为什么Joi验证器中的错误消息出现在邮递员中，而没有出现在终端中？

Question

由于某种奇怪的原因，错误消息没有显示在终端中，而出现在邮递员中。我正在使用joi验证程序。请让我知道我做错了什么！谢谢！

const Joi = require("joi");
const express = require("express");
app = express();

app.use(express.json());

const courses= [
    { id:1, name:"course1"},
    { id:2, name:"course2"},
    { id:3, name:"course3"}
]

app.get("/", function(req,res) {
    res.send("Hello Worlds");
});

app.get("/api/courses", function(req,res){
    res.send(courses);
});

app.get("/api/courses/:id", function(req,res) {
    const course =courses.find(c=>c.id===parseInt(req.params.id))
    if(!course) res.status(404).send("Course with given id was not found...");
    res.send(course);
});

app.post("/api/courses", function(req,res) {
    const schema = {
        name: Joi.string().min(3).required()
    };

    const result = Joi.validate(req.body, schema);
    if (result.error ) {
        res.status(400).send(result.error.details[0].message);
        return;

    }
    const course= {
        id: courses.length +1,
        name:req.body.name
    };
    courses.push(course);
    res.send(course);
})





Port = process.env.Port || 2000;
app.listen(Port, console.log(`Listening on port ${Port}`));

下面是我要在终端中显示的消息键的路径：

"isJoi": true,
"name": "ValidationError",
"details": [
    {
        "message": "\"name\" length must be at least 3 characters long",
        "path": [
            "name"
        ],
        "type": "string.min",
        "context": {
            "limit": 3,
            "value": "r",
            "key": "name",
            "label": "name"
        }
    }
],
"_object": {
    "name": "r"
}