joi-services

Service objects supported by joi validation.

Service objects is the place for all of your business logic.

Installation

npm install joi

Usage

const JoiService = require('joi-services');

class InviteUserService extends JoiService {
  // data required to run the process function
  static schema = Joi.object({
    name: Joi.string().required(),
    email: Joi.string().email().required(),
  })

  // encapsulate business rules in the process function
  async process() {

    // create user with the isActive flag set as false
    const user = await User.create({
      email: this.cleanedData.email,
      name: this.cleanedData.name,
      isActive: false
    })

    // send email
    await Mailer.send(user.email)
  }
}

await InviteUser.execute({
  name: 'Ken Masters',
  email: '[email protected]'
})

Validation

The InviteUserService will throw a validation error if the .execute function is missing one of the required variables when invoked.

Validating Sequelize instances with joi extensions

JoiService provides an extended version of joi support for validating a sequelize instance. You just have to use the Joi module provided by JoiService using JoiService.Joi

const JoiService = require('joi-services');

class AcceptInviteService extends JoiService {
  // data required to run the process function
  static schema = JoiService.Joi.object({
    user: Joi.sequelize().instance(User).required(),
  })

  // encapsulate business rules in the process function
  async process() {

    // create user with the isActive flag set as false
    this.cleanedData.user.isActive = true
  }
}

const user = await User.findOne({ where: { email: '[email protected]' } })
await AcceptInviteService.execute({
  user
})

LifeCycle Hooks

JoiService.preProcess() -> Object

Runs before the .process function is invoked and passes the object returned to the process.

JoiService.process(options)

• options The options returned by the preprocess handler

JoiService.postProcess(options)

After the process gets executed, the options generated in the preProcess function are passed to the postProcess handler alongside with any errors that occurred during the process invokation.

• options The options returned by the preprocess handler
• [options.err] Defined if an error occurred during processing

class SequelizeService extends JoiService {
  async preProcess() {
    const transaction = await sequelize.transaction();
    return { transaction };
  }

  async postProcess({ transaction, err }) {
    if (err) {
      // rollback transaction
      await transaction.rollback();
      return;
    }

    await transaction.commit();
  }
}

class CreateUserService extends SequelizeService {
  async process({ transaction }) {
    User.create({
      name: 'Ryu'
    }, { transaction })
  }
}

JoiService.Joi.sequelize

Generates a sequelize schema object.

JoiService.Joi.sequelize.instance

The sequelize class you'll be validating it's an instance of

JoiService.Joi.sequelize.isnew

You can test whether you accept new instances or not.

// we only accept users already in the database
JoiService.Joi.sequelize().instance(User).isnew(false)