Mongolass

Elegant MongoDB driver for Node.js.

Installation

$ npm i mongolass --save

Usage

Just like mongoose:

'use strict';

const Mongolass = require('mongolass');
const mongolass = new Mongolass();
mongolass.connect('mongodb://localhost:27017/test');// const mongolass = new Mongolass('mongodb://localhost:27017/test');

const User = mongolass.model('User');

User
  .find()
  .select({ name: 1, age: 1 })
  .sort({ name: -1 })
  .exec()
  .then(console.log)
  .catch(console.error);

or use optional schema:

'use strict';

const Mongolass = require('mongolass');
const Schema = Mongolass.Schema;
const mongolass = new Mongolass('mongodb://localhost:27017/test');

const UserSchema = new Schema('UserSchema', {
  name: { type: 'string' },
  age: { type: 'number' }
});
const User = mongolass.model('User', UserSchema);

/*
equal to:
const User = mongolass.model('User', {
  name: { type: 'string' },
  age: { type: 'number' }
});
will create inner schema named `UserSchema`.
 */

User
  .insertOne({ name: 'nswbmw', age: 'wrong age' })
  .exec()
  .then(console.log)
  .catch(function (e) {
    console.error(e);
    console.error(e.stack);
  });
/*
{ [Error: ($.age: "wrong age") ✖ (type: number)]
  validator: 'type',
  actual: 'wrong age',
  expected: { type: 'number' },
  path: '$.age',
  schema: 'UserSchema',
  model: 'User',
  plugin: 'MongolassSchema',
  type: 'beforeInsertOne',
  args: [] }
Error
    at Model.insertOne (/Users/nswbmw/Desktop/mongolass-demo/node_modules/mongolass/lib/query.js:107:16)
    at Object.<anonymous> (/Users/nswbmw/Desktop/mongolass-demo/app.js:23:4)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Function.Module.runMain (module.js:441:10)
    at startup (node.js:139:18)
    at node.js:974:3
 */

ObjectId schema:

'use strict';

const Mongolass = require('mongolass');
const Schema = Mongolass.Schema;
const mongolass = new Mongolass('mongodb://localhost:27017/test');

const Post = mongolass.model('Post', {
  author: { type: Mongolass.Types.ObjectId }
});

Post.insertOne({ author: '111111111111111111111111' })
  .then(function () {
    return Post.find({ author: '111111111111111111111111' });
  })
  .then(console.log);
/*
[ { _id: 57caed24ecda6ffb15962591,
    author: 111111111111111111111111 } ]
 */

Mongolass vs Mongoose

知乎：从零开始写一个 Node.js 的 MongoDB 驱动库

---

I've been using Mongoose for years, it's great but complex sucks, so i wrote Mongolass. Mongolass is not simply mimicking Mongoose, but rather draw on the advantages of mongoose redesigned the architecture. Mongolass has some exciting features different from Mongoose:

1. Pure Schema. In Mongoose, Schema and Model and Entry are confused.

Schemas not only define the structure of your document and casting of properties, they also define document instance methods, static Model methods, compound indexes and document lifecycle hooks called middleware.

In Mongolass, Schema is only used for defining the structure of your document and casting of properties, Model used for retrievaling data from mongodb and register plugins, Entry(as result) is plain object. Schema is also optional.

2. Awesome Plugin System. Mongoose plugin system is not strong enough, eg: .pre, .post, then async next(). In Mongolass, we can register a plugin for Model or global mongolass instance. like:

User.plugin('xx', {
  beforeFind: function (...args) {},
  afterFind: function* (result, ...args) {// or function return Promise
    console.log(result, args);
    ...
  }
});

Above added two hook function for User, when User.find().xx().exec() is called, the execution order is as follows:

beforeFind(handle query args) -> retrieve data from mongodb -> afterFind(handle query result)

NOTE: Different order of calling plugins will output different results. The priority of Model's plugins is greater than global's. Mongolass's plugins could be substituted for Mongoose's (document instance methods + static Model methods + plugins).

3. Damn Detailed Error Information. see usage.

User
  .insertOne({ name: 'nswbmw', age: 'wrong age' })
  .exec()
  .then(console.log)
  .catch(function (e) {
    console.error(e);
    console.error(e.stack);
  });
/*
{ [Error: ($.age: "wrong age") ✖ (type: number)]
  validator: 'type',
  actual: 'wrong age',
  expected: { type: 'number' },
  path: '$.age',
  schema: 'UserSchema',
  model: 'User',
  plugin: 'MongolassSchema',
  type: 'beforeInsertOne',
  args: [] }
Error
    at Model.insertOne (/Users/nswbmw/Desktop/mongolass-demo/node_modules/mongolass/lib/query.js:107:16)
    at Object.<anonymous> (/Users/nswbmw/Desktop/mongolass-demo/app.js:23:4)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Function.Module.runMain (module.js:441:10)
    at startup (node.js:139:18)
    at node.js:974:3

According to the error instance, esay to know age expect a number but got a string, from error stack know it's broken on app.js:23:4 and the operator is Model.insertOne.

Schema

see another-json-schema.

Plugins

mongolass.plugin(pluginName, hooks);// register global plugin
User.plugin(pluginName, hooks);// register model plugin

example:

const co = require('co');
const moment = require('moment');
const Mongolass = require('mongolass');
const mongolass = new Mongolass('mongodb://localhost:27017/test');
const User = mongolass.model('User');

mongolass.plugin('addCreatedAt', {
  beforeInsert: function (format) {
    console.log('beforeInsert', this._op, this._args, format);
    // beforeInsert insert [ { firstname: 'san', lastname: 'zhang' } ] YYYY-MM-DD
    this._args[0].createdAt = moment().format(format);
  }
});

User.plugin('addFullname', {
  afterFindOne: function* (user, opt) {
    console.log('afterFindOne', this._op, this._args, opt);
    // afterFindOne findOne [] { sep: '-' }
    if (!user) return user;
    user.fullname = user.firstname + opt.sep + user.lastname;
    return user;
  },
  afterFind: async function (users, opt) {
    console.log('afterFind', this._op, this._args, opt);
    // afterFind find [ { firstname: 'san' } ] { sep: ' ' }
    if (!users.length) return users;
    return users.map(user => {
      user.fullname = user.firstname + opt.sep + user.lastname;
      return user;
    });
  }
});

co(function* () {
  yield User.insert({ firstname: 'san', lastname: 'zhang' }).addCreatedAt('YYYY-MM-DD');// when use yield, .exec() is omissible.
  console.log(yield User.findOne().addFullname({ sep: '-' }));
  // { _id: 5850186544c3b82d23a82e45,
  //   firstname: 'san',
  //   lastname: 'zhang',
  //   createdAt: '2016-12-13',
  //   fullname: 'san-zhang' }
  console.log(yield User.find({ firstname: 'san' }).addFullname({ sep: ' ' }));
  // [ { _id: 5850186544c3b82d23a82e45,
  //     firstname: 'san',
  //     lastname: 'zhang',
  //     createdAt: '2016-12-13',
  //     fullname: 'san zhang' } ]
}).catch(console.error.bind(console));

NOTE: Different order of calling plugins will output different results. The priority of Model's plugins is greater than global's.

example:

const co = require('co');
const Mongolass = require('mongolass');
const mongolass = new Mongolass('mongodb://localhost:27017/test');
const User = mongolass.model('User');

User.plugin('add2', {
  afterFindOne: function* (user) {
    if (!user) return user;
    user.name = `${user.name}2`;
    return user;
  }
});
User.plugin('add3', {
  afterFindOne: function* (user) {
    if (!user) return user;
    user.name = `${user.name}3`;
    return user;
  }
});

co(function* () {
  yield User.insert({ name: '1' });
  console.log(yield User.findOne().add2().add3());
  // { _id: 58501a8a7cc264af259ca691, name: '123' }
  console.log(yield User.findOne().add3().add2());
  // { _id: 58501a8a7cc264af259ca691, name: '132' }
}).catch(console.error.bind(console));

see mongolass-plugin-populate.

Built-in plugins

Mongolass has some built-in plugins, only for find and findOne.

• limit
• sort
• fields(alias: select)
• skip
• hint
• populate
• explain
• snapshot
• timeout
• tailable
• tailableRetryInterval
• numberOfRetries
• awaitdata
• oplogReplay
• exhaust
• batchSize
• returnKey
• maxScan
• min
• max
• showDiskLoc
• comment
• raw
• readPreference
• partial
• maxTimeMS

example:

const co = require('co');
const Mongolass = require('mongolass');
const mongolass = new Mongolass('mongodb://localhost:27017/test');
const User = mongolass.model('User');

co(function* () {
  yield User.insert({ name: '1' });
  yield User.insert({ name: '2' });
  const result = yield User
    .find()
    .skip(1)
    .limit(1);
  console.log(result);
  // [ { _id: 58501c1281ea915a2760a2ee, name: '2' } ]
}).catch(console.error.bind(console));

Test

$ npm test (coverage 100%)

License

MIT