Merge pull request #33 from pmu-tech/feature_handle-cookie-and-body-f…

…or-proxy

Fix Set-Cookie header and request body

src/fixRequestBody.test.ts

@@ -0,0 +1,63 @@
+import express from 'express';
+import http from 'http';
+
+import { fixRequestBody } from './fixRequestBody';
+
+const fakeProxyRequest = () => {
+  const proxyRequest = new http.ClientRequest('http://some-host');
+  proxyRequest.emit = () => false; // Otherwise we get "Error: getaddrinfo ENOTFOUND some-host"
+
+  return proxyRequest;
+};
+
+test('should not write when body is undefined', () => {
+  const proxyRequest = fakeProxyRequest();
+
+  jest.spyOn(proxyRequest, 'setHeader');
+  jest.spyOn(proxyRequest, 'write');
+
+  fixRequestBody(proxyRequest, { body: undefined } as express.Request);
+
+  expect(proxyRequest.setHeader).not.toHaveBeenCalled();
+  expect(proxyRequest.write).not.toHaveBeenCalled();
+});
+
+test('should not write when body is empty', () => {
+  const proxyRequest = fakeProxyRequest();
+
+  jest.spyOn(proxyRequest, 'setHeader');
+  jest.spyOn(proxyRequest, 'write');
+
+  fixRequestBody(proxyRequest, { body: {} } as express.Request);
+
+  expect(proxyRequest.setHeader).not.toHaveBeenCalled();
+  expect(proxyRequest.write).not.toHaveBeenCalled();
+});
+
+test('should write when body is not empty and Content-Type is application/json', () => {
+  const proxyRequest = fakeProxyRequest();
+  proxyRequest.setHeader('content-type', 'application/json; charset=utf-8');
+
+  jest.spyOn(proxyRequest, 'setHeader');
+  jest.spyOn(proxyRequest, 'write');
+
+  fixRequestBody(proxyRequest, { body: { someField: 'some value' } } as express.Request);
+
+  const expectedBody = JSON.stringify({ someField: 'some value' });
+  expect(proxyRequest.setHeader).toHaveBeenCalledWith('Content-Length', expectedBody.length);
+  expect(proxyRequest.write).toHaveBeenCalledWith(expectedBody);
+});
+
+test('should write when body is not empty and Content-Type is application/x-www-form-urlencoded', () => {
+  const proxyRequest = fakeProxyRequest();
+  proxyRequest.setHeader('content-type', 'application/x-www-form-urlencoded');
+
+  jest.spyOn(proxyRequest, 'setHeader');
+  jest.spyOn(proxyRequest, 'write');
+
+  fixRequestBody(proxyRequest, { body: { someField: 'some value' } } as express.Request);
+
+  const expectedBody = 'someField=some+value';
+  expect(proxyRequest.setHeader).toHaveBeenCalledWith('Content-Length', expectedBody.length);
+  expect(proxyRequest.write).toHaveBeenCalledWith(expectedBody);
+});

src/fixRequestBody.ts

@@ -0,0 +1,33 @@
+import http from 'http';
+
+/**
+ * Fix proxied body if bodyParser is involved.
+ *
+ * @see https://github.com/chimurai/http-proxy-middleware/blob/v2.0.1/src/handlers/fix-request-body.ts
+ * @see https://github.com/chimurai/http-proxy-middleware/issues/320
+ * @see https://github.com/chimurai/http-proxy-middleware/pull/492
+ */
+const fixRequestBody = (proxyReq: http.ClientRequest, req: http.IncomingMessage) => {
+  const requestBody = (req as unknown as Request).body;
+
+  if (!requestBody || Object.keys(requestBody).length === 0) {
+    return;
+  }
+
+  const contentType = proxyReq.getHeader('Content-Type') as string;
+  const writeBody = (bodyData: string) => {
+    // deepcode ignore ContentLengthInCode: bodyParser fix
+    proxyReq.setHeader('Content-Length', Buffer.byteLength(bodyData));
+    proxyReq.write(bodyData);
+  };
+
+  if (contentType && contentType.includes('application/json')) {
+    writeBody(JSON.stringify(requestBody));
+  }
+
+  if (contentType === 'application/x-www-form-urlencoded') {
+    writeBody(new URLSearchParams(requestBody as unknown as string).toString());
+  }
+};
+
+export { fixRequestBody };

src/proxy.ts

@@ -1,9 +1,10 @@
 import express from 'express';
 import { createProxyServer } from 'http-proxy';
 
-const proxy = createProxyServer({ changeOrigin: true });
+import { fixRequestBody } from './fixRequestBody';
+import { removeSecureFromSetCookie } from './removeSecureFromSetCookie';
 
-export const send = (
+const send = (
   target: string,
   req: express.Request,
   res: express.Response,
@@ -19,5 +20,15 @@ export const send = (
   //
   // [Proxy with express.js](https://stackoverflow.com/q/10435407)
 
+  const proxy = createProxyServer({
+    // Explanations: https://github.com/http-party/node-http-proxy/pull/1130
+    changeOrigin: true,
+    cookieDomainRewrite: req.hostname
+  });
+
+  proxy.on('proxyReq', fixRequestBody);
+  proxy.on('proxyRes', removeSecureFromSetCookie);
   proxy.web(req, res, { target }, next);
 };
+
+export { send };

src/removeSecureFromSetCookie.test.ts

@@ -0,0 +1,31 @@
+import { removeSecureFromSetCookie } from './removeSecureFromSetCookie';
+
+test('should remove Secure attribute from Set-Cookie header', () => {
+  const proxyRes = {
+    headers: {
+      'set-cookie': [
+        'cookie1=ZYADVSQYTDZA1; Secure; SameSite',
+        'cookie2=ZYADVSQYTDZA2; Secure',
+        'cookie3=ZYADVSQYTDZA3'
+      ]
+    }
+  };
+
+  removeSecureFromSetCookie(proxyRes);
+
+  expect(proxyRes.headers['set-cookie']).toEqual([
+    'cookie1=ZYADVSQYTDZA1; SameSite',
+    'cookie2=ZYADVSQYTDZA2',
+    'cookie3=ZYADVSQYTDZA3'
+  ]);
+});
+
+test('do nothing if no Set-Cookie header', () => {
+  const proxyRes = {
+    headers: {}
+  };
+
+  removeSecureFromSetCookie(proxyRes);
+
+  expect(proxyRes.headers).toEqual({});
+});

src/removeSecureFromSetCookie.ts

@@ -0,0 +1,20 @@
+import http from 'http';
+
+/**
+ * http-proxy does not remove 'Secure' attribute from Set-Cookie header.
+ *
+ * @see https://github.com/http-party/node-http-proxy/issues/1165
+ * @see https://github.com/http-party/node-http-proxy/pull/1166
+ */
+const removeSecureFromSetCookie = (proxyRes: { headers: http.IncomingHttpHeaders }) => {
+  // ["Header names are lower-cased"](https://nodejs.org/dist/latest-v16.x/docs/api/http.html#messageheaders)
+
+  if (proxyRes.headers['set-cookie']) {
+    const cookies = proxyRes.headers['set-cookie'].map(cookie => cookie.replace(/; secure/gi, ''));
+    /* eslint-disable no-param-reassign */
+    proxyRes.headers['set-cookie'] = cookies;
+    /* eslint-enable no-param-reassign */
+  }
+};
+
+export { removeSecureFromSetCookie };