Capacitor CLI读取配置文件时出现ReferenceError: await未定义问题

问题场景 #

使用Capacitor CLI读取capacitor.config.ts文件时触发ReferenceError: await is not defined错误，此前在Vite中遇到过相同问题但无法复现。

报错的capacitor.config.ts代码 #

import type {AppConfig} from '../../utils/app-config';
import {resolveAllConfigs} from '../../utils/app-config';
import type {CapacitorConfig} from '@capacitor/cli';

const appConfig: AppConfig = (await resolveAllConfigs({}));

export default ({} as CapacitorConfig);

错误信息 #

[error] Parsing capacitor.config.ts failed.

ReferenceError: await is not defined
at Object.
(/Users/oliver/Desktop/temp/app-mobile/mobile/packages/app/capacitor.config.ts:4:19)
at Module._compile (node:internal/modules/cjs/loader:1256:14)
at require.extensions..ts
(/Users/oliver/Desktop/temp/app-mobile/mobile/node_modules/.pnpm/@capacitor+cli@5.4.1/node_modules/@capacitor/cli/dist/util/node.js:34:72)
at Module.load (node:internal/modules/cjs/loader:1119:32)
at Module._load (node:internal/modules/cjs/loader:960:12)
at Module.require (node:internal/modules/cjs/loader:1143:19)
at require (node:internal/modules/cjs/helpers:121:18)
at requireTS
(/Users/oliver/Desktop/temp/app-mobile/mobile/node_modules/.pnpm/@capacitor+cli@5.4.1/node_modules/@capacitor/cli/dist/util/node.js:36:15)
at loadExtConfigTS
(/Users/oliver/Desktop/temp/app-mobile/mobile/node_modules/.pnpm/@capacitor+cli@5.4.1/node_modules/@capacitor/cli/dist/config.js:89:54)
at loadExtConfig
(/Users/oliver/Desktop/temp/app-mobile/mobile/node_modules/.pnpm/@capacitor+cli@5.4.1/node_modules/@capacitor/cli/dist/config.js:123:16)

相关工具代码（app-config.ts） #

import type {AppConfig, AppConfigEnv} from './app-config';
import * as cc from 'cosmiconfig';
import {TypeScriptLoader} from 'cosmiconfig-typescript-loader';
import _ from 'lodash';

const COSMICONFIG_LOADERS: cc.Loaders = {'.ts': TypeScriptLoader()};

const resolveConfig = (async(moduleName: string, env: AppConfigEnv): Promise<AppConfig> => {
  const explorer: cc.PublicExplorer = cc.cosmiconfig(moduleName, {loaders: COSMICONFIG_LOADERS});
  const result: (cc.CosmiconfigResult | null) = (await explorer.search());

  if(!result) {
    throw (new Error(`Could not find a valid ${moduleName} configuration.`));
  }

  if((typeof result.config === 'object')) {
    // Object or Promise.
    return (await result.config);
  } else if((typeof result.config === 'function')) {
    // Function.
    return (await result.config(env));
  }

  throw (new Error(`Invalid ${moduleName} configuration.`));
});

const resolveAllConfigs = (async(env: AppConfigEnv): Promise<AppConfig> => {
  const isDevelopment: boolean = (env.mode === 'development');

  return _.merge(
      (await resolveConfig('app', env)),
      ...(isDevelopment ? [
        (await resolveConfig('app--local-default', env)),
        (await resolveConfig('app--local', env))
      ] : [])
  );
});

export {
  resolveConfig,
  resolveAllConfigs
};

问题原因 #

await关键字仅能在async函数内部使用，你在capacitor.config.ts的模块顶层直接调用await resolveAllConfigs({})，而Capacitor CLI依赖的Node.js CommonJS模块系统默认不支持顶层await，加载逻辑也未兼容该特性，因此触发错误。

解决方法 #

方案1：用立即执行异步函数（IIFE）包裹逻辑 #

将顶层await放入IIFE中执行，避免直接在模块顶层使用：

import type {AppConfig} from '../../utils/app-config';
import {resolveAllConfigs} from '../../utils/app-config';
import type {CapacitorConfig} from '@capacitor/cli';

let appConfig: AppConfig;

(async () => {
  appConfig = await resolveAllConfigs({});
  // 若需要基于appConfig生成Capacitor配置，可在此处处理
})();

export default ({} as CapacitorConfig);

方案2：导出异步函数（推荐，适配Capacitor 5+） #

Capacitor 5及以上版本支持导出返回CapacitorConfig的异步函数，可直接在函数内使用await：

import type {AppConfig} from '../../utils/app-config';
import {resolveAllConfigs} from '../../utils/app-config';
import type {CapacitorConfig} from '@capacitor/cli';

export default async (): Promise<CapacitorConfig> => {
  const appConfig: AppConfig = await resolveAllConfigs({});
  
  // 基于appConfig生成你的Capacitor配置
  return {
    appId: appConfig.appId,
    appName: appConfig.appName,
    // 其他配置项
  } as CapacitorConfig;
};

额外说明 #

即使Node.js v14.8+支持顶层await，但Capacitor CLI的配置加载逻辑并未适配该特性，因此上述两种方案是更稳妥的解决方式。

内容的提问来源于stack exchange，提问作者Oliver