如何修复未定义的错误?NodeJS，JWT

Question

const express = require("express");
const jwt = require("jsonwebtoken");
const { type } = require("os");
const app = express();
app.get("/api", (req,res) => {
res.json({
message: "Welcome to the API"
});
});
app.post("/api/posts", (req,res) => {
res.json({
message: "Post has been created.."
});
});
app.post("/api/login", verifyToken, (req,res) => {
// Mock User
const user = {
id: 24,
username: "Jonah",
email: "[e-mail]"
}
jwt.sign({user}, "secretkey", (err, token) => {
res.json({
token
});
});
});  
// Verify Token
function verifyToken(req,res,next) {
// Get authorization header value
const bearerHeader = req.headers["authorization"];
}
// Check if bearer is undefined
if(typeof bearerHeader !== "undefined") {
}else{
// Forbidden
res.sendStatus(403);
}
app.listen(5000, () => console.log("Server is listening on port 5000.."));

我想用JWT进行Node.js API身份验证，当我用if/else方法检查时；res未被定义"；，我如何定义这个"；res"；并修复错误？

res.sendStatus(403(；^

ReferenceError:res未定义

Answer 1

您的verifyToken()函数中存在一些不正确的支撑。更改此项：

// Verify Token
function verifyToken(req,res,next) {
// Get authorization header value
const bearerHeader = req.headers["authorization"];
}
// Check if bearer is undefined
if(typeof bearerHeader !== "undefined") {
}else{
// Forbidden
res.sendStatus(403);
}

到此：

// Verify Token
function verifyToken(req,res,next) {
// Get authorization header value
const bearerHeader = req.headers["authorization"];
// Check if bearer is undefined
// FIX THIS: need to not just check if it's undefined, but if
//    its valid
if(typeof bearerHeader !== "undefined") {
next();
} else {
// Forbidden
res.sendStatus(403);
}
}