import async from "async"; /** * Migration 10 * * Migration for changes in how the order of songs in a playlist is handled * @param {object} MigrationModule - the MigrationModule * @returns {Promise} - returns promise */ export default async function migrate(MigrationModule) { const playlistModel = await MigrationModule.runJob("GET_MODEL", { modelName: "playlist" }, this); return new Promise((resolve, reject) => { async.waterfall( [ next => { this.log("INFO", `Migration 10. Finding playlists with document version 3.`); playlistModel.find({ documentVersion: 3 }, (err, playlists) => { if (err) next(err); else { async.eachLimit( playlists.map(playlisti => playlisti._doc), 1, (playlisti, next) => { // sort playlists by the position property playlisti.songs.sort((song1, song2) => song1.position - song2.position); // delete the position property for each song playlisti.songs.forEach(song => delete song.position); // update the database playlistModel.updateOne( { _id: playlisti._id }, { $set: { songs: playlisti.songs, documentVersion: 4 } }, next ); }, err => { if (err) next(err); else { this.log("INFO", `Migration 10. Playlists found: ${playlists.length}.`); next(); } } ); } }); } ], err => { if (err) reject(new Error(err)); else resolve(); } ); }); }