next.js/test/development/app-hmr/hmr-env.test.ts

import { FileRef, nextTestSetup } from 'e2e-utils'
import { retry } from 'next-test-utils'
import path from 'path'

const envFile = '.env.development.local'

describe(`app-dir hmr-env`, () => {
  const { next } = nextTestSetup({
    files: new FileRef(path.join(__dirname, 'fixtures', 'default-template')),
    patchFileDelay: 1000,
  })

  it.each(['node', 'node-module-var', 'edge', 'edge-module-var'])(
    'should update server components pages when env files is changed (%s)',
    async (page) => {
      const browser = await next.browser(`/env/${page}`)
      expect(await browser.elementByCss('p').text()).toBe('mac')

      await next.patchFile(envFile, 'MY_DEVICE="ipad"', async () => {
        let logs

        await retry(async () => {
          logs = await browser.log()
          expect(logs).toEqual(
            expect.arrayContaining([
              expect.objectContaining({
                message: expect.stringContaining('[Fast Refresh] done'),
                source: 'log',
              }),
            ])
          )
        })

        await retry(async () => {
          expect(await browser.elementByCss('p').text()).toBe('ipad')
        })

        expect(logs).toEqual(
          expect.arrayContaining([
            expect.objectContaining({
              message: expect.stringContaining('[Fast Refresh] done in'),
              source: 'log',
            }),
          ])
        )
      })

      // ensure it's restored back to "mac" before the next test
      await retry(async () => {
        expect(await browser.elementByCss('p').text()).toBe('mac')
      })

      expect(next.cliOutput).not.toContain('FATAL')
    }
  )
})