Question

I’m messing around with Mongoose, and I’m noticing that my find callback is being called multiple times when saving an invalid item:

persist.js

mongoose.model('ContentTag', new mongoose.Schema({
    content:   requiredString,
    tag:       requiredString
}));

test.js (using mocha)

describe('content tag', function() {
    it('should not save an empty content tag', function(done) {
        persist.ContentTag().save(function(err) {
            assert.ok(err);

            persist.ContentTag.find(function(err, items) {
                assert.equal(0, items.length);
                done();
            });
        });
    });

This produces the following error output:

Save err: ValidatorError: Validator "required" failed for path tag
Save err: ValidatorError: Validator "required" failed for path content
Find err: null
Find err: null

And the following error:

 1) Persist content tag should not save an empty content tag:
     Error: done() called multiple times
      at multiple (/usr/local/lib/node_modules/mocha/lib/runnable.js:168:31)
      at done (/usr/local/lib/node_modules/mocha/lib/runnable.js:174:26)
      at Runnable.run.duration (/usr/local/lib/node_modules/mocha/lib/runnable.js:190:9)
      at persist.ContentTag.content (path/test/server-test.js:21:21)
      at Query.execFind (path/node_modules/mongoose/lib/mongoose/query.js:572:26)
      at Cursor.toArray (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:122:15)
      at Cursor.each (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:167:11)
      at Cursor.nextObject (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:467:28)
      at Cursor.close (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:625:17)
      at Cursor.nextObject (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:467:10)
      at Cursor.nextObject.commandHandler (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/cursor.js:452:15)
      at EventEmitter.emit (events.js:96:17)
      at Db.open.self.serverConfig.connection.addListener.self.state (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/db.js:90:12)
      at EventEmitter.emit (events.js:93:17)
      at Connection.open.receiveListener (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/connection.js:82:16)
      at Socket.Connection.open.receiveListener (path/node_modules/mongoose/support/node-mongodb-native/lib/mongodb/connection.js:85:16)
      at Socket.EventEmitter.emit (events.js:93:17)
      at TCP.onread (net.js:391:31)

It looks like when there are multiple validation errors, the save callback is called once for each error.

When I remove the new keyword, I get the following error:

 1) Persist content tag should not save an empty content tag:
     TypeError: Object #<Object> has no method 'buildDoc'
      at Object.Document (../node_modules/mongoose/lib/mongoose/document.js:26:19)
      at Object.Model (../node_modules/mongoose/lib/mongoose/model.js:24:12)
      at Object.model [as ContentTag]

Answer 1

The callback to save is called once for each validation err. Thus, I was calling done() multiple times. In retrospect, there’s no point to asserting both that err is defined and that a find() call comes up empty.