sequelize auto migration generator

sequelize-migration-generator.js

const models = require('../app/models')
const Sequelize = require('sequelize')
const fs = require('fs')
const path = require('path')

const sequelize = new Sequelize('', '', '', {
  host: '',
  dialect: 'postgres'
})

for (let model in models) {
  let attributes = models[model].rawAttributes

  for (let column in attributes) {
    delete attributes[column].Model
    delete attributes[column].fieldName
    delete attributes[column].field
    for (let property in attributes[column]) {
      if (property.startsWith('_')) {
        delete attributes[column][property]
      }
    }

    if (typeof attributes[column]['type'] !== 'undefined') {
      if (
        typeof attributes[column]['type']['options'] !== 'undefined' &&
        typeof attributes[column]['type']['options'].toString === 'function'
      ) {
        attributes[column]['type']['options'] = attributes[column]['type'][
          'options'
        ].toString(sequelize)
      }

      if (typeof attributes[column]['type'].toString === 'function') {
        attributes[column]['type'] = attributes[column]['type'].toString(
          sequelize
        )
      }
    }
  }

  let schema = JSON.stringify(attributes, null, 4)
  let tableName = models[model].tableName
  let indexes = ['\n']

  if (models[model].options.indexes) {
    models[model].options.indexes.forEach(obj => {
      indexes.push('        .then(() => {')
      indexes.push('            return queryInterface.addIndex(')
      indexes.push(`                '${tableName}',`)
      indexes.push(`                ['${obj.fields.join("','")}']`)

      let opts = {}
      if (obj.name) {
        opts.indexName = obj.name
      }
      if (obj.unique === true) {
        opts.indicesType = 'UNIQUE'
      }
      if (obj.method === true) {
        opts.indexType = obj.method
      }
      if (Object.keys(opts).length) {
        indexes.push(`                , ${JSON.stringify(opts)}`)
      }

      indexes.push('            )')
      indexes.push('        })')
    })
  }
  if (schema) {
    schema = schema
      .split(/\r\n|\r|\n/)
      .map(line => '            ' + line)
      .join('\n')

    let template = `'use strict';
module.exports = {
    up: function(queryInterface, Sequelize) {
            return queryInterface.createTable('${tableName}',
${schema})
       ${indexes.join('\n')}
    },
    down: function(queryInterface, Sequelize) {
            return queryInterface.dropTable('${tableName}');
    }
};`

    let d = new Date()

    let filename =
      [
        d.getFullYear(),
        d.getMonth() + 1,
        d.getDate(),
        d.getHours(),
        d.getMinutes(),
        d.getSeconds()
      ]
        .map(num => (num <= 60 && (num + 100).toString().substring(1)) || num)
        .join('') + `-${models[model].tableName}`

    fs.writeFileSync(
      path.resolve(
        __dirname,
        '..',
        'database',
        'migrations',
        `./${filename}.js`
      ),
      template
    )
  }
}