I am currently developing a Node.js/express application in typescript that involves a proxy route with specialized business logic for determining the proxy URL:
import proxy from "http-proxy-middleware";
const controller = diContainer.get<IController>(TYPES.Controller);
const app = express();
app.use("/customProxy", controller.handleProxy());
@injectable()
export class Controller implements IController {
public handleProxy(): RequestHandler {
return proxy(
"**", // proxy all incoming routes
{
router: (req: Request) => {
// custom logic to translate route
return customRouteBasedOnIncomingRequest;
},
onProxyRes: (proxyRes: http.IncomingMessage, req: http.IncomingMessage, res: http.ServerResponse) => {
// custom logic to set outgoing response
res.setHeader("custom", "header")
},
}
});
}
}
I have been exploring the possibility of using mock-express-request to simulate Request/Response objects. However, I am uncertain how to integrate it with the proxy.
Is there a method to inject a mock that can intercept the http client sending the proxy request? Ideally, I would like to incorporate this function into the Controller:
public mockedHttpServer(req: Request):Response
{
const res = new MockExrpessResponse();
if (req.url == "http://expected.url"){
res.write("success");
res.statuscode = 200;
}
else{
res.statuscode = 404;
}
return res;
}
I attempted to intervene with proxy.onProxyReq and utilize proxyReq.abort(), followed by writing directly to the Response. Unfortunately, this approach did not prevent an actual request from being sent out.
Are there any alternative methods to tap into the http stack and mimic the network io operations?