node.js - 猫鼬 findOne() 不返回承诺
问题描述
概括
我正在Udemy 上学习这门课程,最后在 github 上完成这个应用程序。
我被困在第 10 课上,我需要创建一个用户注册 API,然后通过发出 AJAX POST 请求进行测试,当我尝试发出fetch
POST 时,我收到此错误消息。
当我尝试使用节点调试器进行测试时,即node --inspect=0.0.0.0:9229 server.js
这似乎表明它findOne()
没有返回应有的 Promise,即使我可以从我在 Udemy 上做的课程中看到它是。此外,Mongoose 文档说它也返回了一个 Promise。
我已将所有代码上传到GitHub 上的此处,以便更容易重现。但是所有相关的代码和日志也在下面。
环境
- OSX 10.13.3
- 节点 v8.11.1
- MongoDB shell 版本 v4.0.1
- MongoDB服务器版v4.0.1
日志
这是服务器控制台的输出,在我发出获取请求后没有有用的错误消息......
in ~/devconnector
$ (master) npm run debug
> devconnector@1.0.0 debug /Users/holly/devconnector
> node --inspect=0.0.0.0:9229 server.js
Debugger listening on ws://0.0.0.0:9229/22164c98-654b-4056-9bae-9a8b8cf96ddf
For help see https://nodejs.org/en/docs/inspector
(node:1892) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.
Server running on port 5000
MongoDB Connected
Debugger attached.
这是 mongo DB 日志,在我在前端发出 fetch 请求后没有任何输出...
$ mongod
2018-09-09T12:12:03.431+0100 I CONTROL [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] MongoDB starting : pid=1932 port=27017 dbpath=/data/db 64-bit host=hollys-MacBook-Pro.local
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] db version v4.0.1
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] git version: 54f1582fc6eb01de4d4c42f26fc133e623f065fb
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] allocator: system
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] modules: none
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] build environment:
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] distarch: x86_64
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] target_arch: x86_64
2018-09-09T12:12:03.445+0100 I CONTROL [initandlisten] options: {}
2018-09-09T12:12:03.446+0100 I STORAGE [initandlisten] Detected data files in /data/db created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
2018-09-09T12:12:03.446+0100 I STORAGE [initandlisten] wiredtiger_open config: create,cache_size=7680M,session_max=20000,eviction=(threads_min=4,threads_max=4),config_base=false,statistics=(fast),log=(enabled=true,archive=true,path=journal,compressor=snappy),file_manager=(close_idle_time=100000),statistics_log=(wait=0),verbose=(recovery_progress),
2018-09-09T12:12:04.105+0100 I STORAGE [initandlisten] WiredTiger message [1536491524:105407][1932:0x7fffa4bb1340], txn-recover: Main recovery loop: starting at 7/8320
2018-09-09T12:12:04.190+0100 I STORAGE [initandlisten] WiredTiger message [1536491524:190433][1932:0x7fffa4bb1340], txn-recover: Recovering log 7 through 8
2018-09-09T12:12:04.247+0100 I STORAGE [initandlisten] WiredTiger message [1536491524:247607][1932:0x7fffa4bb1340], txn-recover: Recovering log 8 through 8
2018-09-09T12:12:04.290+0100 I STORAGE [initandlisten] WiredTiger message [1536491524:290380][1932:0x7fffa4bb1340], txn-recover: Set global recovery timestamp: 0
2018-09-09T12:12:04.424+0100 I RECOVERY [initandlisten] WiredTiger recoveryTimestamp. Ts: Timestamp(0, 0)
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten]
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten]
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** WARNING: This server is bound to localhost.
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** Remote systems will be unable to connect to this server.
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** Start the server with --bind_ip <address> to specify which IP
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** addresses it should serve responses from, or with --bind_ip_all to
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** bind to all interfaces. If this behavior is desired, start the
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten] ** server with --bind_ip 127.0.0.1 to disable this warning.
2018-09-09T12:12:04.593+0100 I CONTROL [initandlisten]
2018-09-09T12:12:04.750+0100 I FTDC [initandlisten] Initializing full-time diagnostic data capture with directory '/data/db/diagnostic.data'
2018-09-09T12:12:04.754+0100 I NETWORK [initandlisten] waiting for connections on port 27017
2018-09-09T12:12:12.339+0100 I NETWORK [listener] connection accepted from 127.0.0.1:56872 #1 (1 connection now open)
2018-09-09T12:12:12.346+0100 I NETWORK [conn1] received client metadata from 127.0.0.1:56872 conn1: { driver: { name: "nodejs", version: "3.1.4" }, os: { type: "Darwin", name: "darwin", architecture: "x64", version: "17.4.0" }, platform: "Node.js v8.11.1, LE, mongodb-core: 3.1.3" }
这是我的代码...
路线/api/users.js
const express = require("express");
const router = express.Router();
const gravatar = require("gravatar");
const bcrypt = require("bcryptjs");
// Load User model
const User = require("../../models/User");
// @route GET api/users/test
// @desc Tests users route
// @access Public
router.get("/test", (req, res) => res.json({ msg: "Users Works" }));
// @route GET api/users/register
// @desc Register user
// @access Public
router.post("/register", (req, res) => {
// function later(delay) {
// return new Promise(function(resolve) {
// setTimeout(resolve, delay);
// });
// }
// later(1000).then(() => {
// console.log("promise worked!");
// res.json({ msg: "promise worked!" });
// });
User.findOne({ email: req.body.email })
.then(user => {
if (user) {
return res.status(400).json({ email: "Email already exists" });
} else {
const avatar = gravatar.url(req.body.email, {
s: "200", // Size
r: "pg", // Rating
d: "mm" // Default
});
const newUser = new User({
name: req.body.name,
email: req.body.email,
avatar,
password: req.body.password
});
bcrypt.genSalt(10, (err, salt) => {
bcrypt.hash(newUser.password, salt, (err, hash) => {
if (err) throw err;
newUser.password = hash;
newUser
.save()
.then(user => res.json(user))
.catch(err => console.log(err));
});
});
}
})
.catch(err => {
console.log(err);
});
});
module.exports = router;
模型/User.js
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const UserSchema = new Schema({
name: {
type: String,
required: true
},
email: {
type: String,
required: true
},
password: {
type: String,
required: true
},
avatar: {
type: String
},
date: {
type: Date,
default: Date.now
}
});
module.exports = User = mongoose.model("users", UserSchema);
服务器.js
const express = require("express");
const mongoose = require("Mongoose");
const bodyParser = require("body-parser");
const users = require("./routes/api/users");
const profile = require("./routes/api/profile");
const posts = require("./routes/api/posts");
const app = express();
// Body parser middleware
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
// DB Config
const db = require("./config/keys").mongoURI;
// Connect to Mongo DB
mongoose
.connect(db)
.then(() => {
console.log("MongoDB Connected");
})
.catch(err => console.log(err));
app.get("/", (req, res) => res.send("Hello World"));
// Use Routes
app.use("/api/users", users);
app.use("/api/profile", profile);
app.use("/api/posts", posts);
const port = process.env.PORT || 5000;
app.listen(port, () => console.log(`Server running on port ${port}`));
解决方案
问题是您需要在 server.js(“Mongoose”)和 models/User.js(“mongoose”)中使用不同名称的 Mongoose 模块。User
这将创建模块的单独实例,因此由 server.js 建立的连接对模型不可用,并且findOne
调用被卡住等待连接。
所以只需将 server.js 中的那一行更改为:
const mongoose = require("mongoose");
推荐阅读
- php - php每周二更新SQL列的状态
- python - 如何在python中查看value_counts()中的整个列表
- java - java.lang.NullPointerException 错误 witt @Test
- python - 使用 OpenCV 模板匹配 matchTemplate() 查找模板之间的最佳匹配
- flutter - 如何让抽屉推动内容而不是放在上面?
- java - 使用 java 打印时的味道无效
- sql - 返回页面时如何在SQL中使用搜索分页?(Postgres)
- python - 有没有办法使用 FORALL 从数组中插入数据?
- c++ - 如何访问 C++ 类中的私有结构?
- c++ - 使用 LDR 传感器控制带 A4988 驱动电机的步进电机