How to register mongoose plugin for all schemas?

Question

What am I missing? The Mongoose docs say that mongoose.plugin() registers a plugin for all schemas. This is not working. I CAN register my plugin on EACH schema.

My plugin:

module.exports = function (schema, options) {

    schema.set('toObject',{
        transform: function (doc, ret, options) {
            return {
                test: 'It worked!'
            };
        }
    });
};

My schema:

var testPlugin = require('test-plugin.js');

var personSchema = mongoose.Schema({

    _id : { type: String, default: $.uuid.init },

    ssn : { type: String, required: true, trim: true },

    first : { type: String, required: true, trim: true },
    middle : { type: String, required: true, trim: true },
    last : { type: String, required: true, trim: true }
});
personSchema.plugin(testPlugin);

var model = mongoose.model('Person', personSchema);

module.exports = model;

The code above works, unfortunately. However, the following code does not:

var personSchema = mongoose.Schema({

    _id : { type: String, default: $.uuid.init },

    ssn : { type: String, required: true, trim: true },

    first : { type: String, required: true, trim: true },
    middle : { type: String, required: true, trim: true },
    last : { type: String, required: true, trim: true }
});

var model = mongoose.model('Person', personSchema);

module.exports = model;

My test app:

var testPlugin = require('test-plugin.js');
mongoose.plugin(testPlugin);

mongoose.Promise = global.Promise;
mongoose.connect(config.db);
mongoose.connection.on('error', function (err) {
    if (err) { throw err; }
});
mongoose.connection.once('open', function (err) {
    if (err) { throw err; }

    seeds.doSeed(function(err){
        if (err) { return process.exit(1); }

        models.Person.find({}, function(err, people){
            if (err) { throw err; }

            var person = people[0];
            var oPerson = person.toObject();

            console.log(JSON.stringify(oPerson));
        });
    });
});

I've tried moving the mongoose.plugin(testPlugin) all over the app.js file... after the connect, etc... and nothing has worked.

Answer 1

Plugins might not be registered with mongoose.plugin(myMongoosePlugin) because mongoose models were created before you are registering plugins globally.

• In case if you have expressjs routes:

Make sure that in your app.js (server.js) you are registering mongoose plugins before you are registering/creating expressjs routes (which are using mongoose models to communicate with database).

Example:

in app.js

const express = require(express);
const mongoose = require('mongoose');
const myMongoosePlugin = require('<Mongoose Plugin file path>');

mongoose.plugin(myMongoosePlugin);

let app = express();

//register expressjs routes
require('<Express routes file path>')(app, express.Router());

// or create expressjs routes
app.post('/person', (req, res, next) => {
    //where someMethod is using person mongoose model
    this.someController.someMethod(someArguments)
        .then((user) => {
            res.json(user);
        }).catch((error) => {
            next(error);
        });
});

// ... Some other code ...
mongoose.connect(<databaseConnectionString>);
app.listen(<Port>);

Answer 2

Try requiring your model also in your app.js file. Somewhere after mongoose.plugin(testPlugin).