Rocket.Chat/app/custom-sounds/server/methods/uploadCustomSound.js

import { Meteor } from 'meteor/meteor';

import { hasPermission } from '../../../authorization';
import { Notifications } from '../../../notifications';
import { RocketChatFile } from '../../../file';
import { RocketChatFileCustomSoundsInstance } from '../startup/custom-sounds';

Meteor.methods({
	uploadCustomSound(binaryContent, contentType, soundData) {
		if (!hasPermission(this.userId, 'manage-sounds')) {
			throw new Meteor.Error('not_authorized');
		}

		const file = Buffer.from(binaryContent, 'binary');

		const rs = RocketChatFile.bufferToStream(file);
		RocketChatFileCustomSoundsInstance.deleteFile(`${soundData._id}.${soundData.extension}`);
		const ws = RocketChatFileCustomSoundsInstance.createWriteStream(`${soundData._id}.${soundData.extension}`, contentType);
		ws.on(
			'end',
			Meteor.bindEnvironment(() => Meteor.setTimeout(() => Notifications.notifyAll('updateCustomSound', { soundData }), 500)),
		);

		rs.pipe(ws);
	},
});