Automattic/mongoose · error · MongooseError

Connection.prototype.dropDatabase() no longer accepts a call

Error message

Connection.prototype.dropDatabase() no longer accepts a callback

What it means

Mongoose 7 removed callback support; dropDatabase() is async and returns a Promise that resolves after the entire database (collections, documents, indexes) is deleted. Because the method takes no options, a function as the FIRST argument is treated as a removed callback and the method rejects immediately (lib/connection.js:939). Models stay compiled — only the data is dropped.

Source

Thrown at lib/connection.js:939

/**
 * Helper for `dropDatabase()`. Deletes the given database, including all
 * collections, documents, and indexes.
 *
 * #### Example:
 *
 *     const conn = mongoose.createConnection('mongodb://127.0.0.1:27017/mydb');
 *     // Deletes the entire 'mydb' database
 *     await conn.dropDatabase();
 *
 * @method dropDatabase
 * @return {Promise}
 * @api public
 */

Connection.prototype.dropDatabase = async function dropDatabase() {
  if (arguments.length >= 1 && typeof arguments[0] === 'function') {
    throw new MongooseError('Connection.prototype.dropDatabase() no longer accepts a callback');
  }

  await this._waitForConnect();

  // If `dropDatabase()` is called, this model's collection will not be
  // init-ed. It is sufficiently common to call `dropDatabase()` after
  // `mongoose.connect()` but before creating models that we want to
  // support this. See gh-6796
  for (const model of Object.values(this.models)) {
    delete model.$init;
  }

  return this.db.dropDatabase();
};

/*!
 * ignore
 */

View on GitHub (pinned to 49cdab0136)

Solutions

Remove the callback and await: await conn.dropDatabase()
In test hooks: beforeEach(async () => { await conn.dropDatabase(); })

Example fix

// before
conn.dropDatabase((err) => { done(err); });

// after
await conn.dropDatabase();

Defensive patterns

Strategy: validation

Validate before calling

function dropDatabaseSafe(...args) {
  if (args.some(a => typeof a === 'function')) {
    throw new TypeError('dropDatabase takes no callback — await the promise');
  }
  return conn.dropDatabase();
}

Prevention

Rewrite test reset hooks as async beforeEach/afterEach with await
Run a repo-wide search for `, (err` and `(err =>` near lifecycle calls when upgrading
Prefer deleteMany({}) or dropCollection over dropDatabase where possible to limit blast radius

When it happens

Trigger: conn.dropDatabase((err) => { ... }) — a function as the only argument.

Common situations: Test-suite reset helpers (beforeEach/beforeAll) written against mongoose 6 or earlier; upgrading to mongoose 7/8/9 without rewriting teardown code.

Related errors

AI-assisted analysis of Automattic/mongoose@49cdab0136 (2026-08-21). Data as JSON: /api/errors/e73577516a844701. Report an issue: GitHub.