diff --git a/src/controllers/write/categories.js b/src/controllers/write/categories.js
index bb4ec84090..32510c50ad 100644
--- a/src/controllers/write/categories.js
+++ b/src/controllers/write/categories.js
@@ -1,107 +1,109 @@
-'use strict';
-
-const categories = require('../../categories');
-const meta = require('../../meta');
-const api = require('../../api');
-
-const helpers = require('../helpers');
-
-const Categories = module.exports;
-
-Categories.list = async (req, res) => {
-	helpers.formatApiResponse(200, res, await api.categories.list(req));
+"use strict";
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
 };
-
-Categories.get = async (req, res) => {
-	helpers.formatApiResponse(200, res, await api.categories.get(req, req.params));
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.delete = exports.setModerator = exports.setPrivilege = exports.getPrivileges = exports.setWatchState = exports.getTopics = exports.getChildren = exports.getPosts = exports.getTopicCount = exports.deleteCategories = exports.update = exports.create = exports.get = exports.list = void 0;
+const categories_1 = __importDefault(require("../../categories"));
+const meta_1 = __importDefault(require("../../meta"));
+const api_1 = __importDefault(require("../../api"));
+const helpers_1 = __importDefault(require("../helpers"));
+const list = async (req, res) => {
+    await helpers_1.default.formatApiResponse(200, res, await api_1.default.categories.list(req));
 };
-
-Categories.create = async (req, res) => {
-	const response = await api.categories.create(req, req.body);
-	helpers.formatApiResponse(200, res, response);
+exports.list = list;
+const get = async (req, res) => {
+    await helpers_1.default.formatApiResponse(200, res, await api_1.default.categories.get(req, req.params));
 };
-
-Categories.update = async (req, res) => {
-	await api.categories.update(req, {
-		cid: req.params.cid,
-		values: req.body,
-	});
-
-	const categoryObjs = await categories.getCategories([req.params.cid]);
-	helpers.formatApiResponse(200, res, categoryObjs[0]);
+exports.get = get;
+const create = async (req, res) => {
+    const response = await api_1.default.categories.create(req, req.body);
+    await helpers_1.default.formatApiResponse(200, res, response);
 };
-
-Categories.delete = async (req, res) => {
-	await api.categories.delete(req, { cid: req.params.cid });
-	helpers.formatApiResponse(200, res);
+exports.create = create;
+const update = async (req, res) => {
+    await api_1.default.categories.update(req, {
+        cid: req.params.cid,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+        values: req.body,
+    });
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+    const categoryObjs = await categories_1.default.getCategories([req.params.cid]);
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+    await helpers_1.default.formatApiResponse(200, res, categoryObjs[0]);
 };
-
-Categories.getTopicCount = async (req, res) => {
-	helpers.formatApiResponse(200, res, await api.categories.getTopicCount(req, { ...req.params }));
+exports.update = update;
+const deleteCategories = async (req, res) => {
+    await api_1.default.categories.delete(req, { cid: req.params.cid });
+    await helpers_1.default.formatApiResponse(200, res);
 };
-
-Categories.getPosts = async (req, res) => {
-	const posts = await api.categories.getPosts(req, { ...req.params });
-	helpers.formatApiResponse(200, res, { posts });
+exports.deleteCategories = deleteCategories;
+exports.delete = exports.deleteCategories;
+const getTopicCount = async (req, res) => {
+    await helpers_1.default.formatApiResponse(200, res, await api_1.default.categories.getTopicCount(req, Object.assign({}, req.params)));
 };
-
-Categories.getChildren = async (req, res) => {
-	const { cid } = req.params;
-	const { start } = req.query;
-	helpers.formatApiResponse(200, res, await api.categories.getChildren(req, { cid, start }));
+exports.getTopicCount = getTopicCount;
+const getPosts = async (req, res) => {
+    const posts = await api_1.default.categories.getPosts(req, Object.assign({}, req.params));
+    await helpers_1.default.formatApiResponse(200, res, { posts });
 };
-
-Categories.getTopics = async (req, res) => {
-	const { cid } = req.params;
-	const result = await api.categories.getTopics(req, { ...req.query, cid });
-
-	helpers.formatApiResponse(200, res, result);
+exports.getPosts = getPosts;
+const getChildren = async (req, res) => {
+    const { cid } = req.params;
+    const { start } = req.query;
+    await helpers_1.default.formatApiResponse(200, res, await api_1.default.categories.getChildren(req, { cid, start }));
 };
-
-Categories.setWatchState = async (req, res) => {
-	const { cid } = req.params;
-	let { uid, state } = req.body;
-
-	if (req.method === 'DELETE') {
-		// DELETE is always setting state to system default in acp
-		state = categories.watchStates[meta.config.categoryWatchState];
-	} else if (Object.keys(categories.watchStates).includes(state)) {
-		state = categories.watchStates[state]; // convert to integer for backend processing
-	} else {
-		throw new Error('[[error:invalid-data]]');
-	}
-
-	const { cids: modified } = await api.categories.setWatchState(req, { cid, state, uid });
-
-	helpers.formatApiResponse(200, res, { modified });
+exports.getChildren = getChildren;
+const getTopics = async (req, res) => {
+    const { cid } = req.params;
+    const result = await api_1.default.categories.getTopics(req, Object.assign(Object.assign({}, req.query), { cid }));
+    await helpers_1.default.formatApiResponse(200, res, result);
 };
-
-Categories.getPrivileges = async (req, res) => {
-	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
-	helpers.formatApiResponse(200, res, privilegeSet);
+exports.getTopics = getTopics;
+const setWatchState = async (req, res) => {
+    const { cid } = req.params;
+    let { uid, state } = req.body;
+    if (req.method === 'DELETE') {
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+        state = categories_1.default.watchStates[meta_1.default.config.categoryWatchState];
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-argument
+    }
+    else if (Object.keys(categories_1.default.watchStates).includes(state)) {
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+        state = categories_1.default.watchStates[state];
+    }
+    else {
+        throw new Error('[[error:invalid-data]]');
+    }
+    const { cids: modified } = await api_1.default.categories.setWatchState(req, { cid, state, uid });
+    await helpers_1.default.formatApiResponse(200, res, { modified });
 };
-
-Categories.setPrivilege = async (req, res) => {
-	const { cid, privilege } = req.params;
-
-	await api.categories.setPrivilege(req, {
-		cid,
-		privilege,
-		member: req.body.member,
-		set: req.method === 'PUT',
-	});
-
-	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
-	helpers.formatApiResponse(200, res, privilegeSet);
+exports.setWatchState = setWatchState;
+const getPrivileges = async (req, res) => {
+    const privilegeSet = await api_1.default.categories.getPrivileges(req, { cid: req.params.cid });
+    await helpers_1.default.formatApiResponse(200, res, privilegeSet);
 };
-
-Categories.setModerator = async (req, res) => {
-	await api.categories.setModerator(req, {
-		cid: req.params.cid,
-		member: req.params.uid,
-		set: req.method === 'PUT',
-	});
-
-	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
-	helpers.formatApiResponse(200, res, privilegeSet);
+exports.getPrivileges = getPrivileges;
+const setPrivilege = async (req, res) => {
+    const { cid, privilege } = req.params;
+    await api_1.default.categories.setPrivilege(req, {
+        cid,
+        privilege,
+        // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+        member: req.body.member,
+        set: req.method === 'PUT',
+    });
+    const privilegeSet = await api_1.default.categories.getPrivileges(req, { cid: req.params.cid });
+    await helpers_1.default.formatApiResponse(200, res, privilegeSet);
 };
+exports.setPrivilege = setPrivilege;
+const setModerator = async (req, res) => {
+    await api_1.default.categories.setModerator(req, {
+        cid: req.params.cid,
+        member: req.params.uid,
+        set: req.method === 'PUT',
+    });
+    const privilegeSet = await api_1.default.categories.getPrivileges(req, { cid: req.params.cid });
+    await helpers_1.default.formatApiResponse(200, res, privilegeSet);
+};
+exports.setModerator = setModerator;
diff --git a/src/controllers/write/categories.ts b/src/controllers/write/categories.ts
new file mode 100644
index 0000000000..4df5394be0
--- /dev/null
+++ b/src/controllers/write/categories.ts
@@ -0,0 +1,129 @@
+import categories from '../../categories';
+import meta from '../../meta';
+import api from '../../api';
+import helpers from '../helpers';
+// Interfaces
+
+interface Params {
+    cid: string;
+    privilege?: string;
+    uid?: string;
+}
+
+interface Request {
+    params: Params;
+    body: any;
+    query: { start?: number };
+    method: string;
+}
+
+interface Response {
+    status: (code: number) => void;
+    json: (data: any) => void;
+}
+
+interface WatchStateRequest extends Request {
+    body: {
+        uid: string;
+        state: string;
+    };
+}
+
+export const list = async (req: Request, res: Response) => {
+	await helpers.formatApiResponse(200, res, await api.categories.list(req));
+};
+
+export const get = async (req: Request, res: Response): Promise<void> => {
+	await helpers.formatApiResponse(200, res, await api.categories.get(req, req.params));
+};
+
+export const create = async (req: Request, res: Response): Promise<void> => {
+	const response: unknown = await api.categories.create(req, req.body);
+	await helpers.formatApiResponse(200, res, response);
+};
+
+export const update = async (req: Request, res: Response): Promise<void> => {
+	await api.categories.update(req, {
+		cid: req.params.cid,
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+		values: req.body,
+	});
+	// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+	const categoryObjs = await categories.getCategories([req.params.cid]);
+	// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+	await helpers.formatApiResponse(200, res, categoryObjs[0]);
+};
+
+export const deleteCategories = async (req: Request, res: Response): Promise<void> => {
+	await api.categories.delete(req, { cid: req.params.cid });
+	await helpers.formatApiResponse(200, res);
+};
+
+export const getTopicCount = async (req: Request, res: Response): Promise<void> => {
+	await helpers.formatApiResponse(200, res, await api.categories.getTopicCount(req, { ...req.params }));
+};
+
+export const getPosts = async (req: Request, res: Response): Promise<void> => {
+	const posts: unknown = await api.categories.getPosts(req, { ...req.params });
+	await helpers.formatApiResponse(200, res, { posts });
+};
+
+export const getChildren = async (req: Request, res: Response): Promise<void> => {
+	const { cid } = req.params;
+	const { start } = req.query;
+	await helpers.formatApiResponse(200, res, await api.categories.getChildren(req, { cid, start }));
+};
+
+export const getTopics = async (req: Request, res: Response): Promise<void> => {
+	const { cid } = req.params;
+	const result: unknown = await api.categories.getTopics(req, { ...req.query, cid });
+	await helpers.formatApiResponse(200, res, result);
+};
+
+export const setWatchState = async (req: WatchStateRequest, res: Response): Promise<void> => {
+	const { cid } = req.params;
+	let { uid, state } = req.body;
+
+	if (req.method === 'DELETE') {
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+		state = categories.watchStates[meta.config.categoryWatchState];
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-argument
+	} else if (Object.keys(categories.watchStates).includes(state)) {
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+		state = categories.watchStates[state];
+	} else {
+		throw new Error('[[error:invalid-data]]');
+	}
+
+	const { cids: modified } = await api.categories.setWatchState(req, { cid, state, uid });
+	await helpers.formatApiResponse(200, res, { modified });
+};
+
+export const getPrivileges = async (req: Request, res: Response): Promise<void> => {
+	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
+	await helpers.formatApiResponse(200, res, privilegeSet);
+};
+
+export const setPrivilege = async (req: Request, res: Response): Promise<void> => {
+	const { cid, privilege } = req.params;
+	await api.categories.setPrivilege(req, {
+		cid,
+		privilege,
+		// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-member-access
+		member: req.body.member,
+		set: req.method === 'PUT',
+	});
+	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
+	await helpers.formatApiResponse(200, res, privilegeSet);
+};
+
+export const setModerator = async (req: Request, res: Response): Promise<void> => {
+	await api.categories.setModerator(req, {
+		cid: req.params.cid,
+		member: req.params.uid,
+		set: req.method === 'PUT',
+	});
+	const privilegeSet = await api.categories.getPrivileges(req, { cid: req.params.cid });
+	await helpers.formatApiResponse(200, res, privilegeSet);
+};
+export { deleteCategories as delete };
diff --git a/src/dummy.js b/src/dummy.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tsconfig.json b/tsconfig.json
index 10aeeef7e6..529edaed8d 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,17 +1,17 @@
 {
   "compilerOptions": {
     "allowJs": false,
-    "target": "es6",
+    "target": "es2017",
     "module": "commonjs",
     "moduleResolution": "node",
     "esModuleInterop": true,
   },
   "include": [
     "public/src/**/*",
-    "src/**/*", 
+    "src/**/*",
     "test/**/*",
   ],
-  "exclude":[
+  "exclude": [
     "node_modules",
   ]
 }
\ No newline at end of file