diff --git a/lib/RegExp.coffee b/lib/RegExp.coffee
deleted file mode 100644
index c068aefc58d..00000000000
--- a/lib/RegExp.coffee
+++ /dev/null
@@ -1,2 +0,0 @@
-RegExp.escape = (s) ->
-	return s.replace /[-\/\\^$*+?.()|[\]{}]/g, '\\$&'
\ No newline at end of file
diff --git a/lib/RegExp.js b/lib/RegExp.js
new file mode 100644
index 00000000000..60d252508d3
--- /dev/null
+++ b/lib/RegExp.js
@@ -0,0 +1,3 @@
+RegExp.escape = function(s) {
+	return s.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
+};
diff --git a/lib/fileUpload.coffee b/lib/fileUpload.coffee
deleted file mode 100644
index ee0f2dc7504..00000000000
--- a/lib/fileUpload.coffee
+++ /dev/null
@@ -1,69 +0,0 @@
-if UploadFS?
-	RocketChat.models.Uploads.allow
-		insert: (userId, doc) ->
-			return userId
-
-		update: (userId, doc) ->
-			return userId is doc.userId
-
-		remove: (userId, doc) ->
-			return userId is doc.userId
-
-	initFileStore = ->
-		cookie = new Cookies()
-		if Meteor.isClient
-			document.cookie = 'rc_uid=' + escape(Meteor.userId()) + '; path=/'
-			document.cookie = 'rc_token=' + escape(Accounts._storedLoginToken()) + '; path=/'
-
-		Meteor.fileStore = new UploadFS.store.GridFS
-			collection: RocketChat.models.Uploads.model
-			name: 'rocketchat_uploads'
-			collectionName: 'rocketchat_uploads'
-			filter: new UploadFS.Filter
-				onCheck: FileUpload.validateFileUpload
-			transformWrite: (readStream, writeStream, fileId, file) ->
-				if RocketChatFile.enabled is false or not /^image\/.+/.test(file.type)
-					return readStream.pipe writeStream
-
-				stream = undefined
-
-				identify = (err, data) ->
-					if err?
-						return stream.pipe writeStream
-
-					file.identify =
-						format: data.format
-						size: data.size
-
-					if data.Orientation? and data.Orientation not in ['', 'Unknown', 'Undefined']
-						RocketChatFile.gm(stream).autoOrient().stream().pipe(writeStream)
-					else
-						stream.pipe writeStream
-
-				stream = RocketChatFile.gm(readStream).identify(identify).stream()
-
-			onRead: (fileId, file, req, res) ->
-				if RocketChat.settings.get 'FileUpload_ProtectFiles'
-					rawCookies = req.headers.cookie if req?.headers?.cookie?
-					uid = cookie.get('rc_uid', rawCookies) if rawCookies?
-					token = cookie.get('rc_token', rawCookies) if rawCookies?
-
-					if not uid?
-						uid = req.query.rc_uid
-						token = req.query.rc_token
-
-					unless uid and token and RocketChat.models.Users.findOneByIdAndLoginToken(uid, token)
-						res.writeHead 403
-						return false
-
-				res.setHeader 'content-disposition', "attachment; filename=\"#{ encodeURIComponent(file.name) }\""
-				return true
-
-	Meteor.startup ->
-		if Meteor.isServer
-			initFileStore()
-		else
-			Tracker.autorun (c) ->
-				if Meteor.userId() and RocketChat.settings.cachedCollection.ready.get()
-					initFileStore()
-					c.stop()
diff --git a/lib/fileUpload.js b/lib/fileUpload.js
new file mode 100644
index 00000000000..00cd4952289
--- /dev/null
+++ b/lib/fileUpload.js
@@ -0,0 +1,101 @@
+/* globals UploadFS, Cookies, FileUpload */
+
+if (UploadFS) {
+	RocketChat.models.Uploads.allow({
+		insert(userId/*, doc*/) {
+			return userId;
+		},
+
+		update(userId, doc) {
+			return userId === doc.userId;
+		},
+
+		remove(userId, doc) {
+			return userId === doc.userId;
+		}
+	});
+
+	const initFileStore = function() {
+		const cookie = new Cookies();
+		if (Meteor.isClient) {
+			document.cookie = 'rc_uid=' + escape(Meteor.userId()) + '; path=/';
+			document.cookie = 'rc_token=' + escape(Accounts._storedLoginToken()) + '; path=/';
+		}
+
+		Meteor.fileStore = new UploadFS.store.GridFS({
+			collection: RocketChat.models.Uploads.model,
+			name: 'rocketchat_uploads',
+			collectionName: 'rocketchat_uploads',
+			filter: new UploadFS.Filter({
+				onCheck: FileUpload.validateFileUpload
+			}),
+			transformWrite(readStream, writeStream, fileId, file) {
+				if (RocketChatFile.enabled === false || !/^image\/.+/.test(file.type)) {
+					return readStream.pipe(writeStream);
+				}
+
+				let stream = undefined;
+
+				const identify = function(err, data) {
+					if (err) {
+						return stream.pipe(writeStream);
+					}
+
+					file.identify = {
+						format: data.format,
+						size: data.size
+					};
+
+					if (data.Orientation && !['', 'Unknown', 'Undefined'].includes(data.Orientation)) {
+						RocketChatFile.gm(stream).autoOrient().stream().pipe(writeStream);
+					} else {
+						stream.pipe(writeStream);
+					}
+				};
+
+				stream = RocketChatFile.gm(readStream).identify(identify).stream();
+			},
+
+			onRead(fileId, file, req, res) {
+				if (RocketChat.settings.get('FileUpload_ProtectFiles')) {
+					let uid, token;
+
+					if (req && req.headers && req.headers.cookie) {
+						const rawCookies = req.headers.cookie;
+
+						if (rawCookies) {
+							uid = cookie.get('rc_uid', rawCookies) ;
+							token = cookie.get('rc_token', rawCookies);
+						}
+					}
+
+					if (!uid) {
+						uid = req.query.rc_uid;
+						token = req.query.rc_token;
+					}
+
+					if (!uid || !token || !RocketChat.models.Users.findOneByIdAndLoginToken(uid, token)) {
+						res.writeHead(403);
+						return false;
+					}
+				}
+
+				res.setHeader('content-disposition', `attachment; filename="${ encodeURIComponent(file.name) }"`);
+				return true;
+			}
+		});
+	};
+
+	Meteor.startup(function() {
+		if (Meteor.isServer) {
+			initFileStore();
+		} else {
+			Tracker.autorun(function(c) {
+				if (Meteor.userId() && RocketChat.settings.cachedCollection.ready.get()) {
+					initFileStore();
+					c.stop();
+				}
+			});
+		}
+	});
+}
diff --git a/lib/francocatena_fix.coffee b/lib/francocatena_fix.coffee
deleted file mode 100644
index a2ef678fb65..00000000000
--- a/lib/francocatena_fix.coffee
+++ /dev/null
@@ -1,2 +0,0 @@
-@i18n_status_func = (key,options) ->
-	return TAPi18n.__(key,options)
diff --git a/lib/francocatena_fix.js b/lib/francocatena_fix.js
new file mode 100644
index 00000000000..12125e91853
--- /dev/null
+++ b/lib/francocatena_fix.js
@@ -0,0 +1,3 @@
+this.i18n_status_func = function(key, options) {
+	return TAPi18n.__(key, options);
+};
diff --git a/lib/underscore.string.coffee b/lib/underscore.string.coffee
deleted file mode 100644
index f0845a77574..00000000000
--- a/lib/underscore.string.coffee
+++ /dev/null
@@ -1,15 +0,0 @@
-# This will add underscore.string methods to Underscore.js
-# except for include, contains, reverse and join that are 
-# dropped because they collide with the functions already 
-# defined by Underscore.js.
-
-mixin = (obj) ->
-	_.each _.functions(obj), (name) ->
-		if not _[name] and not _.prototype[name]?
-			func = _[name] = obj[name]
-			_.prototype[name] = ->
-				args = [this._wrapped]
-				push.apply(args, arguments)
-				return result.call(this, func.apply(_, args))
-
-mixin(s.exports())
\ No newline at end of file
diff --git a/lib/underscore.string.js b/lib/underscore.string.js
new file mode 100644
index 00000000000..f92095c585c
--- /dev/null
+++ b/lib/underscore.string.js
@@ -0,0 +1,16 @@
+/* globals mixin */
+
+// This will add underscore.string methods to Underscore.js
+// except for include, contains, reverse and join that are
+// dropped because they collide with the functions already
+// defined by Underscore.js.
+
+mixin = function(obj) {
+	_.each(_.functions(obj), function(name) {
+		if (!_[name] && !_.prototype[name]) {
+			_[name] = obj[name];
+		}
+	});
+};
+
+mixin(s.exports());