vercel/examples/aurelia/aurelia_project/tasks/test.js

import jest from 'jest-cli';
import path from 'path';
import packageJson from '../../package.json';

import { CLIOptions } from 'aurelia-cli';

export default cb => {
  let options = packageJson.jest;

  if (CLIOptions.hasFlag('watch')) {
    Object.assign(options, { watchAll: true });
  }

  process.env.BABEL_TARGET = 'node';

  jest
    .runCLI(options, [path.resolve(__dirname, '../../')])
    .then(({ results }) => {
      if (results.numFailedTests || results.numFailedTestSuites) {
        cb('Tests Failed');
      } else {
        cb();
      }
    });
};