运行本地移动端自动化测试时'onPrepare'钩子服务失败求助

环境配置 #

package.json #

{
  "name": "my-new-project",
  "type": "module",
  "devDependencies": {
    "@wdio/appium-service": "^8.11.2",
    "@wdio/cli": "^8.11.2",
    "@wdio/local-runner": "^8.11.2",
    "@wdio/mocha-framework": "^8.11.0",
    "@wdio/spec-reporter": "^8.11.2",
    "appium": "^2.0.0-rc.3",
    "appium-uiautomator2-driver": "^2.29.0"
  },
  "scripts": {
    "wdio": "wdio run ./wdio.conf.js"
  }
}

wdio.conf.js #

export const config = {
    runner: 'local',
    
    port: 4724,
    path: '/',
    specs: [
        './local_test.js'
    ],
    
    exclude: [
        // 'path/to/excluded/files'
    ],

    maxInstances: 10,

    capabilities: [{
        "platformName": "Android",
        "appium:platformVersion": "11",
        "appium:deviceName": "Redmi Note 11",
        "appium:automationName": "UIAutomator2",
        "appium:app": "C:\\VisualSC\\i_g_3_YT\\WikipediaSample.apk",
        "appium:udid": "my_udid",
      }],

    logLevel: 'error',

    bail: 0,

    baseUrl: 'http://localhost',

    waitforTimeout: 20000,

    connectionRetryTimeout: 120000,

    connectionRetryCount: 3,

    services: ['appium'],
    
    framework: 'mocha',

    reporters: ['spec'],

    mochaOpts: {
        ui: 'bdd',
        timeout: 60000
    },
}

执行命令与错误信息 #

执行命令：

PS C:\VisualSC\i_g_3_YT> npm run wdio

错误输出：

2023-06-25T23:43:13.006Z ERROR @wdio/cli:utils: A service failed in the 'onPrepare' hook
Error: Appium exited before timeout (exit code: 1)
    at ChildProcess.<anonymous> (file:///C:/VisualSC/i_g_3_YT/node_modules/@wdio/appium-service/build/launcher.js:116:22)
    at Object.onceWrapper (node:events:628:26)
    at ChildProcess.emit (node:events:513:28)
    at ChildProcess.emit (node:domain:489:12)
    at ChildProcess._handle.onexit (node:internal/child_process:291:12)

Continue...
[0-0] Error: "ts-node/esm/transpile-only 'resolve'" did not call the next hook in its chain and did not explicitly signal a short circuit. If this is intentional, include `shortCircuit: true` in the hook's return.
[0-0]     at new NodeError (node:internal/errors:399:5)
[0-0]     at ESMLoader.resolve (node:internal/modules/esm/loader:846:13)
[0-0]     at ESMLoader.getModuleJob (node:internal/modules/esm/loader:424:7)
[0-0] FAILED

Spec Files:      0 passed, 1 failed, 1 total (100% completed) in 00:00:07

问题分析与解决步骤 #

1. 修复ES模块加载错误 #

错误源于ts-node的ES模块解析钩子未正确配置，需添加shortCircuit: true声明：

• 在项目根目录创建tsconfig.json，写入以下配置：

  {
    "compilerOptions": {
      "module": "ESNext",
      "moduleResolution": "node",
      "target": "ES2020",
      "esModuleInterop": true
    },
    "ts-node": {
      "esm": true,
      "experimentalSpecifierResolution": "node",
      "transpileOnly": true,
      "resolve": {
        "shortCircuit": true
      }
    }
  }
  

• 或者修改package.json中的wdio启动命令，添加加载器配置参数：

  "scripts": {
    "wdio": "node --loader ts-node/esm --experimental-specifier-resolution=node wdio run ./wdio.conf.js"
  }
  

2. 解决Appium服务启动失败问题 #

Appium退出码1通常是端口冲突或驱动安装异常：

• 关闭Appium GUI：若已打开Appium GUI，它会占用4724端口，导致WDIO的appium服务无法启动，关闭后重新执行命令。
• 重新安装Appium驱动：Appium 2.x要求用官方命令安装驱动，而非npm直接安装，执行以下命令：

  npm uninstall appium-uiautomator2-driver
  appium driver install uiautomator2
  

• 更换端口：如果4724端口仍被占用，修改wdio.conf.js中的port字段为其他未被占用的端口（比如4725）。

3. 验证修复 #

重新执行npm run wdio，检查错误是否消除，测试能否正常运行。

内容的提问来源于stack exchange，提问作者A. K.