Question

我想将一些模块导出到我的 app.js 并使用它。但我抓住了一个例外：

'getUserFromDB未定义'

所以，这是我的 app.js ：

var api = require('./routes/API')
app.use(api.router)

API.js ：

const router = require('express').Router()
function getUserFromDB(login){
  // some actions
}
router.get('/get-db', (req, res) => {
  getUserFromDB('abcde123')
})
module.exports = {
    router: router,
    getUserFromDB: getUserFromDB
}

完整堆栈跟踪：

Trace: Trace before app.use(api.router)
    at Object.<anonymous> (\my-project\build\dev-server.js:74:9)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.runMain (module.js:604:10)
    at run (bootstrap_node.js:389:7)
    at startup (bootstrap_node.js:149:9)
    at bootstrap_node.js:502:3
ReferenceError: getUserFromDB is not defined
    at NativeConnection.<anonymous> (\my-project\build\dev-server.js:65:5)
    at NativeConnection.g (events.js:292:16)
    at emitNone (events.js:86:13)
    at NativeConnection.emit (events.js:185:7)
    at open (\my-project\node_modules\mongoose\lib\connection.js:686:11)
    at NativeConnection.Connection.onOpen (\my-project\node_modules\mongoose\lib\connection.js:695:5)
    at \my-project\node_modules\mongoose\lib\connection.js:655:11
    at \my-project\node_modules\mongoose\lib\drivers\node-mongodb-native\connection.js:71:5
    at \my-project\node_modules\mongodb\lib\db.js:238:5
    at Server.connectHandler (\my-project\node_modules\mongodb\lib\server.js:324:7)
    at Server.g (events.js:292:16)
    at emitOne (events.js:96:13)
    at Server.emit (events.js:188:7)
    at \my-project\node_modules\mongodb-core\lib\topologies\server.js:300:14
    at \my-project\node_modules\mongodb-core\lib\connection\pool.js:469:18
    at _combinedTickCallback (internal/process/next_tick.js:73:7)
    at process._tickCallback (internal/process/next_tick.js:104:9)
\my-project\node_modules\mongodb\lib\server.js:327
      process.nextTick(function() { throw err; })

我不知道该怎么做。

Answer 1

const router = require('express').Router()
const getUserFromDB = function(login){
  // some actions
}
router.get('/get-db', (req, res) => {
  getUserFromDB('abcde123')
})
module.exports = {
    router: router,
    getUserFromDB: getUserFromDB
}

Answer 2

请尝试以下

const router = require('express').Router()
function getUserFromDB(login){
   // some actions
   return login; 
}
router.get('/get-db', (req, res) => {
  res.send(getUserFromDB('abcde123'));
})
module.exports = {
  router: router,
  getUserFromDB: getUserFromDB
}

在app.js

中更改为以下内容

app.use('/', api.router);

使用工作功能正确导出模块。节点js

2 个答案: