,7 @@ const getPadSafe = async (padID, shouldExist, text, authorId = '') => {
 };
 
 // checks if a padID is part of a group
-const checkGroupPad = (padID, field) => {
+const checkGroupPad = (padID: string, field: string) => {
   // ensure this is a group pad
   if (padID && padID.indexOf('$') === -1) {
     throw new CustomError(
diff --git a/src/node/db/AuthorManager.js b/src/node/db/AuthorManager.ts
similarity index 86%
rename from src/node/db/AuthorManager.js
rename to src/node/db/AuthorManager.ts
index 7413b5806..2f4e7d751 100644
--- a/src/node/db/AuthorManager.js
+++ b/src/node/db/AuthorManager.ts
@@ -95,7 +95,7 @@ exports.getColorPalette = () => [
  * Checks if the author exists
  * @param {String} authorID The id of the author
  */
-exports.doesAuthorExist = async (authorID) => {
+exports.doesAuthorExist = async (authorID: string) => {
   const author = await db.get(`globalAuthor:${authorID}`);
 
   return author != null;
@@ -114,7 +114,7 @@ exports.doesAuthorExists = exports.doesAuthorExist;
  * @param {String} mapperkey The database key name for this mapper
  * @param {String} mapper The mapper
  */
-const mapAuthorWithDBKey = async (mapperkey, mapper) => {
+const mapAuthorWithDBKey = async (mapperkey: string, mapper:string) => {
   // try to map to an author
   const author = await db.get(`${mapperkey}:${mapper}`);
 
@@ -142,7 +142,7 @@ const mapAuthorWithDBKey = async (mapperkey, mapper) => {
  * @param {String} token The token of the author
  * @return {Promise<string|*|{authorID: string}|{authorID: *}>}
  */
-const getAuthor4Token = async (token) => {
+const getAuthor4Token = async (token: string) => {
   const author = await mapAuthorWithDBKey('token2author', token);
 
   // return only the sub value authorID
@@ -155,7 +155,7 @@ const getAuthor4Token = async (token) => {
  * @param {Object} user
  * @return {Promise<*>}
  */
-exports.getAuthorId = async (token, user) => {
+exports.getAuthorId = async (token: string, user: object) => {
   const context = {dbKey: token, token, user};
   let [authorId] = await hooks.aCallFirst('getAuthorId', context);
   if (!authorId) authorId = await getAuthor4Token(context.dbKey);
@@ -168,7 +168,7 @@ exports.getAuthorId = async (token, user) => {
  * @deprecated Use `getAuthorId` instead.
  * @param {String} token The token
  */
-exports.getAuthor4Token = async (token) => {
+exports.getAuthor4Token = async (token: string) => {
   warnDeprecated(
       'AuthorManager.getAuthor4Token() is deprecated; use AuthorManager.getAuthorId() instead');
   return await getAuthor4Token(token);
@@ -179,7 +179,7 @@ exports.getAuthor4Token = async (token) => {
  * @param {String} authorMapper The mapper
  * @param {String} name The name of the author (optional)
  */
-exports.createAuthorIfNotExistsFor = async (authorMapper, name) => {
+exports.createAuthorIfNotExistsFor = async (authorMapper: string, name: string) => {
   const author = await mapAuthorWithDBKey('mapper2author', authorMapper);
 
   if (name) {
@@ -195,7 +195,7 @@ exports.createAuthorIfNotExistsFor = async (authorMapper, name) => {
  * Internal function that creates the database entry for an author
  * @param {String} name The name of the author
  */
-exports.createAuthor = async (name) => {
+exports.createAuthor = async (name: string) => {
   // create the new author name
   const author = `a.${randomString(16)}`;
 
@@ -216,41 +216,41 @@ exports.createAuthor = async (name) => {
  * Returns the Author Obj of the author
  * @param {String} author The id of the author
  */
-exports.getAuthor = async (author) => await db.get(`globalAuthor:${author}`);
+exports.getAuthor = async (author: string) => await db.get(`globalAuthor:${author}`);
 
 /**
  * Returns the color Id of the author
  * @param {String} author The id of the author
  */
-exports.getAuthorColorId = async (author) => await db.getSub(`globalAuthor:${author}`, ['colorId']);
+exports.getAuthorColorId = async (author: string) => await db.getSub(`globalAuthor:${author}`, ['colorId']);
 
 /**
  * Sets the color Id of the author
  * @param {String} author The id of the author
  * @param {String} colorId The color id of the author
  */
-exports.setAuthorColorId = async (author, colorId) => await db.setSub(
+exports.setAuthorColorId = async (author: string, colorId: string) => await db.setSub(
     `globalAuthor:${author}`, ['colorId'], colorId);
 
 /**
  * Returns the name of the author
  * @param {String} author The id of the author
  */
-exports.getAuthorName = async (author) => await db.getSub(`globalAuthor:${author}`, ['name']);
+exports.getAuthorName = async (author: string) => await db.getSub(`globalAuthor:${author}`, ['name']);
 
 /**
  * Sets the name of the author
  * @param {String} author The id of the author
  * @param {String} name The name of the author
  */
-exports.setAuthorName = async (author, name) => await db.setSub(
+exports.setAuthorName = async (author: string, name: string) => await db.setSub(
     `globalAuthor:${author}`, ['name'], name);
 
 /**
  * Returns an array of all pads this author contributed to
  * @param {String} authorID The id of the author
  */
-exports.listPadsOfAuthor = async (authorID) => {
+exports.listPadsOfAuthor = async (authorID: string) => {
   /* There are two other places where this array is manipulated:
    * (1) When the author is added to a pad, the author object is also updated
    * (2) When a pad is deleted, each author of that pad is also updated
@@ -275,7 +275,7 @@ exports.listPadsOfAuthor = async (authorID) => {
  * @param {String} authorID The id of the author
  * @param {String} padID The id of the pad the author contributes to
  */
-exports.addPad = async (authorID, padID) => {
+exports.addPad = async (authorID: string, padID: string) => {
   // get the entry
   const author = await db.get(`globalAuthor:${authorID}`);
 
@@ -302,7 +302,7 @@ exports.addPad = async (authorID, padID) => {
  * @param {String} authorID The id of the author
  * @param {String} padID The id of the pad the author contributes to
  */
-exports.removePad = async (authorID, padID) => {
+exports.removePad = async (authorID: string, padID: string) => {
   const author = await db.get(`globalAuthor:${authorID}`);
 
   if (author == null) return;
diff --git a/src/node/db/GroupManager.js b/src/node/db/GroupManager.ts
similarity index 93%
rename from src/node/db/GroupManager.js
rename to src/node/db/GroupManager.ts
index 2ab20ac16..0524c4eda 100644
--- a/src/node/db/GroupManager.js
+++ b/src/node/db/GroupManager.ts
@@ -42,7 +42,7 @@ exports.listAllGroups = async () => {
  * @param {String} groupID The id of the group
  * @return {Promise<void>} Resolves when the group is deleted
  */
-exports.deleteGroup = async (groupID) => {
+exports.deleteGroup = async (groupID: string): Promise<void> => {
   const group = await db.get(`group:${groupID}`);
 
   // ensure group exists
@@ -82,7 +82,7 @@ exports.deleteGroup = async (groupID) => {
  * @param {String} groupID the id of the group to delete
  * @return {Promise<boolean>} Resolves to true if the group exists
  */
-exports.doesGroupExist = async (groupID) => {
+exports.doesGroupExist = async (groupID: string) => {
   // try to get the group entry
   const group = await db.get(`group:${groupID}`);
 
@@ -108,7 +108,7 @@ exports.createGroup = async () => {
  * @param groupMapper the mapper of the group
  * @return {Promise<{groupID: string}|{groupID: *}>} a promise that resolves to the group ID
  */
-exports.createGroupIfNotExistsFor = async (groupMapper) => {
+exports.createGroupIfNotExistsFor = async (groupMapper: string|object) => {
   if (typeof groupMapper !== 'string') {
     throw new CustomError('groupMapper is not a string', 'apierror');
   }
@@ -134,7 +134,7 @@ exports.createGroupIfNotExistsFor = async (groupMapper) => {
  * @param {String} authorId The id of the author
  * @return {Promise<{padID: string}>} a promise that resolves to the id of the new pad
  */
-exports.createGroupPad = async (groupID, padName, text, authorId = '') => {
+exports.createGroupPad = async (groupID: string, padName: string, text: string, authorId: string = ''): Promise<{ padID: string; }> => {
   // create the padID
   const padID = `${groupID}$${padName}`;
 
@@ -167,7 +167,7 @@ exports.createGroupPad = async (groupID, padName, text, authorId = '') => {
  * @param {String} groupID The id of the group
  * @return {Promise<{padIDs: string[]}>} a promise that resolves to the ids of all pads of the group
  */
-exports.listPads = async (groupID) => {
+exports.listPads = async (groupID: string): Promise<{ padIDs: string[]; }> => {
   const exists = await exports.doesGroupExist(groupID);
 
   // ensure the group exists
diff --git a/src/node/db/Pad.js b/src/node/db/Pad.ts
similarity index 89%
rename from src/node/db/Pad.js
rename to src/node/db/Pad.ts
index 884b420f0..fa4af994d 100644
--- a/src/node/db/Pad.js
+++ b/src/node/db/Pad.ts
@@ -1,4 +1,8 @@
 'use strict';
+import {Database} from "ueberdb2";
+import {AChangeSet, APool, AText} from "../types/PadType";
+import {MapArrayType} from "../types/MapType";
+
 /**
  * The pad object, defined with joose
  */
@@ -28,20 +32,29 @@ const promises = require('../utils/promises');
  * @param {String} txt The text to clean
  * @returns {String} The cleaned text
  */
-exports.cleanText = (txt) => txt.replace(/\r\n/g, '\n')
+exports.cleanText = (txt:string): string => txt.replace(/\r\n/g, '\n')
     .replace(/\r/g, '\n')
     .replace(/\t/g, '        ')
     .replace(/\xa0/g, ' ');
 
 class Pad {
+  private db: Database;
+  private atext: AText;
+  private pool: APool;
+  private head: number;
+    private chatHead: number;
+    private publicStatus: boolean;
+    private id: string;
+    private savedRevisions: any[];
   /**
+   * @param id
    * @param [database] - Database object to access this pad's records (and only this pad's records;
    *     the shared global Etherpad database object is still used for all other pad accesses, such
    *     as copying the pad). Defaults to the shared global Etherpad database object. This parameter
    *     can be used to shard pad storage across multiple database backends, to put each pad in its
    *     own database table, or to validate imported pad data before it is written to the database.
    */
-  constructor(id, database = db) {
+  constructor(id:string, database = db) {
     this.db = database;
     this.atext = Changeset.makeAText('\n');
     this.pool = new AttributePool();
@@ -80,7 +93,7 @@ class Pad {
    * @param {String} authorId The id of the author
    * @return {Promise<number|string>}
    */
-  async appendRevision(aChangeset, authorId = '') {
+  async appendRevision(aChangeset:AChangeSet, authorId = '') {
     const newAText = Changeset.applyToAText(aChangeset, this.atext, this.pool);
     if (newAText.text === this.atext.text && newAText.attribs === this.atext.attribs &&
         this.head !== -1) {
@@ -95,6 +108,7 @@ class Pad {
 
     const hook = this.head === 0 ? 'padCreate' : 'padUpdate';
     await Promise.all([
+      // @ts-ignore
       this.db.set(`pad:${this.id}:revs:${newRev}`, {
         changeset: aChangeset,
         meta: {
@@ -129,32 +143,39 @@ class Pad {
   }
 
   toJSON() {
-    const o = {...this, pool: this.pool.toJsonable()};
+    const o:Pad = {...this, pool: this.pool.toJsonable()};
+    // @ts-ignore
     delete o.db;
+    // @ts-ignore
     delete o.id;
     return o;
   }
 
   // save all attributes to the database
   async saveToDatabase() {
+    // @ts-ignore
     await this.db.set(`pad:${this.id}`, this);
   }
 
   // get time of last edit (changeset application)
   async getLastEdit() {
     const revNum = this.getHeadRevisionNumber();
+    // @ts-ignore
     return await this.db.getSub(`pad:${this.id}:revs:${revNum}`, ['meta', 'timestamp']);
   }
 
-  async getRevisionChangeset(revNum) {
+  async getRevisionChangeset(revNum: number) {
+    // @ts-ignore
     return await this.db.getSub(`pad:${this.id}:revs:${revNum}`, ['changeset']);
   }
 
-  async getRevisionAuthor(revNum) {
+  async getRevisionAuthor(revNum: number) {
+    // @ts-ignore
     return await this.db.getSub(`pad:${this.id}:revs:${revNum}`, ['meta', 'author']);
   }
 
-  async getRevisionDate(revNum) {
+  async getRevisionDate(revNum: number) {
+    // @ts-ignore
     return await this.db.getSub(`pad:${this.id}:revs:${revNum}`, ['meta', 'timestamp']);
   }
 
@@ -162,7 +183,8 @@ class Pad {
    * @param {number} revNum - Must be a key revision number (see `getKeyRevisionNumber`).
    * @returns The attribute text stored at `revNum`.
    */
-  async _getKeyRevisionAText(revNum) {
+  async _getKeyRevisionAText(revNum: number) {
+    // @ts-ignore
     return await this.db.getSub(`pad:${this.id}:revs:${revNum}`, ['meta', 'atext']);
   }
 
@@ -182,7 +204,7 @@ class Pad {
     return authorIds;
   }
 
-  async getInternalRevisionAText(targetRev) {
+  async getInternalRevisionAText(targetRev: number) {
     const keyRev = this.getKeyRevisionNumber(targetRev);
     const headRev = this.getHeadRevisionNumber();
     if (targetRev > headRev) targetRev = headRev;
@@ -197,17 +219,17 @@ class Pad {
     return atext;
   }
 
-  async getRevision(revNum) {
+  async getRevision(revNum: number) {
     return await this.db.get(`pad:${this.id}:revs:${revNum}`);
   }
 
   async getAllAuthorColors() {
     const authorIds = this.getAllAuthors();
-    const returnTable = {};
+    const returnTable:MapArrayType<string> = {};
     const colorPalette = authorManager.getColorPalette();
 
     await Promise.all(
-        authorIds.map((authorId) => authorManager.getAuthorColorId(authorId).then((colorId) => {
+        authorIds.map((authorId) => authorManager.getAuthorColorId(authorId).then((colorId:string) => {
           // colorId might be a hex color or an number out of the palette
           returnTable[authorId] = colorPalette[colorId] || colorId;
         })));
@@ -215,7 +237,7 @@ class Pad {
     return returnTable;
   }
 
-  getValidRevisionRange(startRev, endRev) {
+  getValidRevisionRange(startRev: any, endRev:any) {
     startRev = parseInt(startRev, 10);
     const head = this.getHeadRevisionNumber();
     endRev = endRev ? parseInt(endRev, 10) : head;
@@ -236,14 +258,14 @@ class Pad {
     return null;
   }
 
-  getKeyRevisionNumber(revNum) {
+  getKeyRevisionNumber(revNum: number) {
     return Math.floor(revNum / 100) * 100;
   }
 
   /**
    * @returns {string} The pad's text.
    */
-  text() {
+  text(): string {
     return this.atext.text;
   }
 
@@ -258,7 +280,7 @@ class Pad {
    * @param {string} ins - New text to insert at `start` (after the `ndel` characters are deleted).
    * @param {string} [authorId] - Author ID of the user making the change (if applicable).
    */
-  async spliceText(start, ndel, ins, authorId = '') {
+  async spliceText(start:number, ndel:number, ins: string, authorId: string = '') {
     if (start < 0) throw new RangeError(`start index must be non-negative (is ${start})`);
     if (ndel < 0) throw new RangeError(`characters to delete must be non-negative (is ${ndel})`);
     const orig = this.text();
@@ -283,7 +305,7 @@ class Pad {
    * @param {string} [authorId] - The author ID of the user that initiated the change, if
    *     applicable.
    */
-  async setText(newText, authorId = '') {
+  async setText(newText: string, authorId = '') {
     await this.spliceText(0, this.text().length, newText, authorId);
   }
 
@@ -294,7 +316,7 @@ class Pad {
    * @param {string} [authorId] - The author ID of the user that initiated the change, if
    *     applicable.
    */
-  async appendText(newText, authorId = '') {
+  async appendText(newText:string, authorId = '') {
     await this.spliceText(this.text().length - 1, 0, newText, authorId);
   }
 
@@ -308,7 +330,7 @@ class Pad {
    * @param {?number} [time] - Message timestamp (milliseconds since epoch). Deprecated; use
    *     `msgOrText.time` instead.
    */
-  async appendChatMessage(msgOrText, authorId = null, time = null) {
+  async appendChatMessage(msgOrText: string|typeof ChatMessage, authorId = null, time = null) {
     const msg =
           msgOrText instanceof ChatMessage ? msgOrText : new ChatMessage(msgOrText, authorId, time);
     this.chatHead++;
@@ -325,7 +347,7 @@ class Pad {
    * @param {number} entryNum - ID of the desired chat message.
    * @returns {?ChatMessage}
    */
-  async getChatMessage(entryNum) {
+  async getChatMessage(entryNum: number) {
     const entry = await this.db.get(`pad:${this.id}:chat:${entryNum}`);
     if (entry == null) return null;
     const message = ChatMessage.fromObject(entry);
@@ -340,7 +362,7 @@ class Pad {
    *     (inclusive), in order. Note: `start` and `end` form a closed interval, not a half-open
    *     interval as is typical in code.
    */
-  async getChatMessages(start, end) {
+  async getChatMessages(start: string, end: number) {
     const entries =
         await Promise.all(Stream.range(start, end + 1).map(this.getChatMessage.bind(this)));
 
@@ -356,7 +378,7 @@ class Pad {
     });
   }
 
-  async init(text, authorId = '') {
+  async init(text:string, authorId = '') {
     // try to load the pad
     const value = await this.db.get(`pad:${this.id}`);
 
@@ -377,7 +399,7 @@ class Pad {
     await hooks.aCallAll('padLoad', {pad: this});
   }
 
-  async copy(destinationID, force) {
+  async copy(destinationID: string, force: boolean) {
     // Kick everyone from this pad.
     // This was commented due to https://github.com/ether/etherpad-lite/issues/3183.
     // Do we really need to kick everyone out?
@@ -392,15 +414,18 @@ class Pad {
     // if force is true and already exists a Pad with the same id, remove that Pad
     await this.removePadIfForceIsTrueAndAlreadyExist(destinationID, force);
 
-    const copyRecord = async (keySuffix) => {
+    const copyRecord = async (keySuffix: string) => {
       const val = await this.db.get(`pad:${this.id}${keySuffix}`);
       await db.set(`pad:${destinationID}${keySuffix}`, val);
     };
 
     const promises = (function* () {
       yield copyRecord('');
+      // @ts-ignore
       yield* Stream.range(0, this.head + 1).map((i) => copyRecord(`:revs:${i}`));
+      // @ts-ignore
       yield* Stream.range(0, this.chatHead + 1).map((i) => copyRecord(`:chat:${i}`));
+      // @ts-ignore
       yield this.copyAuthorInfoToDestinationPad(destinationID);
       if (destGroupID) yield db.setSub(`group:${destGroupID}`, ['pads', destinationID], 1);
     }).call(this);
@@ -427,8 +452,8 @@ class Pad {
     return {padID: destinationID};
   }
 
-  async checkIfGroupExistAndReturnIt(destinationID) {
-    let destGroupID = false;
+  async checkIfGroupExistAndReturnIt(destinationID: string) {
+    let destGroupID:false|string = false;
 
     if (destinationID.indexOf('$') >= 0) {
       destGroupID = destinationID.split('$')[0];
@@ -442,7 +467,7 @@ class Pad {
     return destGroupID;
   }
 
-  async removePadIfForceIsTrueAndAlreadyExist(destinationID, force) {
+  async removePadIfForceIsTrueAndAlreadyExist(destinationID: string, force: boolean|string) {
     // if the pad exists, we should abort, unless forced.
     const exists = await padManager.doesPadExist(destinationID);
 
@@ -465,13 +490,13 @@ class Pad {
     }
   }
 
-  async copyAuthorInfoToDestinationPad(destinationID) {
+  async copyAuthorInfoToDestinationPad(destinationID: string) {
     // add the new sourcePad to all authors who contributed to the old one
     await Promise.all(this.getAllAuthors().map(
         (authorID) => authorManager.addPad(authorID, destinationID)));
   }
 
-  async copyPadWithoutHistory(destinationID, force, authorId = '') {
+  async copyPadWithoutHistory(destinationID: string, force: string|boolean, authorId = '') {
     // flush the source pad
     this.saveToDatabase();
 
@@ -554,18 +579,18 @@ class Pad {
     }
 
     // remove the readonly entries
-    p.push(readOnlyManager.getReadOnlyId(padID).then(async (readonlyID) => {
+    p.push(readOnlyManager.getReadOnlyId(padID).then(async (readonlyID: string) => {
       await db.remove(`readonly2pad:${readonlyID}`);
     }));
     p.push(db.remove(`pad2readonly:${padID}`));
 
     // delete all chat messages
-    p.push(promises.timesLimit(this.chatHead + 1, 500, async (i) => {
+    p.push(promises.timesLimit(this.chatHead + 1, 500, async (i: string) => {
       await this.db.remove(`pad:${this.id}:chat:${i}`, null);
     }));
 
     // delete all revisions
-    p.push(promises.timesLimit(this.head + 1, 500, async (i) => {
+    p.push(promises.timesLimit(this.head + 1, 500, async (i: string) => {
       await this.db.remove(`pad:${this.id}:revs:${i}`, null);
     }));
 
@@ -587,12 +612,12 @@ class Pad {
   }
 
   // set in db
-  async setPublicStatus(publicStatus) {
+  async setPublicStatus(publicStatus: boolean) {
     this.publicStatus = publicStatus;
     await this.saveToDatabase();
   }
 
-  async addSavedRevision(revNum, savedById, label) {
+  async addSavedRevision(revNum: string, savedById: string, label: string) {
     // if this revision is already saved, return silently
     for (const i in this.savedRevisions) {
       if (this.savedRevisions[i] && this.savedRevisions[i].revNum === revNum) {
@@ -601,7 +626,7 @@ class Pad {
     }
 
     // build the saved revision object
-    const savedRevision = {};
+    const savedRevision:MapArrayType<any> = {};
     savedRevision.revNum = revNum;
     savedRevision.savedById = savedById;
     savedRevision.label = label || `Revision ${revNum}`;
@@ -664,7 +689,7 @@ class Pad {
       if (k === 'author' && v) authorIds.add(v);
     });
     const revs = Stream.range(0, head + 1)
-        .map(async (r) => {
+        .map(async (r: number) => {
           const isKeyRev = r === this.getKeyRevisionNumber(r);
           try {
             return await Promise.all([
@@ -675,7 +700,7 @@ class Pad {
               isKeyRev,
               isKeyRev ? this._getKeyRevisionAText(r) : null,
             ]);
-          } catch (err) {
+          } catch (err:any) {
             err.message = `(pad ${this.id} revision ${r}) ${err.message}`;
             throw err;
           }
@@ -708,7 +733,7 @@ class Pad {
         }
         atext = Changeset.applyToAText(changeset, atext, pool);
         if (isKeyRev) assert.deepEqual(keyAText, atext);
-      } catch (err) {
+      } catch (err:any) {
         err.message = `(pad ${this.id} revision ${r}) ${err.message}`;
         throw err;
       }
@@ -721,12 +746,12 @@ class Pad {
     assert(Number.isInteger(this.chatHead));
     assert(this.chatHead >= -1);
     const chats = Stream.range(0, this.chatHead + 1)
-        .map(async (c) => {
+        .map(async (c: number) => {
           try {
             const msg = await this.getChatMessage(c);
             assert(msg != null);
             assert(msg instanceof ChatMessage);
-          } catch (err) {
+          } catch (err:any) {
             err.message = `(pad ${this.id} chat message ${c}) ${err.message}`;
             throw err;
           }
diff --git a/src/node/db/PadManager.js b/src/node/db/PadManager.ts
similarity index 86%
rename from src/node/db/PadManager.js
rename to src/node/db/PadManager.ts
index 7c4021541..4a447f850 100644
--- a/src/node/db/PadManager.js
+++ b/src/node/db/PadManager.ts
@@ -19,6 +19,8 @@
  * limitations under the License.
  */
 
+import {MapArrayType} from "../types/MapType";
+
 const CustomError = require('../utils/customError');
 const Pad = require('../db/Pad');
 const db = require('./DB');
@@ -35,12 +37,16 @@ const settings = require('../utils/Settings');
  * If this is needed in other places, it would be wise to make this a prototype
  * that's defined somewhere more sensible.
  */
-const globalPads = {
-  get(name) { return this[`:${name}`]; },
-  set(name, value) {
+const globalPads:MapArrayType<any> = {
+  get(name: string)
+  {
+    return this[`:${name}`];
+    },
+  set(name: string, value: any)
+  {
     this[`:${name}`] = value;
   },
-  remove(name) {
+  remove(name: string) {
     delete this[`:${name}`];
   },
 };
@@ -51,6 +57,9 @@ const globalPads = {
  * Updated without db access as new pads are created/old ones removed.
  */
 const padList = new class {
+  private _cachedList: string[] | null;
+    private _list: Set<string>;
+    private _loaded: Promise<void> | null;
   constructor() {
     this._cachedList = null;
     this._list = new Set();
@@ -74,13 +83,13 @@ const padList = new class {
     return this._cachedList;
   }
 
-  addPad(name) {
+  addPad(name: string) {
     if (this._list.has(name)) return;
     this._list.add(name);
     this._cachedList = null;
   }
 
-  removePad(name) {
+  removePad(name: string) {
     if (!this._list.has(name)) return;
     this._list.delete(name);
     this._cachedList = null;
@@ -96,7 +105,7 @@ const padList = new class {
  * @param {string} [authorId] - Optional author ID of the user that initiated the pad creation (if
  *     applicable).
  */
-exports.getPad = async (id, text, authorId = '') => {
+exports.getPad = async (id: string, text: string, authorId:string = '') => {
   // check if this is a valid padId
   if (!exports.isValidPadId(id)) {
     throw new CustomError(`${id} is not a valid padId`, 'apierror');
@@ -140,7 +149,7 @@ exports.listAllPads = async () => {
 };
 
 // checks if a pad exists
-exports.doesPadExist = async (padId) => {
+exports.doesPadExist = async (padId: string) => {
   const value = await db.get(`pad:${padId}`);
 
   return (value != null && value.atext);
@@ -159,7 +168,7 @@ const padIdTransforms = [
 ];
 
 // returns a sanitized padId, respecting legacy pad id formats
-exports.sanitizePadId = async (padId) => {
+exports.sanitizePadId = async (padId: string) => {
   for (let i = 0, n = padIdTransforms.length; i < n; ++i) {
     const exists = await exports.doesPadExist(padId);
 
@@ -169,6 +178,7 @@ exports.sanitizePadId = async (padId) => {
 
     const [from, to] = padIdTransforms[i];
 
+    // @ts-ignore
     padId = padId.replace(from, to);
   }
 
@@ -178,12 +188,12 @@ exports.sanitizePadId = async (padId) => {
   return padId;
 };
 
-exports.isValidPadId = (padId) => /^(g.[a-zA-Z0-9]{16}\$)?[^$]{1,50}$/.test(padId);
+exports.isValidPadId = (padId: string) => /^(g.[a-zA-Z0-9]{16}\$)?[^$]{1,50}$/.test(padId);
 
 /**
  * Removes the pad from database and unloads it.
  */
-exports.removePad = async (padId) => {
+exports.removePad = async (padId: string) => {
   const p = db.remove(`pad:${padId}`);
   exports.unloadPad(padId);
   padList.removePad(padId);
@@ -191,6 +201,6 @@ exports.removePad = async (padId) => {
 };
 
 // removes a pad from the cache
-exports.unloadPad = (padId) => {
+exports.unloadPad = (padId: string) => {
   globalPads.remove(padId);
 };
diff --git a/src/node/db/ReadOnlyManager.js b/src/node/db/ReadOnlyManager.ts
similarity index 89%
rename from src/node/db/ReadOnlyManager.js
rename to src/node/db/ReadOnlyManager.ts
index b96dd3413..23639d665 100644
--- a/src/node/db/ReadOnlyManager.js
+++ b/src/node/db/ReadOnlyManager.ts
@@ -29,14 +29,14 @@ const randomString = require('../utils/randomstring');
  * @param {String} id the pad's id
  * @return {Boolean} true if the id is readonly
  */
-exports.isReadOnlyId = (id) => id.startsWith('r.');
+exports.isReadOnlyId = (id:string) => id.startsWith('r.');
 
 /**
  * returns a read only id for a pad
  * @param {String} padId the id of the pad
  * @return {String} the read only id
  */
-exports.getReadOnlyId = async (padId) => {
+exports.getReadOnlyId = async (padId:string) => {
   // check if there is a pad2readonly entry
   let readOnlyId = await db.get(`pad2readonly:${padId}`);
 
@@ -57,14 +57,14 @@ exports.getReadOnlyId = async (padId) => {
  * @param {String} readOnlyId read only id
  * @return {String} the padId
  */
-exports.getPadId = async (readOnlyId) => await db.get(`readonly2pad:${readOnlyId}`);
+exports.getPadId = async (readOnlyId:string) => await db.get(`readonly2pad:${readOnlyId}`);
 
 /**
  * returns the padId and readonlyPadId in an object for any id
  * @param {String} id read only id or real pad id
  * @return {Object} an object with the padId and readonlyPadId
  */
-exports.getIds = async (id) => {
+exports.getIds = async (id:string) => {
   const readonly = exports.isReadOnlyId(id);
 
   // Might be null, if this is an unknown read-only id
diff --git a/src/node/db/SecurityManager.js b/src/node/db/SecurityManager.ts
similarity index 96%
rename from src/node/db/SecurityManager.js
rename to src/node/db/SecurityManager.ts
index 0e5b2c77c..326bf3659 100644
--- a/src/node/db/SecurityManager.js
+++ b/src/node/db/SecurityManager.ts
@@ -19,6 +19,8 @@
  * limitations under the License.
  */
 
+import {UserSettingsObject} from "../types/UserSettingsObject";
+
 const authorManager = require('./AuthorManager');
 const hooks = require('../../static/js/pluginfw/hooks.js');
 const padManager = require('./PadManager');
@@ -55,7 +57,7 @@ const DENY = Object.freeze({accessStatus: 'deny'});
  * @param {Object} userSettings
  * @return {DENY|{accessStatus: String, authorID: String}}
  */
-exports.checkAccess = async (padID, sessionCookie, token, userSettings) => {
+exports.checkAccess = async (padID:string, sessionCookie:string, token:string, userSettings:UserSettingsObject) => {
   if (!padID) {
     authLogger.debug('access denied: missing padID');
     return DENY;
@@ -95,7 +97,7 @@ exports.checkAccess = async (padID, sessionCookie, token, userSettings) => {
   }
 
   // allow plugins to deny access
-  const isFalse = (x) => x === false;
+  const isFalse = (x:boolean) => x === false;
   if (hooks.callAll('onAccessCheck', {padID, token, sessionCookie}).some(isFalse)) {
     authLogger.debug('access denied: an onAccessCheck hook function returned false');
     return DENY;
diff --git a/src/node/db/SessionManager.js b/src/node/db/SessionManager.ts
similarity index 91%
rename from src/node/db/SessionManager.js
rename to src/node/db/SessionManager.ts
index 3d39ed747..c0e43a659 100644
--- a/src/node/db/SessionManager.js
+++ b/src/node/db/SessionManager.ts
@@ -36,7 +36,7 @@ const authorManager = require('./AuthorManager');
  *     sessionCookie, and is bound to a group with the given ID, then this returns the author ID
  *     bound to the session. Otherwise, returns undefined.
  */
-exports.findAuthorID = async (groupID, sessionCookie) => {
+exports.findAuthorID = async (groupID:string, sessionCookie: string) => {
   if (!sessionCookie) return undefined;
   /*
    * Sometimes, RFC 6265-compliant web servers may send back a cookie whose
@@ -65,7 +65,7 @@ exports.findAuthorID = async (groupID, sessionCookie) => {
   const sessionInfoPromises = sessionIDs.map(async (id) => {
     try {
       return await exports.getSessionInfo(id);
-    } catch (err) {
+    } catch (err:any) {
       if (err.message === 'sessionID does not exist') {
         console.debug(`SessionManager getAuthorID: no session exists with ID ${id}`);
       } else {
@@ -75,7 +75,10 @@ exports.findAuthorID = async (groupID, sessionCookie) => {
     return undefined;
   });
   const now = Math.floor(Date.now() / 1000);
-  const isMatch = (si) => (si != null && si.groupID === groupID && now < si.validUntil);
+  const isMatch = (si: {
+    groupID: string;
+    validUntil: number;
+  }|null) => (si != null && si.groupID === groupID && now < si.validUntil);
   const sessionInfo = await promises.firstSatisfies(sessionInfoPromises, isMatch);
   if (sessionInfo == null) return undefined;
   return sessionInfo.authorID;
@@ -86,7 +89,7 @@ exports.findAuthorID = async (groupID, sessionCookie) => {
  * @param {String} sessionID The id of the session
  * @return {Promise<boolean>} Resolves to true if the session exists
  */
-exports.doesSessionExist = async (sessionID) => {
+exports.doesSessionExist = async (sessionID: string) => {
   // check if the database entry of this session exists
   const session = await db.get(`session:${sessionID}`);
   return (session != null);
@@ -99,7 +102,7 @@ exports.doesSessionExist = async (sessionID) => {
  * @param {Number} validUntil The unix timestamp when the session should expire
  * @return {Promise<{sessionID: string}>} the id of the new session
  */
-exports.createSession = async (groupID, authorID, validUntil) => {
+exports.createSession = async (groupID: string, authorID: string, validUntil: number) => {
   // check if the group exists
   const groupExists = await groupManager.doesGroupExist(groupID);
   if (!groupExists) {
@@ -160,7 +163,7 @@ exports.createSession = async (groupID, authorID, validUntil) => {
  * @param {String} sessionID The id of the session
  * @return {Promise<Object>} the sessioninfos
  */
-exports.getSessionInfo = async (sessionID) => {
+exports.getSessionInfo = async (sessionID:string) => {
   // check if the database entry of this session exists
   const session = await db.get(`session:${sessionID}`);
 
@@ -178,7 +181,7 @@ exports.getSessionInfo = async (sessionID) => {
  * @param {String} sessionID The id of the session
  * @return {Promise<void>} Resolves when the session is deleted
  */
-exports.deleteSession = async (sessionID) => {
+exports.deleteSession = async (sessionID:string) => {
   // ensure that the session exists
   const session = await db.get(`session:${sessionID}`);
   if (session == null) {
@@ -207,7 +210,7 @@ exports.deleteSession = async (sessionID) => {
  * @param {String} groupID The id of the group
  * @return {Promise<Object>} The sessioninfos of all sessions of this group
  */
-exports.listSessionsOfGroup = async (groupID) => {
+exports.listSessionsOfGroup = async (groupID: string) => {
   // check that the group exists
   const exists = await groupManager.doesGroupExist(groupID);
   if (!exists) {
@@ -223,7 +226,7 @@ exports.listSessionsOfGroup = async (groupID) => {
  * @param {String} authorID The id of the author
  * @return {Promise<Object>} The sessioninfos of all sessions of this author
  */
-exports.listSessionsOfAuthor = async (authorID) => {
+exports.listSessionsOfAuthor = async (authorID: string) => {
   // check that the author exists
   const exists = await authorManager.doesAuthorExist(authorID);
   if (!exists) {
@@ -240,7 +243,7 @@ exports.listSessionsOfAuthor = async (authorID) => {
  * @param {String} dbkey The db key to use to get the sessions
  * @return {Promise<*>}
  */
-const listSessionsWithDBKey = async (dbkey) => {
+const listSessionsWithDBKey = async (dbkey: string) => {
   // get the group2sessions entry
   const sessionObject = await db.get(dbkey);
   const sessions = sessionObject ? sessionObject.sessionIDs : null;
@@ -249,7 +252,7 @@ const listSessionsWithDBKey = async (dbkey) => {
   for (const sessionID of Object.keys(sessions || {})) {
     try {
       sessions[sessionID] = await exports.getSessionInfo(sessionID);
-    } catch (err) {
+    } catch (err:any) {
       if (err.name === 'apierror') {
         console.warn(`Found bad session ${sessionID} in ${dbkey}`);
         sessions[sessionID] = null;
@@ -262,9 +265,11 @@ const listSessionsWithDBKey = async (dbkey) => {
   return sessions;
 };
 
+
 /**
  * checks if a number is an int
  * @param {number|string} value
  * @return {boolean} If the value is an integer
  */
-const isInt = (value) => (parseFloat(value) === parseInt(value)) && !isNaN(value);
+// @ts-ignore
+const isInt = (value:number|string): boolean => (parseFloat(value) === parseInt(value)) && !isNaN(value);
diff --git a/src/node/eejs/index.js b/src/node/eejs/index.ts
similarity index 90%
rename from src/node/eejs/index.js
rename to src/node/eejs/index.ts
index 31ff2c1a5..eb9e882f0 100644
--- a/src/node/eejs/index.js
+++ b/src/node/eejs/index.ts
@@ -38,16 +38,16 @@ exports.info = {
 
 const getCurrentFile = () => exports.info.file_stack[exports.info.file_stack.length - 1];
 
-exports._init = (b, recursive) => {
+exports._init = (b: any, recursive: boolean) => {
   exports.info.__output_stack.push(exports.info.__output);
   exports.info.__output = b;
 };
 
-exports._exit = (b, recursive) => {
+exports._exit = (b:any, recursive:boolean) => {
   exports.info.__output = exports.info.__output_stack.pop();
 };
 
-exports.begin_block = (name) => {
+exports.begin_block = (name:string) => {
   exports.info.block_stack.push(name);
   exports.info.__output_stack.push(exports.info.__output.get());
   exports.info.__output.set('');
@@ -63,11 +63,17 @@ exports.end_block = () => {
   exports.info.__output.set(exports.info.__output.get().concat(args.content));
 };
 
-exports.require = (name, args, mod) => {
+exports.require = (name:string, args:{
+  e?: Function,
+    require?: Function,
+}, mod:{
+  filename:string,
+    paths:string[],
+}) => {
   if (args == null) args = {};
 
   let basedir = __dirname;
-  let paths = [];
+  let paths:string[] = [];
 
   if (exports.info.file_stack.length) {
     basedir = path.dirname(getCurrentFile().path);
diff --git a/src/node/hooks/express/specialpages.js b/src/node/hooks/express/specialpages.ts
similarity index 82%
rename from src/node/hooks/express/specialpages.js
rename to src/node/hooks/express/specialpages.ts
index 18a17988a..85a23479f 100644
--- a/src/node/hooks/express/specialpages.js
+++ b/src/node/hooks/express/specialpages.ts
@@ -10,10 +10,10 @@ const settings = require('../../utils/Settings');
 const util = require('util');
 const webaccess = require('./webaccess');
 
-exports.expressPreSession = async (hookName, {app}) => {
+exports.expressPreSession = async (hookName:string, {app}:any) => {
   // This endpoint is intended to conform to:
   // https://www.ietf.org/archive/id/draft-inadarei-api-health-check-06.html
-  app.get('/health', (req, res) => {
+  app.get('/health', (req:any, res:any) => {
     res.set('Content-Type', 'application/health+json');
     res.json({
       status: 'pass',
@@ -21,18 +21,18 @@ exports.expressPreSession = async (hookName, {app}) => {
     });
   });
 
-  app.get('/stats', (req, res) => {
+  app.get('/stats', (req:any, res:any) => {
     res.json(require('../../stats').toJSON());
   });
 
-  app.get('/javascript', (req, res) => {
+  app.get('/javascript', (req:any, res:any) => {
     res.send(eejs.require('ep_etherpad-lite/templates/javascript.html', {req}));
   });
 
-  app.get('/robots.txt', (req, res) => {
+  app.get('/robots.txt', (req:any, res:any) => {
     let filePath =
         path.join(settings.root, 'src', 'static', 'skins', settings.skinName, 'robots.txt');
-    res.sendFile(filePath, (err) => {
+    res.sendFile(filePath, (err:any) => {
       // there is no custom robots.txt, send the default robots.txt which dissallows all
       if (err) {
         filePath = path.join(settings.root, 'src', 'static', 'robots.txt');
@@ -41,7 +41,7 @@ exports.expressPreSession = async (hookName, {app}) => {
     });
   });
 
-  app.get('/favicon.ico', (req, res, next) => {
+  app.get('/favicon.ico', (req:any, res:any, next:Function) => {
     (async () => {
       /*
         If this is a url we simply redirect to that one.
@@ -73,14 +73,14 @@ exports.expressPreSession = async (hookName, {app}) => {
   });
 };
 
-exports.expressCreateServer = (hookName, args, cb) => {
+exports.expressCreateServer = (hookName:string, args:any, cb:Function) => {
   // serve index.html under /
-  args.app.get('/', (req, res) => {
+  args.app.get('/', (req:any, res:any) => {
     res.send(eejs.require('ep_etherpad-lite/templates/index.html', {req}));
   });
 
   // serve pad.html under /p
-  args.app.get('/p/:pad', (req, res, next) => {
+  args.app.get('/p/:pad', (req:any, res:any, next:Function) => {
     // The below might break for pads being rewritten
     const isReadOnly = !webaccess.userCanModify(req.params.pad, req);
 
@@ -99,7 +99,7 @@ exports.expressCreateServer = (hookName, args, cb) => {
   });
 
   // serve timeslider.html under /p/$padname/timeslider
-  args.app.get('/p/:pad/timeslider', (req, res, next) => {
+  args.app.get('/p/:pad/timeslider', (req:any, res:any, next:Function) => {
     hooks.callAll('padInitToolbar', {
       toolbar,
     });
@@ -112,7 +112,7 @@ exports.expressCreateServer = (hookName, args, cb) => {
 
   // The client occasionally polls this endpoint to get an updated expiration for the express_sid
   // cookie. This handler must be installed after the express-session middleware.
-  args.app.put('/_extendExpressSessionLifetime', (req, res) => {
+  args.app.put('/_extendExpressSessionLifetime', (req:any, res:any) => {
     // express-session automatically calls req.session.touch() so we don't need to do it here.
     res.json({status: 'ok'});
   });
diff --git a/src/node/hooks/express/static.js b/src/node/hooks/express/static.ts
similarity index 80%
rename from src/node/hooks/express/static.js
rename to src/node/hooks/express/static.ts
index 26c18995a..6b0b75593 100644
--- a/src/node/hooks/express/static.js
+++ b/src/node/hooks/express/static.ts
@@ -1,5 +1,8 @@
 'use strict';
 
+import {MapArrayType} from "../../types/MapType";
+import {PartType} from "../../types/PartType";
+
 const fs = require('fs').promises;
 const minify = require('../../utils/Minify');
 const path = require('path');
@@ -10,16 +13,17 @@ const Yajsml = require('etherpad-yajsml');
 
 // Rewrite tar to include modules with no extensions and proper rooted paths.
 const getTar = async () => {
-  const prefixLocalLibraryPath = (path) => {
+  const prefixLocalLibraryPath = (path:string) => {
     if (path.charAt(0) === '$') {
       return path.slice(1);
     } else {
       return `ep_etherpad-lite/static/js/${path}`;
     }
   };
+
   const tarJson = await fs.readFile(path.join(settings.root, 'src/node/utils/tar.json'), 'utf8');
-  const tar = {};
-  for (const [key, relativeFiles] of Object.entries(JSON.parse(tarJson))) {
+  const tar:MapArrayType<string[]> = {};
+  for (const [key, relativeFiles] of Object.entries(JSON.parse(tarJson)) as [string, string[]][]) {
     const files = relativeFiles.map(prefixLocalLibraryPath);
     tar[prefixLocalLibraryPath(key)] = files
         .concat(files.map((p) => p.replace(/\.js$/, '')))
@@ -28,7 +32,7 @@ const getTar = async () => {
   return tar;
 };
 
-exports.expressPreSession = async (hookName, {app}) => {
+exports.expressPreSession = async (hookName:string, {app}:any) => {
   // Cache both minified and static.
   const assetCache = new CachingMiddleware();
   app.all(/\/javascripts\/(.*)/, assetCache.handle.bind(assetCache));
@@ -58,11 +62,13 @@ exports.expressPreSession = async (hookName, {app}) => {
   // serve plugin definitions
   // not very static, but served here so that client can do
   // require("pluginfw/static/js/plugin-definitions.js");
-  app.get('/pluginfw/plugin-definitions.json', (req, res, next) => {
-    const clientParts = plugins.parts.filter((part) => part.client_hooks != null);
-    const clientPlugins = {};
-    for (const name of new Set(clientParts.map((part) => part.plugin))) {
+  app.get('/pluginfw/plugin-definitions.json', (req: any, res:any, next:Function) => {
+    const clientParts = plugins.parts.filter((part: PartType) => part.client_hooks != null);
+    const clientPlugins:MapArrayType<string> = {};
+    for (const name of new Set(clientParts.map((part: PartType) => part.plugin))) {
+      // @ts-ignore
       clientPlugins[name] = {...plugins.plugins[name]};
+      // @ts-ignore
       delete clientPlugins[name].package;
     }
     res.setHeader('Content-Type', 'application/json; charset=utf-8');
diff --git a/src/node/hooks/express/tests.js b/src/node/hooks/express/tests.ts
similarity index 80%
rename from src/node/hooks/express/tests.js
rename to src/node/hooks/express/tests.ts
index 66b47d2af..f8a1417ef 100644
--- a/src/node/hooks/express/tests.js
+++ b/src/node/hooks/express/tests.ts
@@ -1,5 +1,8 @@
 'use strict';
 
+import {Dirent} from "node:fs";
+import {PluginDef} from "../../types/PartType";
+
 const path = require('path');
 const fsp = require('fs').promises;
 const plugins = require('../../../static/js/pluginfw/plugin_defs');
@@ -8,15 +11,15 @@ const settings = require('../../utils/Settings');
 
 // Returns all *.js files under specDir (recursively) as relative paths to specDir, using '/'
 // instead of path.sep to separate pathname components.
-const findSpecs = async (specDir) => {
-  let dirents;
+const findSpecs = async (specDir: string) => {
+  let dirents: Dirent[];
   try {
     dirents = await fsp.readdir(specDir, {withFileTypes: true});
-  } catch (err) {
+  } catch (err:any) {
     if (['ENOENT', 'ENOTDIR'].includes(err.code)) return [];
     throw err;
   }
-  const specs = [];
+  const specs: string[] = [];
   await Promise.all(dirents.map(async (dirent) => {
     if (dirent.isDirectory()) {
       const subdirSpecs = await findSpecs(path.join(specDir, dirent.name));
@@ -29,12 +32,12 @@ const findSpecs = async (specDir) => {
   return specs;
 };
 
-exports.expressPreSession = async (hookName, {app}) => {
-  app.get('/tests/frontend/frontendTestSpecs.json', (req, res, next) => {
+exports.expressPreSession = async (hookName:string, {app}:any) => {
+  app.get('/tests/frontend/frontendTestSpecs.json', (req:any, res:any, next:Function) => {
     (async () => {
-      const modules = [];
+      const modules:string[] = [];
       await Promise.all(Object.entries(plugins.plugins).map(async ([plugin, def]) => {
-        let {package: {path: pluginPath}} = def;
+        let {package: {path: pluginPath}} = def as PluginDef;
         if (!pluginPath.endsWith(path.sep)) pluginPath += path.sep;
         const specDir = `${plugin === 'ep_etherpad-lite' ? '' : 'static/'}tests/frontend/specs`;
         for (const spec of await findSpecs(path.join(pluginPath, specDir))) {
@@ -59,14 +62,14 @@ exports.expressPreSession = async (hookName, {app}) => {
 
   const rootTestFolder = path.join(settings.root, 'src/tests/frontend/');
 
-  app.get('/tests/frontend/index.html', (req, res) => {
+  app.get('/tests/frontend/index.html', (req:any, res:any) => {
     res.redirect(['./', ...req.url.split('?').slice(1)].join('?'));
   });
 
   // The regexp /[\d\D]{0,}/ is equivalent to the regexp /.*/. The Express route path used here
   // uses the more verbose /[\d\D]{0,}/ pattern instead of /.*/ because path-to-regexp v0.1.7 (the
   // version used with Express v4.x) interprets '.' and '*' differently than regexp.
-  app.get('/tests/frontend/:file([\\d\\D]{0,})', (req, res, next) => {
+  app.get('/tests/frontend/:file([\\d\\D]{0,})', (req:any, res:any, next:Function) => {
     (async () => {
       let file = sanitizePathname(req.params.file);
       if (['', '.', './'].includes(file)) file = 'index.html';
@@ -74,7 +77,7 @@ exports.expressPreSession = async (hookName, {app}) => {
     })().catch((err) => next(err || new Error(err)));
   });
 
-  app.get('/tests/frontend', (req, res) => {
+  app.get('/tests/frontend', (req:any, res:any) => {
     res.redirect(['./frontend/', ...req.url.split('?').slice(1)].join('?'));
   });
 };
diff --git a/src/node/types/PadType.ts b/src/node/types/PadType.ts
index eab10d905..66a9d6ab1 100644
--- a/src/node/types/PadType.ts
+++ b/src/node/types/PadType.ts
@@ -1,16 +1,44 @@
+import {MapArrayType} from "./MapType";
+
 export type PadType = {
+    id: string,
     apool: ()=>APool,
     atext: AText,
-    getInternalRevisionAText: (text:string)=>Promise<AText>
+    pool: APool,
+    getInternalRevisionAText: (text:string)=>Promise<AText>,
+    getValidRevisionRange: (fromRev: string, toRev: string)=>PadRange,
+    getRevision: (rev?: string)=>Promise<any>,
+    head: number,
+    getAllAuthorColors: ()=>Promise<MapArrayType<string>>,
 }
 
 
-type APool = {
-    putAttrib: ([],flag: boolean)=>number
+type PadRange = {
+    startRev: string,
+    endRev: string,
+}
+
+
+export type APool = {
+    putAttrib: ([],flag?: boolean)=>number,
+    numToAttrib: MapArrayType<any>,
+    toJsonable: ()=>any,
+    clone: ()=>APool,
+    check: ()=>Promise<void>,
+    eachAttrib: (callback: (key: string, value: any)=>void)=>void,
 }
 
 
 export type AText = {
     text: string,
     attribs: any
-}
\ No newline at end of file
+}
+
+
+export type PadAuthor = {
+
+}
+
+export type AChangeSet = {
+
+}
diff --git a/src/node/types/PartType.ts b/src/node/types/PartType.ts
new file mode 100644
index 000000000..3785b73e8
--- /dev/null
+++ b/src/node/types/PartType.ts
@@ -0,0 +1,10 @@
+export type PartType = {
+    plugin: string,
+    client_hooks:any
+}
+
+export type PluginDef = {
+    package:{
+        path:string
+    }
+}
diff --git a/src/node/types/UserSettingsObject.ts b/src/node/types/UserSettingsObject.ts
new file mode 100644
index 000000000..7cd196866
--- /dev/null
+++ b/src/node/types/UserSettingsObject.ts
@@ -0,0 +1,5 @@
+export type UserSettingsObject = {
+    canCreate: boolean,
+    readOnly: boolean,
+    padAuthorizations: any
+}
diff --git a/src/node/utils/Cli.js b/src/node/utils/Cli.ts
similarity index 100%
rename from src/node/utils/Cli.js
rename to src/node/utils/Cli.ts
diff --git a/src/node/utils/ExportHtml.js b/src/node/utils/ExportHtml.ts
similarity index 92%
rename from src/node/utils/ExportHtml.js
rename to src/node/utils/ExportHtml.ts
index d14f40e6e..3b84c4380 100644
--- a/src/node/utils/ExportHtml.js
+++ b/src/node/utils/ExportHtml.ts
@@ -1,4 +1,7 @@
 'use strict';
+import {AText, PadType} from "../types/PadType";
+import {MapArrayType} from "../types/MapType";
+
 /**
  * Copyright 2009 Google Inc.
  *
@@ -26,7 +29,7 @@ const _analyzeLine = require('./ExportHelper')._analyzeLine;
 const _encodeWhitespace = require('./ExportHelper')._encodeWhitespace;
 const padutils = require('../../static/js/pad_utils').padutils;
 
-const getPadHTML = async (pad, revNum) => {
+const getPadHTML = async (pad: PadType, revNum: string) => {
   let atext = pad.atext;
 
   // fetch revision atext
@@ -38,7 +41,7 @@ const getPadHTML = async (pad, revNum) => {
   return await getHTMLFromAtext(pad, atext);
 };
 
-const getHTMLFromAtext = async (pad, atext, authorColors) => {
+const getHTMLFromAtext = async (pad:PadType, atext: AText, authorColors?: string[]) => {
   const apool = pad.apool();
   const textLines = atext.text.slice(0, -1).split('\n');
   const attribLines = Changeset.splitAttributionLines(atext.attribs, atext.text);
@@ -48,7 +51,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
 
   await Promise.all([
     // prepare tags stored as ['tag', true] to be exported
-    hooks.aCallAll('exportHtmlAdditionalTags', pad).then((newProps) => {
+    hooks.aCallAll('exportHtmlAdditionalTags', pad).then((newProps: string[]) => {
       newProps.forEach((prop) => {
         tags.push(prop);
         props.push(prop);
@@ -56,7 +59,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
     }),
     // prepare tags stored as ['tag', 'value'] to be exported. This will generate HTML with tags
     // like <span data-tag="value">
-    hooks.aCallAll('exportHtmlAdditionalTagsWithData', pad).then((newProps) => {
+    hooks.aCallAll('exportHtmlAdditionalTagsWithData', pad).then((newProps: string[]) => {
       newProps.forEach((prop) => {
         tags.push(`span data-${prop[0]}="${prop[1]}"`);
         props.push(prop);
@@ -68,10 +71,10 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
   // and maps them to an index in props
   // *3:2 -> the attribute *3 means strong
   // *2:5 -> the attribute *2 means s(trikethrough)
-  const anumMap = {};
+  const anumMap:MapArrayType<number> = {};
   let css = '';
 
-  const stripDotFromAuthorID = (id) => id.replace(/\./g, '_');
+  const stripDotFromAuthorID = (id: string) => id.replace(/\./g, '_');
 
   if (authorColors) {
     css += '<style>\n';
@@ -118,7 +121,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
     }
   });
 
-  const getLineHTML = (text, attribs) => {
+  const getLineHTML = (text: string, attribs: string[]) => {
     // Use order of tags (b/i/u) as order of nesting, for simplicity
     // and decent nesting.  For example,
     // <b>Just bold<b> <b><i>Bold and italics</i></b> <i>Just italics</i>
@@ -126,12 +129,13 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
     // <b>Just bold <i>Bold and italics</i></b> <i>Just italics</i>
     const taker = Changeset.stringIterator(text);
     const assem = Changeset.stringAssembler();
-    const openTags = [];
+    const openTags:string[] = [];
 
-    const getSpanClassFor = (i) => {
+    const getSpanClassFor = (i: string) => {
       // return if author colors are disabled
       if (!authorColors) return false;
 
+      // @ts-ignore
       const property = props[i];
 
       // we are not insterested on properties in the form of ['color', 'red'],
@@ -153,12 +157,13 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
 
     // tags added by exportHtmlAdditionalTagsWithData will be exported as <span> with
     // data attributes
-    const isSpanWithData = (i) => {
+    const isSpanWithData = (i: string) => {
+      // @ts-ignore
       const property = props[i];
       return Array.isArray(property);
     };
 
-    const emitOpenTag = (i) => {
+    const emitOpenTag = (i: string) => {
       openTags.unshift(i);
       const spanClass = getSpanClassFor(i);
 
@@ -168,13 +173,14 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
         assem.append('">');
       } else {
         assem.append('<');
+        // @ts-ignore
         assem.append(tags[i]);
         assem.append('>');
       }
     };
 
     // this closes an open tag and removes its reference from openTags
-    const emitCloseTag = (i) => {
+    const emitCloseTag = (i: string) => {
       openTags.shift();
       const spanClass = getSpanClassFor(i);
       const spanWithData = isSpanWithData(i);
@@ -183,6 +189,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
         assem.append('</span>');
       } else {
         assem.append('</');
+        // @ts-ignore
         assem.append(tags[i]);
         assem.append('>');
       }
@@ -192,7 +199,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
 
     let idx = 0;
 
-    const processNextChars = (numChars) => {
+    const processNextChars = (numChars: number) => {
       if (numChars <= 0) {
         return;
       }
@@ -203,12 +210,12 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
       // this iterates over every op string and decides which tags to open or to close
       // based on the attribs used
       for (const o of ops) {
-        const usedAttribs = [];
+        const usedAttribs:string[] = [];
 
         // mark all attribs as used
         for (const a of attributes.decodeAttribString(o.attribs)) {
           if (a in anumMap) {
-            usedAttribs.push(anumMap[a]); // i = 0 => bold, etc.
+            usedAttribs.push(String(anumMap[a])); // i = 0 => bold, etc.
           }
         }
         let outermostTag = -1;
@@ -256,7 +263,9 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
     };
     // end processNextChars
     if (urls) {
-      urls.forEach((urlData) => {
+      urls.forEach((urlData: [number, {
+        length: number,
+      }]) => {
         const startIndex = urlData[0];
         const url = urlData[1];
         const urlLength = url.length;
@@ -288,7 +297,13 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
   // so we want to do something reasonable there.  We also
   // want to deal gracefully with blank lines.
   // => keeps track of the parents level of indentation
-  let openLists = [];
+
+  type openList = {
+    level: number,
+    type: string,
+  }
+
+  let openLists: openList[] = [];
   for (let i = 0; i < textLines.length; i++) {
     let context;
     const line = _analyzeLine(textLines[i], attribLines[i], apool);
@@ -315,7 +330,7 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
       // To create list parent elements
       if ((!prevLine || prevLine.listLevel !== line.listLevel) ||
           (line.listTypeName !== prevLine.listTypeName)) {
-        const exists = _.find(openLists, (item) => (
+        const exists = _.find(openLists, (item:openList) => (
           item.level === line.listLevel && item.type === line.listTypeName));
         if (!exists) {
           let prevLevel = 0;
@@ -456,12 +471,12 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
   return pieces.join('');
 };
 
-exports.getPadHTMLDocument = async (padId, revNum, readOnlyId) => {
+exports.getPadHTMLDocument = async (padId: string, revNum: string, readOnlyId: number) => {
   const pad = await padManager.getPad(padId);
 
   // Include some Styles into the Head for Export
   let stylesForExportCSS = '';
-  const stylesForExport = await hooks.aCallAll('stylesForExport', padId);
+  const stylesForExport: string[] = await hooks.aCallAll('stylesForExport', padId);
   stylesForExport.forEach((css) => {
     stylesForExportCSS += css;
   });
@@ -480,7 +495,7 @@ exports.getPadHTMLDocument = async (padId, revNum, readOnlyId) => {
 };
 
 // copied from ACE
-const _processSpaces = (s) => {
+const _processSpaces = (s: string) => {
   const doesWrap = true;
   if (s.indexOf('<') < 0 && !doesWrap) {
     // short-cut
@@ -489,6 +504,7 @@ const _processSpaces = (s) => {
   const parts = [];
   s.replace(/<[^>]*>?| |[^ <]+/g, (m) => {
     parts.push(m);
+    return m
   });
   if (doesWrap) {
     let endOfLine = true;
diff --git a/src/node/utils/LibreOffice.js b/src/node/utils/LibreOffice.ts
similarity index 89%
rename from src/node/utils/LibreOffice.js
rename to src/node/utils/LibreOffice.ts
index 339209194..e89ebe460 100644
--- a/src/node/utils/LibreOffice.js
+++ b/src/node/utils/LibreOffice.ts
@@ -27,8 +27,14 @@ const settings = require('./Settings');
 
 const logger = log4js.getLogger('LibreOffice');
 
-const doConvertTask = async (task) => {
+const doConvertTask = async (task:{
+  type: string,
+    srcFile: string,
+  fileExtension: string,
+    destFile: string,
+}) => {
   const tmpDir = os.tmpdir();
+  // @ts-ignore
   const p = runCmd([
     settings.soffice,
     '--headless',
@@ -43,8 +49,10 @@ const doConvertTask = async (task) => {
     tmpDir,
   ], {stdio: [
     null,
-    (line) => logger.info(`[${p.child.pid}] stdout: ${line}`),
-    (line) => logger.error(`[${p.child.pid}] stderr: ${line}`),
+      // @ts-ignore
+      (line) => logger.info(`[${p.child.pid}] stdout: ${line}`),
+      // @ts-ignore
+      (line) => logger.error(`[${p.child.pid}] stderr: ${line}`),
   ]});
   logger.info(`[${p.child.pid}] Converting ${task.srcFile} to ${task.type} in ${tmpDir}`);
   // Soffice/libreoffice is buggy and often hangs.
@@ -56,7 +64,7 @@ const doConvertTask = async (task) => {
   }, 120000);
   try {
     await p;
-  } catch (err) {
+  } catch (err:any) {
     logger.error(`[${p.child.pid}] Conversion failed: ${err.stack || err}`);
     throw err;
   } finally {
@@ -81,7 +89,7 @@ const queue = async.queue(doConvertTask, 1);
  * @param  {String}     type        The type to convert into
  * @param  {Function}   callback    Standard callback function
  */
-exports.convertFile = async (srcFile, destFile, type) => {
+exports.convertFile = async (srcFile: string, destFile: string, type:string) => {
   // Used for the moving of the file, not the conversion
   const fileExtension = type;
 
diff --git a/src/node/utils/NodeVersion.js b/src/node/utils/NodeVersion.ts
similarity index 95%
rename from src/node/utils/NodeVersion.js
rename to src/node/utils/NodeVersion.ts
index ca5412f23..8507412d1 100644
--- a/src/node/utils/NodeVersion.js
+++ b/src/node/utils/NodeVersion.ts
@@ -26,7 +26,7 @@ const semver = require('semver');
  *
  * @param  {String}     minNodeVersion   Minimum required Node version
  */
-exports.enforceMinNodeVersion = (minNodeVersion) => {
+exports.enforceMinNodeVersion = (minNodeVersion: string) => {
   const currentNodeVersion = process.version;
 
   // we cannot use template literals, since we still do not know if we are
@@ -49,7 +49,7 @@ exports.enforceMinNodeVersion = (minNodeVersion) => {
  * @param {Function} epRemovalVersion Etherpad version that will remove support for deprecated
  *     Node releases
  */
-exports.checkDeprecationStatus = (lowestNonDeprecatedNodeVersion, epRemovalVersion) => {
+exports.checkDeprecationStatus = (lowestNonDeprecatedNodeVersion: string, epRemovalVersion:Function) => {
   const currentNodeVersion = process.version;
 
   if (semver.lt(currentNodeVersion, lowestNonDeprecatedNodeVersion)) {
diff --git a/src/node/utils/Settings.js b/src/node/utils/Settings.ts
similarity index 97%
rename from src/node/utils/Settings.js
rename to src/node/utils/Settings.ts
index 48955f291..8f1e058ea 100644
--- a/src/node/utils/Settings.js
+++ b/src/node/utils/Settings.ts
@@ -50,13 +50,13 @@ const nonSettings = [
 
 // This is a function to make it easy to create a new instance. It is important to not reuse a
 // config object after passing it to log4js.configure() because that method mutates the object. :(
-const defaultLogConfig = (level) => ({appenders: {console: {type: 'console'}},
+const defaultLogConfig = (level:string) => ({appenders: {console: {type: 'console'}},
   categories: {
     default: {appenders: ['console'], level},
   }});
 const defaultLogLevel = 'INFO';
 
-const initLogging = (logLevel, config) => {
+const initLogging = (config:any) => {
   // log4js.configure() modifies exports.logconfig so check for equality first.
   log4js.configure(config);
   log4js.getLogger('console');
@@ -70,7 +70,7 @@ const initLogging = (logLevel, config) => {
 
 // Initialize logging as early as possible with reasonable defaults. Logging will be re-initialized
 // with the user's chosen log level and logger config after the settings have been loaded.
-initLogging(defaultLogLevel, defaultLogConfig(defaultLogLevel));
+initLogging(defaultLogConfig(defaultLogLevel));
 
 /* Root path of the installation */
 exports.root = absolutePaths.findEtherpadRoot();
@@ -487,7 +487,7 @@ exports.getGitCommit = () => {
       version = ref;
     }
     version = version.substring(0, 7);
-  } catch (e) {
+  } catch (e:any) {
     logger.warn(`Can't get git version for server header\n${e.message}`);
   }
   return version;
@@ -503,7 +503,7 @@ exports.getEpVersion = () => require('../../package.json').version;
  * This code refactors a previous version that copied & pasted the same code for
  * both "settings.json" and "credentials.json".
  */
-const storeSettings = (settingsObj) => {
+const storeSettings = (settingsObj:any) => {
   for (const i of Object.keys(settingsObj || {})) {
     if (nonSettings.includes(i)) {
       logger.warn(`Ignoring setting: '${i}'`);
@@ -542,8 +542,9 @@ const storeSettings = (settingsObj) => {
  * short syntax "${ABIWORD}", and not "${ABIWORD:null}": the latter would result
  * in the literal string "null", instead.
  */
-const coerceValue = (stringValue) => {
+const coerceValue = (stringValue:string) => {
   // cooked from https://stackoverflow.com/questions/175739/built-in-way-in-javascript-to-check-if-a-string-is-a-valid-number
+  // @ts-ignore
   const isNumeric = !isNaN(stringValue) && !isNaN(parseFloat(stringValue) && isFinite(stringValue));
 
   if (isNumeric) {
@@ -597,7 +598,7 @@ const coerceValue = (stringValue) => {
  *
  * see: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#The_replacer_parameter
  */
-const lookupEnvironmentVariables = (obj) => {
+const lookupEnvironmentVariables = (obj: object) => {
   const stringifiedAndReplaced = JSON.stringify(obj, (key, value) => {
     /*
      * the first invocation of replacer() is with an empty key. Just go on, or
@@ -669,7 +670,7 @@ const lookupEnvironmentVariables = (obj) => {
     logger.debug(
         `Configuration key "${key}" will be read from environment variable "${envVarName}"`);
 
-    return coerceValue(envVarValue);
+    return coerceValue(envVarValue!);
   });
 
   const newSettings = JSON.parse(stringifiedAndReplaced);
@@ -685,7 +686,7 @@ const lookupEnvironmentVariables = (obj) => {
  *
  * The isSettings variable only controls the error logging.
  */
-const parseSettings = (settingsFilename, isSettings) => {
+const parseSettings = (settingsFilename:string, isSettings:boolean) => {
   let settingsStr = '';
 
   let settingsType, notFoundMessage, notFoundFunction;
@@ -720,7 +721,7 @@ const parseSettings = (settingsFilename, isSettings) => {
     const replacedSettings = lookupEnvironmentVariables(settings);
 
     return replacedSettings;
-  } catch (e) {
+  } catch (e:any) {
     logger.error(`There was an error processing your ${settingsType} ` +
         `file from ${settingsFilename}: ${e.message}`);
 
@@ -736,7 +737,7 @@ exports.reloadSettings = () => {
 
   // Init logging config
   exports.logconfig = defaultLogConfig(exports.loglevel ? exports.loglevel : defaultLogLevel);
-  initLogging(exports.loglevel, exports.logconfig);
+  initLogging(exports.logconfig);
 
   if (!exports.skinName) {
     logger.warn('No "skinName" parameter found. Please check out settings.json.template and ' +
@@ -780,7 +781,7 @@ exports.reloadSettings = () => {
   if (exports.abiword) {
     // Check abiword actually exists
     if (exports.abiword != null) {
-      fs.exists(exports.abiword, (exists) => {
+      fs.exists(exports.abiword, (exists: boolean) => {
         if (!exists) {
           const abiwordError = 'Abiword does not exist at this path, check your settings file.';
           if (!exports.suppressErrorsInPadText) {
@@ -794,7 +795,7 @@ exports.reloadSettings = () => {
   }
 
   if (exports.soffice) {
-    fs.exists(exports.soffice, (exists) => {
+    fs.exists(exports.soffice, (exists: boolean) => {
       if (!exists) {
         const sofficeError =
             'soffice (libreoffice) does not exist at this path, check your settings file.';
diff --git a/src/node/utils/padDiff.js b/src/node/utils/padDiff.js
deleted file mode 100644
index 4ab276b4b..000000000
--- a/src/node/utils/padDiff.js
+++ /dev/null
@@ -1,447 +0,0 @@
-'use strict';
-
-const AttributeMap = require('../../static/js/AttributeMap');
-const Changeset = require('../../static/js/Changeset');
-const attributes = require('../../static/js/attributes');
-const exportHtml = require('./ExportHtml');
-
-function PadDiff(pad, fromRev, toRev) {
-  // check parameters
-  if (!pad || !pad.id || !pad.atext || !pad.pool) {
-    throw new Error('Invalid pad');
-  }
-
-  const range = pad.getValidRevisionRange(fromRev, toRev);
-  if (!range) throw new Error(`Invalid revision range. startRev: ${fromRev} endRev: ${toRev}`);
-
-  this._pad = pad;
-  this._fromRev = range.startRev;
-  this._toRev = range.endRev;
-  this._html = null;
-  this._authors = [];
-}
-
-PadDiff.prototype._isClearAuthorship = function (changeset) {
-  // unpack
-  const unpacked = Changeset.unpack(changeset);
-
-  // check if there is nothing in the charBank
-  if (unpacked.charBank !== '') {
-    return false;
-  }
-
-  // check if oldLength == newLength
-  if (unpacked.oldLen !== unpacked.newLen) {
-    return false;
-  }
-
-  const [clearOperator, anotherOp] = Changeset.deserializeOps(unpacked.ops);
-
-  // check if there is only one operator
-  if (anotherOp != null) return false;
-
-  // check if this operator doesn't change text
-  if (clearOperator.opcode !== '=') {
-    return false;
-  }
-
-  // check that this operator applys to the complete text
-  // if the text ends with a new line, its exactly one character less, else it has the same length
-  if (clearOperator.chars !== unpacked.oldLen - 1 && clearOperator.chars !== unpacked.oldLen) {
-    return false;
-  }
-
-  const [appliedAttribute, anotherAttribute] =
-      attributes.attribsFromString(clearOperator.attribs, this._pad.pool);
-
-  // Check that the operation has exactly one attribute.
-  if (appliedAttribute == null || anotherAttribute != null) return false;
-
-  // check if the applied attribute is an anonymous author attribute
-  if (appliedAttribute[0] !== 'author' || appliedAttribute[1] !== '') {
-    return false;
-  }
-
-  return true;
-};
-
-PadDiff.prototype._createClearAuthorship = async function (rev) {
-  const atext = await this._pad.getInternalRevisionAText(rev);
-
-  // build clearAuthorship changeset
-  const builder = Changeset.builder(atext.text.length);
-  builder.keepText(atext.text, [['author', '']], this._pad.pool);
-  const changeset = builder.toString();
-
-  return changeset;
-};
-
-PadDiff.prototype._createClearStartAtext = async function (rev) {
-  // get the atext of this revision
-  const atext = await this._pad.getInternalRevisionAText(rev);
-
-  // create the clearAuthorship changeset
-  const changeset = await this._createClearAuthorship(rev);
-
-  // apply the clearAuthorship changeset
-  const newAText = Changeset.applyToAText(changeset, atext, this._pad.pool);
-
-  return newAText;
-};
-
-PadDiff.prototype._getChangesetsInBulk = async function (startRev, count) {
-  // find out which revisions we need
-  const revisions = [];
-  for (let i = startRev; i < (startRev + count) && i <= this._pad.head; i++) {
-    revisions.push(i);
-  }
-
-  // get all needed revisions (in parallel)
-  const changesets = []; const
-    authors = [];
-  await Promise.all(revisions.map((rev) => this._pad.getRevision(rev).then((revision) => {
-    const arrayNum = rev - startRev;
-    changesets[arrayNum] = revision.changeset;
-    authors[arrayNum] = revision.meta.author;
-  })));
-
-  return {changesets, authors};
-};
-
-PadDiff.prototype._addAuthors = function (authors) {
-  const self = this;
-
-  // add to array if not in the array
-  authors.forEach((author) => {
-    if (self._authors.indexOf(author) === -1) {
-      self._authors.push(author);
-    }
-  });
-};
-
-PadDiff.prototype._createDiffAtext = async function () {
-  const bulkSize = 100;
-
-  // get the cleaned startAText
-  let atext = await this._createClearStartAtext(this._fromRev);
-
-  let superChangeset = null;
-
-  for (let rev = this._fromRev + 1; rev <= this._toRev; rev += bulkSize) {
-    // get the bulk
-    const {changesets, authors} = await this._getChangesetsInBulk(rev, bulkSize);
-
-    const addedAuthors = [];
-
-    // run through all changesets
-    for (let i = 0; i < changesets.length && (rev + i) <= this._toRev; ++i) {
-      let changeset = changesets[i];
-
-      // skip clearAuthorship Changesets
-      if (this._isClearAuthorship(changeset)) {
-        continue;
-      }
-
-      changeset = this._extendChangesetWithAuthor(changeset, authors[i], this._pad.pool);
-
-      // add this author to the authorarray
-      addedAuthors.push(authors[i]);
-
-      // compose it with the superChangset
-      if (superChangeset == null) {
-        superChangeset = changeset;
-      } else {
-        superChangeset = Changeset.compose(superChangeset, changeset, this._pad.pool);
-      }
-    }
-
-    // add the authors to the PadDiff authorArray
-    this._addAuthors(addedAuthors);
-  }
-
-  // if there are only clearAuthorship changesets, we don't get a superChangeset,
-  // so we can skip this step
-  if (superChangeset) {
-    const deletionChangeset = this._createDeletionChangeset(superChangeset, atext, this._pad.pool);
-
-    // apply the superChangeset, which includes all addings
-    atext = Changeset.applyToAText(superChangeset, atext, this._pad.pool);
-
-    // apply the deletionChangeset, which adds a deletions
-    atext = Changeset.applyToAText(deletionChangeset, atext, this._pad.pool);
-  }
-
-  return atext;
-};
-
-PadDiff.prototype.getHtml = async function () {
-  // cache the html
-  if (this._html != null) {
-    return this._html;
-  }
-
-  // get the diff atext
-  const atext = await this._createDiffAtext();
-
-  // get the authorColor table
-  const authorColors = await this._pad.getAllAuthorColors();
-
-  // convert the atext to html
-  this._html = await exportHtml.getHTMLFromAtext(this._pad, atext, authorColors);
-
-  return this._html;
-};
-
-PadDiff.prototype.getAuthors = async function () {
-  // check if html was already produced, if not produce it, this generates
-  // the author array at the same time
-  if (this._html == null) {
-    await this.getHtml();
-  }
-
-  return self._authors;
-};
-
-PadDiff.prototype._extendChangesetWithAuthor = (changeset, author, apool) => {
-  // unpack
-  const unpacked = Changeset.unpack(changeset);
-
-  const assem = Changeset.opAssembler();
-
-  // create deleted attribs
-  const authorAttrib = apool.putAttrib(['author', author || '']);
-  const deletedAttrib = apool.putAttrib(['removed', true]);
-  const attribs = `*${Changeset.numToString(authorAttrib)}*${Changeset.numToString(deletedAttrib)}`;
-
-  for (const operator of Changeset.deserializeOps(unpacked.ops)) {
-    if (operator.opcode === '-') {
-      // this is a delete operator, extend it with the author
-      operator.attribs = attribs;
-    } else if (operator.opcode === '=' && operator.attribs) {
-      // this is operator changes only attributes, let's mark which author did that
-      operator.attribs += `*${Changeset.numToString(authorAttrib)}`;
-    }
-
-    // append the new operator to our assembler
-    assem.append(operator);
-  }
-
-  // return the modified changeset
-  return Changeset.pack(unpacked.oldLen, unpacked.newLen, assem.toString(), unpacked.charBank);
-};
-
-// this method is 80% like Changeset.inverse. I just changed so instead of reverting,
-// it adds deletions and attribute changes to to the atext.
-PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
-  const lines = Changeset.splitTextLines(startAText.text);
-  const alines = Changeset.splitAttributionLines(startAText.attribs, startAText.text);
-
-  // lines and alines are what the exports is meant to apply to.
-  // They may be arrays or objects with .get(i) and .length methods.
-  // They include final newlines on lines.
-
-  const linesGet = (idx) => {
-    if (lines.get) {
-      return lines.get(idx);
-    } else {
-      return lines[idx];
-    }
-  };
-
-  const aLinesGet = (idx) => {
-    if (alines.get) {
-      return alines.get(idx);
-    } else {
-      return alines[idx];
-    }
-  };
-
-  let curLine = 0;
-  let curChar = 0;
-  let curLineOps = null;
-  let curLineOpsNext = null;
-  let curLineOpsLine;
-  let curLineNextOp = new Changeset.Op('+');
-
-  const unpacked = Changeset.unpack(cs);
-  const builder = Changeset.builder(unpacked.newLen);
-
-  const consumeAttribRuns = (numChars, func /* (len, attribs, endsLine)*/) => {
-    if (!curLineOps || curLineOpsLine !== curLine) {
-      curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
-      curLineOpsNext = curLineOps.next();
-      curLineOpsLine = curLine;
-      let indexIntoLine = 0;
-      while (!curLineOpsNext.done) {
-        curLineNextOp = curLineOpsNext.value;
-        curLineOpsNext = curLineOps.next();
-        if (indexIntoLine + curLineNextOp.chars >= curChar) {
-          curLineNextOp.chars -= (curChar - indexIntoLine);
-          break;
-        }
-        indexIntoLine += curLineNextOp.chars;
-      }
-    }
-
-    while (numChars > 0) {
-      if (!curLineNextOp.chars && curLineOpsNext.done) {
-        curLine++;
-        curChar = 0;
-        curLineOpsLine = curLine;
-        curLineNextOp.chars = 0;
-        curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
-        curLineOpsNext = curLineOps.next();
-      }
-
-      if (!curLineNextOp.chars) {
-        if (curLineOpsNext.done) {
-          curLineNextOp = new Changeset.Op();
-        } else {
-          curLineNextOp = curLineOpsNext.value;
-          curLineOpsNext = curLineOps.next();
-        }
-      }
-
-      const charsToUse = Math.min(numChars, curLineNextOp.chars);
-
-      func(charsToUse, curLineNextOp.attribs,
-          charsToUse === curLineNextOp.chars && curLineNextOp.lines > 0);
-      numChars -= charsToUse;
-      curLineNextOp.chars -= charsToUse;
-      curChar += charsToUse;
-    }
-
-    if (!curLineNextOp.chars && curLineOpsNext.done) {
-      curLine++;
-      curChar = 0;
-    }
-  };
-
-  const skip = (N, L) => {
-    if (L) {
-      curLine += L;
-      curChar = 0;
-    } else if (curLineOps && curLineOpsLine === curLine) {
-      consumeAttribRuns(N, () => {});
-    } else {
-      curChar += N;
-    }
-  };
-
-  const nextText = (numChars) => {
-    let len = 0;
-    const assem = Changeset.stringAssembler();
-    const firstString = linesGet(curLine).substring(curChar);
-    len += firstString.length;
-    assem.append(firstString);
-
-    let lineNum = curLine + 1;
-
-    while (len < numChars) {
-      const nextString = linesGet(lineNum);
-      len += nextString.length;
-      assem.append(nextString);
-      lineNum++;
-    }
-
-    return assem.toString().substring(0, numChars);
-  };
-
-  const cachedStrFunc = (func) => {
-    const cache = {};
-
-    return (s) => {
-      if (!cache[s]) {
-        cache[s] = func(s);
-      }
-      return cache[s];
-    };
-  };
-
-  for (const csOp of Changeset.deserializeOps(unpacked.ops)) {
-    if (csOp.opcode === '=') {
-      const textBank = nextText(csOp.chars);
-
-      // decide if this equal operator is an attribution change or not.
-      // We can see this by checkinf if attribs is set.
-      // If the text this operator applies to is only a star,
-      // than this is a false positive and should be ignored
-      if (csOp.attribs && textBank !== '*') {
-        const attribs = AttributeMap.fromString(csOp.attribs, apool);
-        const undoBackToAttribs = cachedStrFunc((oldAttribsStr) => {
-          const oldAttribs = AttributeMap.fromString(oldAttribsStr, apool);
-          const backAttribs = new AttributeMap(apool)
-              .set('author', '')
-              .set('removed', 'true');
-          for (const [key, value] of attribs) {
-            const oldValue = oldAttribs.get(key);
-            if (oldValue !== value) backAttribs.set(key, oldValue);
-          }
-          // TODO: backAttribs does not restore removed attributes (it is missing attributes that
-          // are in oldAttribs but not in attribs). I don't know if that is intentional.
-          return backAttribs.toString();
-        });
-
-        let textLeftToProcess = textBank;
-
-        while (textLeftToProcess.length > 0) {
-          // process till the next line break or process only one line break
-          let lengthToProcess = textLeftToProcess.indexOf('\n');
-          let lineBreak = false;
-          switch (lengthToProcess) {
-            case -1:
-              lengthToProcess = textLeftToProcess.length;
-              break;
-            case 0:
-              lineBreak = true;
-              lengthToProcess = 1;
-              break;
-          }
-
-          // get the text we want to procceed in this step
-          const processText = textLeftToProcess.substr(0, lengthToProcess);
-
-          textLeftToProcess = textLeftToProcess.substr(lengthToProcess);
-
-          if (lineBreak) {
-            builder.keep(1, 1); // just skip linebreaks, don't do a insert + keep for a linebreak
-
-            // consume the attributes of this linebreak
-            consumeAttribRuns(1, () => {});
-          } else {
-            // add the old text via an insert, but add a deletion attribute +
-            // the author attribute of the author who deleted it
-            let textBankIndex = 0;
-            consumeAttribRuns(lengthToProcess, (len, attribs, endsLine) => {
-              // get the old attributes back
-              const oldAttribs = undoBackToAttribs(attribs);
-
-              builder.insert(processText.substr(textBankIndex, len), oldAttribs);
-              textBankIndex += len;
-            });
-
-            builder.keep(lengthToProcess, 0);
-          }
-        }
-      } else {
-        skip(csOp.chars, csOp.lines);
-        builder.keep(csOp.chars, csOp.lines);
-      }
-    } else if (csOp.opcode === '+') {
-      builder.keep(csOp.chars, csOp.lines);
-    } else if (csOp.opcode === '-') {
-      const textBank = nextText(csOp.chars);
-      let textBankIndex = 0;
-
-      consumeAttribRuns(csOp.chars, (len, attribs, endsLine) => {
-        builder.insert(textBank.substr(textBankIndex, len), attribs + csOp.attribs);
-        textBankIndex += len;
-      });
-    }
-  }
-
-  return Changeset.checkRep(builder.toString());
-};
-
-// export the constructor
-module.exports = PadDiff;
diff --git a/src/node/utils/padDiff.ts b/src/node/utils/padDiff.ts
new file mode 100644
index 000000000..cd29aeb7a
--- /dev/null
+++ b/src/node/utils/padDiff.ts
@@ -0,0 +1,458 @@
+'use strict';
+
+import {PadAuthor, PadType} from "../types/PadType";
+import {MapArrayType} from "../types/MapType";
+
+const AttributeMap = require('../../static/js/AttributeMap');
+const Changeset = require('../../static/js/Changeset');
+const attributes = require('../../static/js/attributes');
+const exportHtml = require('./ExportHtml');
+
+
+class PadDiff {
+  private readonly _pad: PadType;
+    private readonly _fromRev: string;
+    private readonly _toRev: string;
+    private _html: any;
+    public _authors: any[];
+    private self: PadDiff | undefined
+  constructor(pad: PadType, fromRev:string, toRev:string) {
+    // check parameters
+    if (!pad || !pad.id || !pad.atext || !pad.pool) {
+      throw new Error('Invalid pad');
+    }
+
+    const range = pad.getValidRevisionRange(fromRev, toRev);
+    if (!range) throw new Error(`Invalid revision range. startRev: ${fromRev} endRev: ${toRev}`);
+
+    this._pad = pad;
+    this._fromRev = range.startRev;
+    this._toRev = range.endRev;
+    this._html = null;
+    this._authors = [];
+  }
+  _isClearAuthorship(changeset: any){
+    // unpack
+    const unpacked = Changeset.unpack(changeset);
+
+    // check if there is nothing in the charBank
+    if (unpacked.charBank !== '') {
+      return false;
+    }
+
+    // check if oldLength == newLength
+    if (unpacked.oldLen !== unpacked.newLen) {
+      return false;
+    }
+
+    const [clearOperator, anotherOp] = Changeset.deserializeOps(unpacked.ops);
+
+    // check if there is only one operator
+    if (anotherOp != null) return false;
+
+    // check if this operator doesn't change text
+    if (clearOperator.opcode !== '=') {
+      return false;
+    }
+
+    // check that this operator applys to the complete text
+    // if the text ends with a new line, its exactly one character less, else it has the same length
+    if (clearOperator.chars !== unpacked.oldLen - 1 && clearOperator.chars !== unpacked.oldLen) {
+      return false;
+    }
+
+    const [appliedAttribute, anotherAttribute] =
+        attributes.attribsFromString(clearOperator.attribs, this._pad.pool);
+
+    // Check that the operation has exactly one attribute.
+    if (appliedAttribute == null || anotherAttribute != null) return false;
+
+    // check if the applied attribute is an anonymous author attribute
+    if (appliedAttribute[0] !== 'author' || appliedAttribute[1] !== '') {
+      return false;
+    }
+
+    return true;
+  }
+  async _createClearAuthorship(rev: any){
+    const atext = await this._pad.getInternalRevisionAText(rev);
+
+    // build clearAuthorship changeset
+    const builder = Changeset.builder(atext.text.length);
+    builder.keepText(atext.text, [['author', '']], this._pad.pool);
+    const changeset = builder.toString();
+
+    return changeset;
+  }
+
+  async _createClearStartAtext(rev: any){
+    // get the atext of this revision
+    const atext = await this._pad.getInternalRevisionAText(rev);
+
+    // create the clearAuthorship changeset
+    const changeset = await this._createClearAuthorship(rev);
+
+    // apply the clearAuthorship changeset
+    const newAText = Changeset.applyToAText(changeset, atext, this._pad.pool);
+
+    return newAText;
+  }
+  async _getChangesetsInBulk(startRev: any, count: any) {
+    // find out which revisions we need
+    const revisions = [];
+    for (let i = startRev; i < (startRev + count) && i <= this._pad.head; i++) {
+      revisions.push(i);
+    }
+
+    // get all needed revisions (in parallel)
+    const changesets:any[] = [];
+    const authors: any[] = [];
+    await Promise.all(revisions.map((rev) => this._pad.getRevision(rev).then((revision) => {
+      const arrayNum = rev - startRev;
+      changesets[arrayNum] = revision.changeset;
+      authors[arrayNum] = revision.meta.author;
+    })));
+
+    return {changesets, authors};
+  }
+  _addAuthors(authors: PadAuthor[]){
+      this.self = this;
+
+    // add to array if not in the array
+    authors.forEach((author) => {
+      if (this.self!._authors.indexOf(author) === -1) {
+        this.self!._authors.push(author);
+      }
+    });
+  }
+  async _createDiffAtext(){
+    const bulkSize = 100;
+
+    // get the cleaned startAText
+    let atext = await this._createClearStartAtext(this._fromRev);
+
+    let superChangeset = null;
+
+    for (let rev = this._fromRev + 1; rev <= this._toRev; rev += bulkSize) {
+      // get the bulk
+      const {changesets, authors} = await this._getChangesetsInBulk(rev, bulkSize);
+
+      const addedAuthors = [];
+
+      // run through all changesets
+      for (let i = 0; i < changesets.length && (rev + i) <= this._toRev; ++i) {
+        let changeset = changesets[i];
+
+        // skip clearAuthorship Changesets
+        if (this._isClearAuthorship(changeset)) {
+          continue;
+        }
+
+        changeset = this._extendChangesetWithAuthor(changeset, authors[i], this._pad.pool);
+
+        // add this author to the authorarray
+        addedAuthors.push(authors[i]);
+
+        // compose it with the superChangset
+        if (superChangeset == null) {
+          superChangeset = changeset;
+        } else {
+          superChangeset = Changeset.compose(superChangeset, changeset, this._pad.pool);
+        }
+      }
+
+      // add the authors to the PadDiff authorArray
+      this._addAuthors(addedAuthors);
+    }
+
+    // if there are only clearAuthorship changesets, we don't get a superChangeset,
+    // so we can skip this step
+    if (superChangeset) {
+      const deletionChangeset = this._createDeletionChangeset(superChangeset, atext, this._pad.pool);
+
+      // apply the superChangeset, which includes all addings
+      atext = Changeset.applyToAText(superChangeset, atext, this._pad.pool);
+
+      // apply the deletionChangeset, which adds a deletions
+      atext = Changeset.applyToAText(deletionChangeset, atext, this._pad.pool);
+    }
+
+    return atext;
+  }
+  async getHtml(){
+    // cache the html
+    if (this._html != null) {
+      return this._html;
+    }
+
+    // get the diff atext
+    const atext = await this._createDiffAtext();
+
+    // get the authorColor table
+    const authorColors = await this._pad.getAllAuthorColors();
+
+    // convert the atext to html
+    this._html = await exportHtml.getHTMLFromAtext(this._pad, atext, authorColors);
+
+    return this._html;
+  }
+
+  async getAuthors() {
+    // check if html was already produced, if not produce it, this generates
+    // the author array at the same time
+    if (this._html == null) {
+      await this.getHtml();
+    }
+
+    return this.self!._authors;
+  }
+
+  _extendChangesetWithAuthor(changeset: any, author: any, apool: any){
+    // unpack
+    const unpacked = Changeset.unpack(changeset);
+
+    const assem = Changeset.opAssembler();
+
+    // create deleted attribs
+    const authorAttrib = apool.putAttrib(['author', author || '']);
+    const deletedAttrib = apool.putAttrib(['removed', true]);
+    const attribs = `*${Changeset.numToString(authorAttrib)}*${Changeset.numToString(deletedAttrib)}`;
+
+    for (const operator of Changeset.deserializeOps(unpacked.ops)) {
+      if (operator.opcode === '-') {
+        // this is a delete operator, extend it with the author
+        operator.attribs = attribs;
+      } else if (operator.opcode === '=' && operator.attribs) {
+        // this is operator changes only attributes, let's mark which author did that
+        operator.attribs += `*${Changeset.numToString(authorAttrib)}`;
+      }
+
+      // append the new operator to our assembler
+      assem.append(operator);
+    }
+
+    // return the modified changeset
+    return Changeset.pack(unpacked.oldLen, unpacked.newLen, assem.toString(), unpacked.charBank);
+  }
+  _createDeletionChangeset(cs: any, startAText: any, apool: any){
+    const lines = Changeset.splitTextLines(startAText.text);
+    const alines = Changeset.splitAttributionLines(startAText.attribs, startAText.text);
+
+    // lines and alines are what the exports is meant to apply to.
+    // They may be arrays or objects with .get(i) and .length methods.
+    // They include final newlines on lines.
+
+    const linesGet = (idx: number) => {
+      if (lines.get) {
+        return lines.get(idx);
+      } else {
+        return lines[idx];
+      }
+    };
+
+    const aLinesGet = (idx: number) => {
+      if (alines.get) {
+        return alines.get(idx);
+      } else {
+        return alines[idx];
+      }
+    };
+
+    let curLine = 0;
+    let curChar = 0;
+    let curLineOps: { next: () => any; } | null = null;
+    let curLineOpsNext: { done: any; value: any; } | null = null;
+    let curLineOpsLine: number;
+    let curLineNextOp = new Changeset.Op('+');
+
+    const unpacked = Changeset.unpack(cs);
+    const builder = Changeset.builder(unpacked.newLen);
+
+    const consumeAttribRuns = (numChars: number, func: Function /* (len, attribs, endsLine)*/) => {
+      if (!curLineOps || curLineOpsLine !== curLine) {
+        curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
+        curLineOpsNext = curLineOps!.next();
+        curLineOpsLine = curLine;
+        let indexIntoLine = 0;
+        while (!curLineOpsNext!.done) {
+          curLineNextOp = curLineOpsNext!.value;
+          curLineOpsNext = curLineOps!.next();
+          if (indexIntoLine + curLineNextOp.chars >= curChar) {
+            curLineNextOp.chars -= (curChar - indexIntoLine);
+            break;
+          }
+          indexIntoLine += curLineNextOp.chars;
+        }
+      }
+
+      while (numChars > 0) {
+        if (!curLineNextOp.chars && curLineOpsNext!.done) {
+          curLine++;
+          curChar = 0;
+          curLineOpsLine = curLine;
+          curLineNextOp.chars = 0;
+          curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
+          curLineOpsNext = curLineOps!.next();
+        }
+
+        if (!curLineNextOp.chars) {
+          if (curLineOpsNext!.done) {
+            curLineNextOp = new Changeset.Op();
+          } else {
+            curLineNextOp = curLineOpsNext!.value;
+            curLineOpsNext = curLineOps!.next();
+          }
+        }
+
+        const charsToUse = Math.min(numChars, curLineNextOp.chars);
+
+        func(charsToUse, curLineNextOp.attribs,
+            charsToUse === curLineNextOp.chars && curLineNextOp.lines > 0);
+        numChars -= charsToUse;
+        curLineNextOp.chars -= charsToUse;
+        curChar += charsToUse;
+      }
+
+      if (!curLineNextOp.chars && curLineOpsNext!.done) {
+        curLine++;
+        curChar = 0;
+      }
+    };
+
+    const skip = (N:number, L:number) => {
+      if (L) {
+        curLine += L;
+        curChar = 0;
+      } else if (curLineOps && curLineOpsLine === curLine) {
+        consumeAttribRuns(N, () => {});
+      } else {
+        curChar += N;
+      }
+    };
+
+    const nextText = (numChars: number) => {
+      let len = 0;
+      const assem = Changeset.stringAssembler();
+      const firstString = linesGet(curLine).substring(curChar);
+      len += firstString.length;
+      assem.append(firstString);
+
+      let lineNum = curLine + 1;
+
+      while (len < numChars) {
+        const nextString = linesGet(lineNum);
+        len += nextString.length;
+        assem.append(nextString);
+        lineNum++;
+      }
+
+      return assem.toString().substring(0, numChars);
+    };
+
+    const cachedStrFunc = (func:Function) => {
+      const cache:MapArrayType<any> = {};
+
+      return (s:string) => {
+        if (!cache[s]) {
+          cache[s] = func(s);
+        }
+        return cache[s];
+      };
+    };
+
+    for (const csOp of Changeset.deserializeOps(unpacked.ops)) {
+      if (csOp.opcode === '=') {
+        const textBank = nextText(csOp.chars);
+
+        // decide if this equal operator is an attribution change or not.
+        // We can see this by checkinf if attribs is set.
+        // If the text this operator applies to is only a star,
+        // than this is a false positive and should be ignored
+        if (csOp.attribs && textBank !== '*') {
+          const attribs = AttributeMap.fromString(csOp.attribs, apool);
+          const undoBackToAttribs = cachedStrFunc((oldAttribsStr: string) => {
+            const oldAttribs = AttributeMap.fromString(oldAttribsStr, apool);
+            const backAttribs = new AttributeMap(apool)
+                .set('author', '')
+                .set('removed', 'true');
+            for (const [key, value] of attribs) {
+              const oldValue = oldAttribs.get(key);
+              if (oldValue !== value) backAttribs.set(key, oldValue);
+            }
+            // TODO: backAttribs does not restore removed attributes (it is missing attributes that
+            // are in oldAttribs but not in attribs). I don't know if that is intentional.
+            return backAttribs.toString();
+          });
+
+          let textLeftToProcess = textBank;
+
+          while (textLeftToProcess.length > 0) {
+            // process till the next line break or process only one line break
+            let lengthToProcess = textLeftToProcess.indexOf('\n');
+            let lineBreak = false;
+            switch (lengthToProcess) {
+              case -1:
+                lengthToProcess = textLeftToProcess.length;
+                break;
+              case 0:
+                lineBreak = true;
+                lengthToProcess = 1;
+                break;
+            }
+
+            // get the text we want to procceed in this step
+            const processText = textLeftToProcess.substr(0, lengthToProcess);
+
+            textLeftToProcess = textLeftToProcess.substr(lengthToProcess);
+
+            if (lineBreak) {
+              builder.keep(1, 1); // just skip linebreaks, don't do a insert + keep for a linebreak
+
+              // consume the attributes of this linebreak
+              consumeAttribRuns(1, () => {});
+            } else {
+              // add the old text via an insert, but add a deletion attribute +
+              // the author attribute of the author who deleted it
+              let textBankIndex = 0;
+              consumeAttribRuns(lengthToProcess, (len: number, attribs:string, endsLine: string) => {
+                // get the old attributes back
+                const oldAttribs = undoBackToAttribs(attribs);
+
+                builder.insert(processText.substr(textBankIndex, len), oldAttribs);
+                textBankIndex += len;
+              });
+
+              builder.keep(lengthToProcess, 0);
+            }
+          }
+        } else {
+          skip(csOp.chars, csOp.lines);
+          builder.keep(csOp.chars, csOp.lines);
+        }
+      } else if (csOp.opcode === '+') {
+        builder.keep(csOp.chars, csOp.lines);
+      } else if (csOp.opcode === '-') {
+        const textBank = nextText(csOp.chars);
+        let textBankIndex = 0;
+
+        consumeAttribRuns(csOp.chars, (len: number, attribs: string[], endsLine: string) => {
+          builder.insert(textBank.substr(textBankIndex, len), attribs + csOp.attribs);
+          textBankIndex += len;
+        });
+      }
+    }
+
+    return Changeset.checkRep(builder.toString());
+  }
+
+}
+
+
+// this method is 80% like Changeset.inverse. I just changed so instead of reverting,
+// it adds deletions and attribute changes to to the atext.
+PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
+
+};
+
+// export the constructor
+module.exports = PadDiff;