Justmodel NPM | npm.io

justmodel

Extendable immutable javascript models with validation and change tracking

Description

JustModel is a modern extendable model library written in typescript, that provides several features that every model library should have:

Static typed data types

Justmodel has fully typed models when working with typescript and flowtype, that provide type safety when working with models.

import { Model } from 'justmodel';

type User = {
  username: string;
  password: string;
}; 

class UserModel extends Model<User> {}

const user = new UserModel().create({username: 'username'}) // <-- property password is missing in type

Immutable and non-immutable operations

All operations are immutable by default, except is in place mutation methods are used

let mutatedUser = user.update({password: 'newpassword'});

user === mutatedUser // <-- false as immutable operation was used

muetatedUser = user.updateInPlace({password: 'newpassword'});

user === mutatedUser // <-- true as model was mutated in place

Data validation with create, update and load joi schemas

class UserModel extends Model<User> {
  get schema() {
    return Joi.object({
      username: Joi.string(),
      password: Joi.string().required(),
      hashedPassword: Joi.string().hex()
    }).xor('password', 'hashedPassword');
  }

  get createSchema() {
    return this.schema.requiredKeys(['password']);
  }
}

const user = new UserModel().create({
  username: 'user'
}); // <-- validation error as password is missing

Change detection

Just model tracks changes on models and provides method that gets old value or tells if change was made compared to initial value. This is very usefull if doing update oprations on model and need to know if values have changed.

const model = new UserModel().load(data);

model.updateInPlace(req.data);

if (model.hasChanged('password')) {
  // check old password for example
}

Insallation

npm install --save justmodel

Example

import { Model } from 'justmodel';

class UserModel extends Model<User> {
  get schema() {
    return Joi.object({
      username: Joi.string().min(4).max(20).lowercase(),
      password: Joi.string().required().min(8),
      email: Joi.string().email().required(),
      hashedPassword: Joi.string().hex()
    });
  }

  get createSchema() {
    return this.schema.requiredKeys(['password']);
  }

  value() {
    return this._data.delete('password').toJS();
  }
}

const user = new UserModel().create({
  username: 'user',
  password: 'mypassword',
  email: 'email@example.com'
});

checkWeakPasswords(user);

user.updateInPlace({
  hashedPassword: hashPassword(user.password)
});

if(user.hasChanged('email')) {
  return sendChangeEmail(user);
}

save(user);

Development

npm t: Run test suite
npm start: Runs npm run build in watch mode
npm run test:watch: Run test suite in interactive watch mode
npm run test:prod: Run linting and generate coverage
npm run build: Generage bundles and typings, create docs
npm run lint: Lints code
npm run commit: Commit using conventional commit style (husky will tell you to use it if you haven't :wink:)