由于 route.get() 文件错误，nodemon 不断崩溃

Question

我被困在fourth MDN tutorial 的最后一点，您将在其中运行 nodemon 以检查您的路由/控制器，看看您在本地主机上运行它们做了什么。它说我有一个路由错误，需要一个未定义对象的回调函数。我已经用谷歌搜索并访问了课程的 GitHub，并自己浏览并重做代码并阅读了代码块，但仍然卡住了。这似乎是关于我的路线目录的作者 GET 部分的问题。我已经在底部列出了代码。

由于我复制并粘贴了整个课程并按照说明进行操作，因此我无法弄清楚哪里出了问题。我什至认为其中一个问题是我没有将它放入本地存储库并做到了，但事实证明它实际上是同名父文件夹中的重复文件，所以我不得不 cd express-locallibrary-教程，然后终于能够找到所需的文件。

________@Bridgettes-MacBook-Air express-locallibrary-tutorial % DEBUG=express-locallibrary-tutorial:* npm run devstart

> express-locallibrary-tutorial@0.0.0 devstart /Users/_____/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial
> nodemon ./bin/www

[nodemon] 2.0.12
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node ./bin/www`
/Users/_______/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial/node_modules/express/lib/router/route.js:202
        throw new Error(msg);
        ^

Error: Route.get() requires a callback function but got a [object Undefined]
    at Route.<computed> [as get] (/Users/_______/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial/node_modules/express/lib/router/route.js:202:15)
    at Function.proto.<computed> [as get] (/Users/_________/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial/node_modules/express/lib/router/index.js:510:19)
    at Object.<anonymous> (/Users/___________/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial/routes/catalog.js:56:8)
    at Module._compile (internal/modules/cjs/loader.js:1085:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:14)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (internal/modules/cjs/helpers.js:92:18)
    at Object.<anonymous> (/Users/__________/Desktop/express-locallibrary-tutorial/express-locallibrary-tutorial/app.js:13:21)
    at Module._compile (internal/modules/cjs/loader.js:1085:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:14)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (internal/modules/cjs/helpers.js:92:18)
[nodemon] app crashed - waiting for file changes before starting...

第 56:8 行

// GET request to update Author.
router.get('/author/:id/update', author_controller.author_update_get);

13:21 行

var catalogRouter = require('./routes/catalog');  //Import routes for "catalog" area of site

Answer 1

问题在于您的路由，在目录路由器文件中，您没有导入任何文件或没有将其传递给 router.get() 中间件。 假设您在目录路由器中导出了 author_list。那么你的get方法应该是这样的。

const {author_List} = require('../controllers/authController')
router.get('/authorList', author_List)
module.exports = router

如果我能看到你的路由器文件，我会更容易解释。