ExpressJs响应主体为空

Question

ExpressJs路由响应res.send正在发送，但是响应主体为空。在客户端记录的Promise的then回调中，响应显示一个键为body: null的对象。

如果我尝试在then之后使用res.json()回调，它将永远不会触发。 res.text触发回调，但不传递任何内容。

有人知道为什么res.send发送一个空对象吗？

服务器

//configure env variables
require("dotenv").config();

//import packages
var express = require("express");
var bodyParser = require("body-parser");
var cors = require("cors");

//setup app
const app = express();
const port = process.env.PORT || 5000;

//setup bodyparser
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

//Setup CORS
app.use(cors());
app.options("*", cors()); // include before other routes

//Connect functions to API routes
app.post("/charge",     app.post("/charge", (req, res) =>{res.send({asd:"ASDASD"}); });
);

//export app for local testing or lambda serverless running
module.exports = app;

客户端

 fetch(`${backendUrl}/charge`, {
                method: "POST",
                mode: "no-cors",
                headers: {
                    'Accept': 'application/json',
                    "Content-Type": "application/x-www-form-urlencoded"
                },
                body: encodeURIComponent(
                    JSON.stringify({
                        stripeToken: token.id,
                        chargeAmount: Math.round(100 * this.state.donationAmount) // Needs to be an integer in cents
                    })
                )
            })
                .then(res => {
                    console.log(res);
                    return res.text();
                })
                .then(json => {
                    console.log("response is " + json);
                    this.setState({ donationResponse: "Thank you for donating!" });
                })
                .catch(error => {
                    this.setState({
                        donationResponse:
                            "There was an issue processing your request. Please try again later"
                    });
                });