rsnext/test/lib/next-modes/base.ts

import os from 'os'
import path from 'path'
import fs from 'fs-extra'
import treeKill from 'tree-kill'
import type { NextConfig } from 'next'
import { FileRef } from '../e2e-utils'
import { ChildProcess } from 'child_process'
import { createNextInstall } from '../create-next-install'
import { Span } from 'next/src/trace'
import webdriver from '../next-webdriver'
import { renderViaHTTP, fetchViaHTTP } from 'next-test-utils'
import cheerio from 'cheerio'
import { BrowserInterface } from '../browsers/base'

type Event = 'stdout' | 'stderr' | 'error' | 'destroy'
export type InstallCommand =
  | string
  | ((ctx: { dependencies: { [key: string]: string } }) => string)

export type PackageJson = {
  dependencies?: { [key: string]: string }
  [key: string]: unknown
}
export interface NextInstanceOpts {
  files: FileRef | string | { [filename: string]: string | FileRef }
  dependencies?: { [name: string]: string }
  packageJson?: PackageJson
  nextConfig?: NextConfig
  installCommand?: InstallCommand
  buildCommand?: string
  startCommand?: string
  env?: Record<string, string>
  dirSuffix?: string
  turbo?: boolean
}

/**
 * Omit the first argument of a function
 */
type OmitFirstArgument<F> = F extends (
  firstArgument: any,
  ...args: infer P
) => infer R
  ? (...args: P) => R
  : never

export class NextInstance {
  protected files: FileRef | { [filename: string]: string | FileRef }
  protected nextConfig?: NextConfig
  protected installCommand?: InstallCommand
  protected buildCommand?: string
  protected startCommand?: string
  protected dependencies?: PackageJson['dependencies'] = {}
  protected events: { [eventName: string]: Set<any> } = {}
  public testDir: string
  protected isStopping: boolean = false
  protected isDestroyed: boolean = false
  protected childProcess: ChildProcess
  protected _url: string
  protected _parsedUrl: URL
  protected packageJson?: PackageJson = {}
  protected basePath?: string
  protected env?: Record<string, string>
  public forcedPort?: string
  public dirSuffix: string = ''

  constructor(opts: NextInstanceOpts) {
    Object.assign(this, opts)

    if (!(global as any).isNextDeploy) {
      this.env = {
        ...this.env,
        // remove node_modules/.bin repo path from env
        // to match CI $PATH value and isolate further
        PATH: process.env.PATH.split(path.delimiter)
          .filter((part) => {
            return !part.includes(path.join('node_modules', '.bin'))
          })
          .join(path.delimiter),
      }
    }
  }

  protected async writeInitialFiles() {
    // Handle case where files is a directory string
    const files =
      typeof this.files === 'string' ? new FileRef(this.files) : this.files
    if (files instanceof FileRef) {
      // if a FileRef is passed directly to `files` we copy the
      // entire folder to the test directory
      const stats = await fs.stat(files.fsPath)

      if (!stats.isDirectory()) {
        throw new Error(
          `FileRef passed to "files" in "createNext" is not a directory ${files.fsPath}`
        )
      }
      await fs.copy(files.fsPath, this.testDir)
    } else {
      for (const filename of Object.keys(files)) {
        const item = files[filename]
        const outputFilename = path.join(this.testDir, filename)

        if (typeof item === 'string') {
          await fs.ensureDir(path.dirname(outputFilename))
          await fs.writeFile(outputFilename, item)
        } else {
          await fs.copy(item.fsPath, outputFilename)
        }
      }
    }
  }

  protected async createTestDir({
    skipInstall = false,
    parentSpan,
  }: {
    skipInstall?: boolean
    parentSpan: Span
  }) {
    if (this.isDestroyed) {
      throw new Error('next instance already destroyed')
    }
    require('console').log(`Creating test directory with isolated next...`)

    await parentSpan
      .traceChild('createTestDir')
      .traceAsyncFn(async (rootSpan) => {
        const skipIsolatedNext = !!process.env.NEXT_SKIP_ISOLATE
        const tmpDir = skipIsolatedNext
          ? path.join(__dirname, '../../tmp')
          : process.env.NEXT_TEST_DIR || (await fs.realpath(os.tmpdir()))
        this.testDir = path.join(
          tmpDir,
          `next-test-${Date.now()}-${(Math.random() * 1000) | 0}${
            this.dirSuffix
          }`
        )

        const reactVersion = process.env.NEXT_TEST_REACT_VERSION || 'latest'
        const finalDependencies = {
          react: reactVersion,
          'react-dom': reactVersion,
          '@types/react': reactVersion,
          typescript: 'latest',
          '@types/node': 'latest',
          ...this.dependencies,
          ...this.packageJson?.dependencies,
        }

        if (skipInstall) {
          const pkgScripts = (this.packageJson['scripts'] as {}) || {}
          await fs.ensureDir(this.testDir)
          await fs.writeFile(
            path.join(this.testDir, 'package.json'),
            JSON.stringify(
              {
                ...this.packageJson,
                dependencies: {
                  ...finalDependencies,
                  next:
                    process.env.NEXT_TEST_VERSION ||
                    require('next/package.json').version,
                },
                scripts: {
                  // since we can't get the build id as a build artifact, make it
                  // available under the static files
                  'post-build': 'cp .next/BUILD_ID .next/static/__BUILD_ID',
                  ...pkgScripts,
                  build:
                    (pkgScripts['build'] || this.buildCommand || 'next build') +
                    ' && pnpm post-build',
                },
              },
              null,
              2
            )
          )
        } else {
          if (
            process.env.NEXT_TEST_STARTER &&
            !this.dependencies &&
            !this.installCommand &&
            !this.packageJson &&
            !(global as any).isNextDeploy
          ) {
            await fs.copy(process.env.NEXT_TEST_STARTER, this.testDir)
          } else if (!skipIsolatedNext) {
            this.testDir = await createNextInstall({
              parentSpan: rootSpan,
              dependencies: finalDependencies,
              installCommand: this.installCommand,
              packageJson: this.packageJson,
              dirSuffix: this.dirSuffix,
            })
          }
          require('console').log('created next.js install, writing test files')
        }

        await rootSpan
          .traceChild('writeInitialFiles')
          .traceAsyncFn(async () => {
            await this.writeInitialFiles()
          })

        let nextConfigFile = Object.keys(this.files).find((file) =>
          file.startsWith('next.config.')
        )

        if (await fs.pathExists(path.join(this.testDir, 'next.config.js'))) {
          nextConfigFile = 'next.config.js'
        }

        if (nextConfigFile && this.nextConfig) {
          throw new Error(
            `nextConfig provided on "createNext()" and as a file "${nextConfigFile}", use one or the other to continue`
          )
        }

        if (
          this.nextConfig ||
          ((global as any).isNextDeploy && !nextConfigFile)
        ) {
          const functions = []

          await fs.writeFile(
            path.join(this.testDir, 'next.config.js'),
            `
        module.exports = ` +
              JSON.stringify(
                {
                  ...this.nextConfig,
                } as NextConfig,
                (key, val) => {
                  if (typeof val === 'function') {
                    functions.push(
                      val
                        .toString()
                        .replace(
                          new RegExp(`${val.name}[\\s]{0,}\\(`),
                          'function('
                        )
                    )
                    return `__func_${functions.length - 1}`
                  }
                  return val
                },
                2
              ).replace(/"__func_[\d]{1,}"/g, function (str) {
                return functions.shift()
              })
          )
        }

        if ((global as any).isNextDeploy) {
          const fileName = path.join(
            this.testDir,
            nextConfigFile || 'next.config.js'
          )
          const content = await fs.readFile(fileName, 'utf8')

          if (content.includes('basePath')) {
            this.basePath =
              content.match(/['"`]?basePath['"`]?:.*?['"`](.*?)['"`]/)?.[1] ||
              ''
          }

          await fs.writeFile(
            fileName,
            `${content}\n` +
              `
          // alias __NEXT_TEST_MODE for next-deploy as "_" is not a valid
          // env variable during deploy
          if (process.env.NEXT_PRIVATE_TEST_MODE) {
            process.env.__NEXT_TEST_MODE = process.env.NEXT_PRIVATE_TEST_MODE
          }
        `
          )
        }
      })
  }

  public async clean() {
    if (this.childProcess) {
      throw new Error(`stop() must be called before cleaning`)
    }

    const keptFiles = [
      'node_modules',
      'package.json',
      'yarn.lock',
      'pnpm-lock.yaml',
    ]
    for (const file of await fs.readdir(this.testDir)) {
      if (!keptFiles.includes(file)) {
        await fs.remove(path.join(this.testDir, file))
      }
    }
    await this.writeInitialFiles()
  }

  public async build(): Promise<{ exitCode?: number; cliOutput?: string }> {
    throw new Error('Not implemented')
  }
  public async export(args?: {
    outdir?: string
  }): Promise<{ exitCode?: number; cliOutput?: string }> {
    throw new Error('Not implemented')
  }
  public async setup(parentSpan: Span): Promise<void> {}
  public async start(useDirArg: boolean = false): Promise<void> {}
  public async stop(): Promise<void> {
    this.isStopping = true
    if (this.childProcess) {
      let exitResolve
      const exitPromise = new Promise((resolve) => {
        exitResolve = resolve
      })
      this.childProcess.addListener('exit', () => {
        exitResolve()
      })
      await new Promise<void>((resolve) => {
        treeKill(this.childProcess.pid, 'SIGKILL', (err) => {
          if (err) {
            require('console').error('tree-kill', err)
          }
          resolve()
        })
      })
      this.childProcess.kill('SIGKILL')
      await exitPromise
      this.childProcess = undefined
      require('console').log(`Stopped next server`)
    }
  }

  public async destroy(): Promise<void> {
    if (this.isDestroyed) {
      throw new Error(`next instance already destroyed`)
    }
    this.isDestroyed = true
    this.emit('destroy', [])
    await this.stop()

    if (process.env.TRACE_PLAYWRIGHT) {
      await fs
        .copy(
          path.join(this.testDir, '.next/trace'),
          path.join(
            __dirname,
            '../../traces',
            `${path
              .relative(
                path.join(__dirname, '../../'),
                process.env.TEST_FILE_PATH
              )
              .replace(/\//g, '-')}`,
            `next-trace`
          )
        )
        .catch(() => {})
    }

    if (!process.env.NEXT_TEST_SKIP_CLEANUP) {
      await fs.remove(this.testDir)
    }
    require('console').log(`destroyed next instance`)
  }

  public get url() {
    return this._url
  }

  public get appPort() {
    return this._parsedUrl.port
  }

  public get buildId(): string {
    return ''
  }

  public get cliOutput(): string {
    return ''
  }

  // TODO: block these in deploy mode
  public async readFile(filename: string) {
    return fs.readFile(path.join(this.testDir, filename), 'utf8')
  }
  public async readJSON(filename: string) {
    return fs.readJSON(path.join(this.testDir, filename))
  }
  public async patchFile(filename: string, content: string) {
    const outputPath = path.join(this.testDir, filename)
    await fs.ensureDir(path.dirname(outputPath))
    return fs.writeFile(outputPath, content)
  }
  public async renameFile(filename: string, newFilename: string) {
    return fs.rename(
      path.join(this.testDir, filename),
      path.join(this.testDir, newFilename)
    )
  }
  public async deleteFile(filename: string) {
    return fs.remove(path.join(this.testDir, filename))
  }

  /**
   * Create new browser window for the Next.js app.
   */
  public async browser(
    ...args: Parameters<OmitFirstArgument<typeof webdriver>>
  ): Promise<BrowserInterface> {
    return webdriver(this.url, ...args)
  }

  /**
   * Fetch the HTML for the provided page. This is a shortcut for `renderViaHTTP().then(html => cheerio.load(html))`.
   */
  public async render$(
    ...args: Parameters<OmitFirstArgument<typeof renderViaHTTP>>
  ): Promise<ReturnType<typeof cheerio.load>> {
    const html = await renderViaHTTP(this.url, ...args)
    return cheerio.load(html)
  }

  /**
   * Fetch the HTML for the provided page. This is a shortcut for `fetchViaHTTP().then(res => res.text())`.
   */
  public async render(
    ...args: Parameters<OmitFirstArgument<typeof renderViaHTTP>>
  ) {
    return renderViaHTTP(this.url, ...args)
  }

  /**
   * Performs a fetch request to the NextInstance with the options provided.
   *
   * @param pathname the pathname on the NextInstance to fetch
   * @param opts the optional options to pass to the underlying fetch
   * @returns the fetch response
   */
  public async fetch(
    pathname: string,
    opts?: import('node-fetch').RequestInit
  ) {
    return fetchViaHTTP(this.url, pathname, null, opts)
  }

  public on(event: Event, cb: (...args: any[]) => any) {
    if (!this.events[event]) {
      this.events[event] = new Set()
    }
    this.events[event].add(cb)
  }

  public off(event: Event, cb: (...args: any[]) => any) {
    this.events[event]?.delete(cb)
  }

  protected emit(event: Event, args: any[]) {
    this.events[event]?.forEach((cb) => {
      cb(...args)
    })
  }
}