部署Firebase Functions/Hosting时遭遇未使用变量错误

问题重现 #

执行firebase deploy时出现以下ESLint错误：

10:8  error  'onRequest' is assigned a value but never used  no-unused-vars

 11:7  error  'logger' is assigned a value but never used     no-unused-vars

随后触发预部署失败：

functions predeploy error: Command terminated with non-zero exit code 1

问题出在Functions目录下的index.js文件，当前内容为：

/**
 * Import function triggers from their respective submodules:
 *
 * const {onCall} = require("firebase-functions/v2/https");
 * const {onDocumentWritten} = require("firebase-functions/v2/firestore");
 *
 * See a full list of supported triggers at https://firebase.google.com/docs/functions
 */

const {onRequest} = require("firebase-functions/v2/https");
const logger = require("firebase-functions/logger");

// Create and deploy your first functions
// https://firebase.google.com/docs/functions/get-started

// exports.helloWorld = onRequest((request, response) => {
//   logger.info("Hello logs!", {structuredData: true});
//   response.send("Hello from Firebase!");
// });

修复方案 #

方案1：启用示例云函数（推荐） #

把文件中被注释的示例函数取消注释，让onRequest和logger被正常调用，修改后的index.js如下：

/**
 * Import function triggers from their respective submodules:
 *
 * const {onCall} = require("firebase-functions/v2/https");
 * const {onDocumentWritten} = require("firebase-functions/v2/firestore");
 *
 * See a full list of supported triggers at https://firebase.google.com/docs/functions
 */

const {onRequest} = require("firebase-functions/v2/https");
const logger = require("firebase-functions/logger");

// Create and deploy your first functions
// https://firebase.google.com/docs/functions/get-started

exports.helloWorld = onRequest((request, response) => {
  logger.info("Hello logs!", {structuredData: true});
  response.send("Hello from Firebase!");
});

方案2：删除未使用的导入（如果不需要云函数） #

如果你的项目完全不需要Cloud Functions功能，直接删掉那两行未使用的导入代码，修改后的index.js如下：

/**
 * Import function triggers from their respective submodules:
 *
 * const {onCall} = require("firebase-functions/v2/https");
 * const {onDocumentWritten} = require("firebase-functions/v2/firestore");
 *
 * See a full list of supported triggers at https://firebase.google.com/docs/functions
 */

// Create and deploy your first functions
// https://firebase.google.com/docs/functions/get-started

// exports.helloWorld = onRequest((request, response) => {
//   logger.info("Hello logs!", {structuredData: true});
//   response.send("Hello from Firebase!");
// });

修改完成后，重新执行firebase deploy即可完成部署。

内容的提问来源于stack exchange，提问作者Kacper