cypress/system-tests/test/browser_path_spec.js

const path = require('path')
const { exec } = require('child_process')

const systemTests = require('../lib/system-tests').default
const launcher = require('@packages/launcher')

const absPath = (pathStr) => {
  return new Promise((resolve, reject) => {
    if (path.basename(pathStr) !== pathStr) {
      return resolve(pathStr)
    }

    return exec(`which ${pathStr}`, (err, stdout) => {
      if (err) {
        return reject(err)
      }

      return resolve(stdout.trim())
    })
  })
}

describe('e2e launching browsers by path', () => {
  systemTests.setup()

  it('fails with bad browser path', function () {
    return systemTests.exec(this, {
      project: 'e2e',
      spec: 'simple_spec.js',
      browser: '/this/aint/gonna/be/found',
      expectedExitCode: 1,
    })
    .then((res) => {
      expect(res.stdout).to.contain('We could not identify a known browser at the path you provided: `/this/aint/gonna/be/found`')

      expect(res.code).to.eq(1)
    })
  })

  it('works with an installed browser path', function () {
    return launcher.detect().then((browsers) => {
      return browsers.find((browser) => {
        return browser.family === 'chromium'
      })
    }).tap((browser) => {
      if (!browser) {
        throw new Error('A \'chromium\' family browser must be installed for this test')
      }
    }).get('path')
    // turn binary browser names ("google-chrome") into their absolute paths
    // so that server recognizes them as a path, not as a browser name
    .then((absPath))
    .then((foundPath) => {
      return systemTests.exec(this, {
        project: 'e2e',
        spec: 'simple_spec.js',
        browser: foundPath,
        snapshot: true,
      })
    })
  })
})