Strapi v4 Testing: setup and tearDown in TypeScript

strapi.ts

// Taken from https://codesandbox.io/s/wg9317
// Thanks, you helped me a lot! https://github.com/haysclark

import strapi, { Strapi } from "@strapi/strapi";
import { compile } from "@strapi/typescript-utils";
import * as fs from "fs";

let instance: Strapi;

export const setupStrapi = async (): Promise<Strapi> => {
  if (!instance) {
    await compile("");

    instance = await strapi({ distDir: "./dist" }).load();

    const { app } = instance.server;
    app
      .use(instance.server.router.routes())
      .use(instance.server.router.allowedMethods());
  }
  jest.setTimeout(60000);
  return instance;
};

export async function tearDownStrapi(strapi: Strapi) {
  const dbSettings = strapi.config.get("database");

  await strapi.destroy();
  instance = undefined;

  // delete test database after all tests
  if (dbSettings && dbSettings.filename) {
    const tmpDbFile = `${__dirname}/../${dbSettings.filename}`;
    if (fs.existsSync(tmpDbFile)) {
      fs.unlinkSync(tmpDbFile);
    }
  }
}