Jest + Node.js + Postgres testing pipeline

01-minimal-seed.ts

import { Knex } from "knex"

export async function seed(knex: Knex): Promise<void> {
  // Delete order is specific because of foreign key references
  await knex.delete().from("...")

  await knex("users").insert(TestUsers)
  ...

  await knex.raw("refresh materialized view ...")
}

setup.ts

import knex, { Knex } from "knex"
import shell from "shelljs"
import * as knexConfig from "../../knexfile"

declare global {
  var __KNEX__: Knex
}

// In a GitHub action, process.env.CI will be true, and a Postgres instance will
// already be running.  See .github/workflows/test.yml.
//
// Locally, use Docker to start a Postgres + PostGIS server. (It stays running
// after tests end -- maybe we want to change this.)

export default async function () {
  let pgContainerName = ""

  if (!process.env.CI) {
    if (!shell.which("docker"))
      throw new Error("Docker is required outside of the CI environment")
    if (shell.exec("docker ps", { silent: true }).code !== 0)
      throw new Error("Docker is installed but `docker ps` returned an error")

    // Try to use and run an existing container since startup time is so slow.
    pgContainerName = "test-postgres"
    const inspect = shell.exec(`docker inspect ${pgContainerName}`, {
      silent: true,
    })
    if (inspect.code === 0) {
      const obj = JSON.parse(inspect)
      if (!obj[0]?.State.Running) {
        console.log(`Starting Docker container ${pgContainerName}`)
        shell.exec(`docker start ${pgContainerName}`)
      }
    } else {
      const cmd = [
        "docker run",
        `--name ${pgContainerName} -e POSTGRES_PASSWORD=sekrit -p 5499:5432 -d`,
        /arm64\s*$/.test(shell.exec("uname -a"))
          ? "--platform linux/amd64/v8"
          : "",
        "postgis/postgis:13-3.3",
        "-c fsync=off",
      ].join(" ")
      console.log(`Starting Docker container with: ${cmd}`)
      shell.exec(cmd)
    }
  }

  const db = knex(knexConfig)
  globalThis.__KNEX__ = db

  // Try connecting. It takes a few tries.
  let tries = 0
  while (true) {
    try {
      await db.select(1)
      break
    } catch (err) {
      console.log(`Connecting to Postgres failed: ${err}`)
      if (tries >= 40) {
        if (!process.env.CI) {
          console.log("------------- DOCKER POSTGRES LOG --------------")
          shell.exec(`docker logs ${pgContainerName}`)
          console.log("------------------------------------------------")
        }
        throw new Error("Failed to connect to Postgres")
      } else {
        tries++
        await new Promise((resolve) => setTimeout(resolve, 500))
      }
    }
  }

  // Run migrations and seed data
  await db.migrate.latest()
  await db.seed.run()
}

teardown.ts

export default async function () {
  globalThis.__KNEX__.destroy()
}

test.yml

name: Tests

on: [push]

concurrency:
  group: build-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: true

jobs:
  run-tests:
    runs-on: ubuntu-latest

    services:
      # https://docs.github.com/en/actions/using-containerized-services/creating-postgresql-service-containers
      postgres:
        image: "postgis/postgis:13-3.3-alpine"
        env:
          POSTGRES_PASSWORD: sekrit
        ports:
          - 5499:5432
        options: >-
          --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5

    steps:
      - uses: actions/checkout@v3
      - uses: actions/setup-node@v3
        with:
          node-version: "16"
          cache: "yarn"
      - run: yarn install --frozen-lockfile
      - run: yarn test:ci
        env:
          DATABASE_URL: "postgresql://postgres:sekrit@postgres:5432"

      - name: Tests OK
        if: ${{ success() }}
        run: |
          curl --request POST \
          --url https://api.github.com/repos/${{ github.repository }}/statuses/${{ github.sha }} \
          --header 'authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' \
          --header 'content-type: application/json' \
          --data '{
            "context": "tests",
            "state": "success",
            "description": "Tests passed",
            "target_url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}"
          }'

      - name: Tests Failed
        if: ${{ failure() }}
        run: |
          curl --request POST \
          --url https://api.github.com/repos/${{ github.repository }}/statuses/${{ github.sha }} \
          --header 'authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' \
          --header 'content-type: application/json' \
          --data '{
            "context": "tests",
            "state": "failure",
            "description": "Tests failed",
            "target_url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}"
          }'

things.test.ts

jest.mock("lib/sendgrid")
jest.mock("lib/twilio")

const emailFn = jest.mocked(sendEmail)
const smsFn = jest.mocked(sendSMS)

describe("Things", () => {
  beforeEach(async () => {
    await db.seed.run({ specific: "minimal.ts" })
    jest.useRealTimers()
    emailFn.mockReset()
    smsFn.mockReset()
  })

  it("tests a thing", async () => {
    ...