http-proxy-middleware
Version:
The one-liner node.js proxy middleware for connect, express, next.js and more
51 lines (50 loc) • 1.69 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.fixRequestBody = fixRequestBody;
const querystring = require("querystring");
/**
* Fix proxied body if bodyParser is involved.
*/
function fixRequestBody(proxyReq, req) {
// skip fixRequestBody() when req.readableLength not 0 (bodyParser failure)
if (req.readableLength !== 0) {
return;
}
const requestBody = req.body;
if (!requestBody) {
return;
}
const contentType = proxyReq.getHeader('Content-Type');
if (!contentType) {
return;
}
const writeBody = (bodyData) => {
proxyReq.setHeader('Content-Length', Buffer.byteLength(bodyData));
proxyReq.write(bodyData);
};
// Use if-elseif to prevent multiple writeBody/setHeader calls:
// Error: "Cannot set headers after they are sent to the client"
if (contentType.includes('application/json') || contentType.includes('+json')) {
writeBody(JSON.stringify(requestBody));
}
else if (contentType.includes('application/x-www-form-urlencoded')) {
writeBody(querystring.stringify(requestBody));
}
else if (contentType.includes('multipart/form-data')) {
writeBody(handlerFormDataBodyData(contentType, requestBody));
}
}
/**
* format FormData data
* @param contentType
* @param data
* @returns
*/
function handlerFormDataBodyData(contentType, data) {
const boundary = contentType.replace(/^.*boundary=(.*)$/, '$1');
let str = '';
for (const [key, value] of Object.entries(data)) {
str += `--${boundary}\r\nContent-Disposition: form-data; name="${key}"\r\n\r\n${value}\r\n`;
}
return str;
}