Q: Why do people use mongoose?

Here are some of the benefits:

• You can execute commands right away without having to wait for mongo.connect()
• You get schema validation
• You can create synthetic joins via populate

However, there are some potential downsides:

• Mongoose is global object - causing potential conflicts
• Mongoose can be very slow with all the getters, setters and whatnot
• the lean() options ends up being slower than native
• It can be difficult to understand what is going on behind the scenes
• The schema is non-standard

Moongoose to the rescue

• Just over 100 LOC - simple wrapper around native
• No need to wait for connection before executing commands
• Efficient populate for streaming and findOnes
• Validation with JSON schema
• Acts global but can be cloned for ringfencing different instances

Examples

Example: fetching data

var moongoose = require('moongoose');

moongoose.connect('mongodb://localhost:27017/test');

// Find one record and populate
moongoose.collection('test')
  .findOne({})
  .populate('org_id','orgs')
  .then(console.log);

// Find all record, populate and stream
moongoose.collection('test')
  .find()
  .populate('org_id','orgs')
  .stream()
  .pipe(...);

// Find all records, poopulate and capture into array
moongoose.collection('test')
  .find()
  .populate('org_id','orgs')
  .toArray()
  .then(console.log)

Example: save a record with validation

var test = moongoose.collection('test',{
  schema: {
    additionalProperties: false,
    properties: {
      answer: {type:'boolean'},
      fail: {type:'boolean'}
    }
  },
  validate : function(data) {
    if (data.fail)
      throw 'Failed custom validation';
  }
});

// This successfully save the record - junk is removed in validation
test.save({
  answer: true,
  junk: 'this gets removed'
})
.then(d => console.log(d.ops[0]),console.log);

// This fails validation and is not saved
test.save({
  answer: 'not a boolean'
})
.then(d => console.log(d.ops[0]),console.log);

// This passes json-schema validation but fails custom validation
test.save({
  answer: true,
  fail: true
})
.then(d => console.log(d.ops[0]),console.log);