rsnext/test/e2e/app-dir/rsc-external.test.ts

import path from 'path'
import { renderViaHTTP, fetchViaHTTP } from 'next-test-utils'
import { createNext, FileRef } from 'e2e-utils'
import { NextInstance } from 'test/lib/next-modes/base'

async function resolveStreamResponse(response: any, onData?: any) {
  let result = ''
  onData = onData || (() => {})
  await new Promise((resolve) => {
    response.body.on('data', (chunk) => {
      result += chunk.toString()
      onData(chunk.toString(), result)
    })

    response.body.on('end', resolve)
  })
  return result
}

describe('app dir - rsc external dependency', () => {
  let next: NextInstance

  if ((global as any).isNextDeploy) {
    it('should skip for deploy mode for now', () => {})
    return
  }

  beforeAll(async () => {
    next = await createNext({
      files: new FileRef(path.join(__dirname, './rsc-external')),
      dependencies: {
        react: 'latest',
        'react-dom': 'latest',
      },
      packageJson: {
        scripts: {
          setup: `cp -r ./node_modules_bak/* ./node_modules`,
          build: 'yarn setup && next build',
          dev: 'yarn setup && next dev',
          start: 'next start',
        },
      },
      installCommand: 'yarn',
      startCommand: (global as any).isNextDev ? 'yarn dev' : 'yarn start',
      buildCommand: 'yarn build',
    })
  })
  afterAll(() => next.destroy())

  const { isNextDeploy } = global as any
  const isReact17 = process.env.NEXT_TEST_REACT_VERSION === '^17'
  if (isNextDeploy || isReact17) {
    it('should skip tests for next-deploy and react 17', () => {})
    return
  }

  it('should be able to opt-out 3rd party packages being bundled in server components', async () => {
    await fetchViaHTTP(next.url, '/react-server/optout').then(
      async (response) => {
        const result = await resolveStreamResponse(response)
        expect(result).toContain('Server: index.default')
        expect(result).toContain('Server subpath: subpath.default')
        expect(result).toContain('Client: index.default')
        expect(result).toContain('Client subpath: subpath.default')
      }
    )
  })

  it('should handle external async module libraries correctly', async () => {
    const clientHtml = await renderViaHTTP(next.url, '/external-imports/client')
    const serverHtml = await renderViaHTTP(next.url, '/external-imports/server')
    const sharedHtml = await renderViaHTTP(next.url, '/shared-esm-dep')

    expect(clientHtml).toContain('module type:esm-export')
    expect(clientHtml).toContain('export named:named')
    expect(clientHtml).toContain('export value:123')
    expect(clientHtml).toContain('export array:4,5,6')
    expect(clientHtml).toContain('export object:{x:1}')

    // support esm module imports on server side, and indirect imports from shared components
    expect(serverHtml).toContain('random-module-instance')
    expect(sharedHtml).toContain(
      'node_modules instance from client module random-module-instance'
    )
  })

  it('should resolve the subset react in server components based on the react-server condition', async () => {
    await fetchViaHTTP(next.url, '/react-server').then(async (response) => {
      const result = await resolveStreamResponse(response)
      expect(result).toContain('Server: <!-- -->subset')
      expect(result).toContain('Client: <!-- -->full')
    })
  })

  it('should resolve 3rd party package exports based on the react-server condition', async () => {
    await fetchViaHTTP(next.url, '/react-server/3rd-party-package').then(
      async (response) => {
        const result = await resolveStreamResponse(response)

        // Package should be resolved based on the react-server condition,
        // as well as package's internal & external dependencies.
        expect(result).toContain(
          'Server: index.react-server:react.subset:dep.server'
        )
        expect(result).toContain('Client: index.default:react.full:dep.default')

        // Subpath exports should be resolved based on the condition too.
        expect(result).toContain('Server subpath: subpath.react-server')
        expect(result).toContain('Client subpath: subpath.default')
      }
    )
  })

  it('should correctly collect global css imports and mark them as side effects', async () => {
    await fetchViaHTTP(next.url, '/css/a').then(async (response) => {
      const result = await resolveStreamResponse(response)

      // It should include the global CSS import
      expect(result).toMatch(/\.css/)
    })
  })
})