A collection of utilities to help with unit-testing Sequelize models and code that needs those models. This project uses jest and it's a fork of this project Thanks to Dave Give him some love.

Prerequisites

This library assumes:

1. You are using jest

Installation

Add sequelize-jest-helpers as a devDependency:

npm i -D sequelize-test-helpers

Examples

Unit testing models created with sequelize.define

Note: See below for how to test models created using Model.init

Let's say you have a Sequelize model User as follows:

src/models/User.js

const model = (sequelize, DataTypes) => {
  const User = sequelize.define(
    'User',
    {
      age: {
        type: DataTypes.INTEGER.UNSIGNED
      },
      firstname: {
        type: DataTypes.STRING,
        allowNull: false,
        validate: {
          notEmpty: true
        }
      },
      lastname: {
        type: DataTypes.STRING,
        allowNull: false,
        validate: {
          notEmpty: true
        }
      },
      email: {
        type: DataTypes.STRING,
        allowNull: false,
        unique: true,
        lowercase: true,
        validate: {
          isEmail: true,
          notEmpty: true
        }
      },
      token: {
        type: DataTypes.STRING,
        validate: {
          notEmpty: true
        }
      }
    },
    {
      indexes: [
        { unique: true, fields: ['email'] },
        { unique: true, fields: ['token'] }
      ]
    }
  )

  User.associate = ({ Company }) => {
    User.belongsTo(Company)
  }

  return User
}

module.exports = model

You can use sequelize-test-helpers to unit-test this with mocha as follows:

test/unit/models/User.spec.js

const { expect } = require('chai')

const {
  sequelize,
  dataTypes,
  checkModelName,
  checkUniqueIndex,
  checkPropertyExists
} = require('sequelize-test-helpers')

const UserModel = require('../../src/models/User')

describe('src/models/User', () => {
  const User = UserModel(sequelize, dataTypes)
  const user = new User()

  checkModelName(User)('User')

  context('properties', () => {
    ;['age', 'firstname', 'lastname', 'email', 'token'].forEach(checkPropertyExists(user))
  })

  context('associations', () => {
    const Company = 'some dummy company'

    before(() => {
      User.associate({ Company })
    })

    it('defined a belongsTo association with Company', () => {
      expect(User.belongsTo).to.have.been.calledWith(Company)
    })
  })

  context('indexes', () => {
    ;['email', 'token'].forEach(checkUniqueIndex(user))
  })
})

Built-in checks

| Check | What it does | | -------------------------- | -------------------------------------------------------- | | checkHookDefined | Checks that a particular hook is defined. | | checkModelName | Checks that the model is named correctly. | | checkNonUniqueIndex | Checks that a specific non-unique index is defined. | | checkPropertyExists | Checks that the model has defined the given property. | | checkUniqueCompoundIndex | Checks that a specific unique compound index is defined. | | checkUniqueIndex | Checks that a specific unique index is defined. |

Checking associations

The various association functions are stubbed so you can simply invoke the the model's associate function in a before block then use sinon's standard expectation syntax to check they were called with the correct values.

hasOne

it("defined a hasOne association with Image as 'profilePic'", () => {
  expect(User.hasOne).to.have.been.calledWith(Image, {
    as: 'profilePic'
  })
})

belongsTo

it('defined a belongsTo association with Company', () => {
  expect(User.belongsTo).to.have.been.calledWith(Company)
})

hasMany

it("defined a hasMany association with User as 'employees'", () => {
  expect(Company.hasMany).to.have.been.calledWith(User, {
    as: 'employees'
  })
})

belongsToMany

it("defined a belongsToMany association with Category through CategoriesCompanies as 'categories'", () => {
  expect(Company.belongsToMany).to.have.been.calledWith(Category, {
    through: CategoriesCompanies,
    as: 'categories'
  })
})

Unit testing code that requires models

Let's say you have a utility function that takes some data and uses it to update a user record. If the user does not exist it returns null. (Yes I know this is a contrived example)

src/utils/save.js

const { User } = require('../models')

const save = async ({ id, ...data }) => {
  const user = await User.findOne({ where: { id } })
  if (user) return await user.update(data)
  return null
}

module.exports = save

As a convenience, makeMockModels will automatically populate your mockModels with mocks of all of the models defined in your src/models folder (or if you have a .sequelizerc file it will look for the model-path in that). Simply override any of the specific models you need to do stuff with.

Testing models created with Model.init

Sequelize also allows you to create models by extending Sequelize.Model and invoking its static init function as follows:

Note: creating your models this way makes it harder to test their use.

const { Model, DataTypes } = require('sequelize')

const factory = sequelize => {
  class User extends Model {}
  User.init(
    {
      firstName: DataTypes.STRING,
      lastName: DataTypes.STRING
    },
    { sequelize, modelName: 'User' }
  )
  return User
}

module.exports = factory

Listing your models

Assuming your src/models/index.js (or your equivalent) exports all your models, it's useful to be able to generate a list of their names.

const { listModels } = require('sequelize-test-helpers')

console.log(listModels()) // will spit out a list of your model names.

Similarly to makeMockModels above, listModels will find all of the models defined in your src/models folder (or if you have a .sequelizerc file it will look for the model-path in that).

Custom models paths and custom file suffixes

By default makeMockModels and listModels will both look for your models in files ending with .js in either the models path defined in .sequelizerc, or in src/models. If however your models are not .js files and the models folder is somewhere else you can pass in a custom models folder path and a custom suffix.

• listModels(customModelsFolder, customSuffix)

  const modelNames = listModels('models', '.ts')

• makeMockModels(yourCustomModels, customModelsFolder, customSuffix)

  const models = makeMockModels({ User: { findOne: stub() } }, 'models', '.ts')

Development

Branches

| Branch | Status | Coverage | Audit | Notes | | ------ | ------ | -------- | ----- | ----- | | master | | | | Latest stable release |

Prerequisites

• NodeJS. I use nvm to manage Node versions — brew install nvm.

Initialisation

npm install

Test it

• npm test — runs the unit tests
• npm run test:unit:cov — runs the unit tests with code coverage

Lint it

npm run lint

Contributing

Please see the contributing notes.

Thanks

• Thanks to reallinfo for the logo.