Knex & TypeScript

...README.md

Goals

• Make all parts of Knex TypeScript-safe

db.ts

import * as Knex from 'knex'
import { log } from './logging'

export const config = {
  client: 'pg',
  connection: {
    host: process.env.POSTGRES_HOST
    user: process.env.POSTGRES_USER,
    password: process.env.POSTGRES_PASSWORD,
    database: process.env.POSTGRES_DB
  },
  migrations: {
    // This is missing from the TypeScript types currently.
    stub: 'migration.stub'
  }
}

const instance: Knex = Knex(config as Knex.Config)

log.info(
  `Will connect to postgres://${config.connection.user}@${
    config.connection.host
  }/${config.connection.database}`
)
instance
  .raw('select 1')
  .then(() => {
    log.info(`Connected to database - OK`)
  })
  .catch(err => {
    log.error(`Failed to connect to database: ${err}`)
    process.exit(1)
  })

export const db = () => instance

// Returns a timestamp suitable for inserting into Postgres
export const timestamp = (): string => new Date().toUTCString()

knexfile.ts

import { config } from './db'

module.exports = config

migration.stub

import * as Knex from 'knex'

exports.up = (knex: Knex) => knex.schema

exports.down = (knex: Knex) => knex.schema

package.json

{
  ...
  "scripts": {
    "db:migrate": "knex migrate:latest",
    "db:rollback": "knex migrate:rollback",
    "db:createMigration": "knex migrate:make"
  },
  "dependencies": {
    "knex": "^0.15.2",
    "pg": "^7.5.0",
  },
  "devDependencies": {
    "@types/knex": "^0.14.26",
  }
}

tsconfig.json

// Optional - Mostly provided here for reference
{
  "compilerOptions": {
    "target": "esnext",
    "module": "commonjs",
    "jsx": "react",
    "strict": true,
    "resolveJsonModule": true
  },
  "exclude": ["node_modules"]
}