With the Node JS request module it is possible to get the response, but, is there any way of getting the request headers sent?
I'm not sure what the official way of doing this is but there are several things that seem to work.
If you haven't bound the callback to another this value then it will just be the request, e.g.:
request.get(options, function() {
console.log(this.getHeader('... header name ...'));
console.log(this.headers);
});
You could also access the request using response.request:
request.get(options, function(err, response) {
console.log(response.request.getHeader('... header name ...'));
console.log(response.request.headers);
});
That second approach should work anywhere that you have access to the response.
I believe these are the relevant lines in the source code:
https://github.com/request/request/blob/253c5e507ddb95dd88622087b6387655bd0ff935/request.js#L940
https://github.com/request/request/blob/253c5e507ddb95dd88622087b6387655bd0ff935/request.js#L1314
Related
Let's say that I'm using a GET request on https://example.com and the response is this:
This is a response message.
How would I modify it in a way so that in my code, so that it can change the response to say something like this:
This is a MODIFIED response message.
For example, if my Electron app were to navigate to https://example.com, the screen would show me the modified content instead of the original content.
Essentially, I am trying to literally modify the request.
I have based my code off of this question but it only shows a proof of concept with a pre-typed Buffer, as in my situation I'd like modify the response instead of outright replacing it. So, my code looks like this:
protocol.interceptBufferProtocol("http", (req, CALLBACK) => {
if(req.url.includes("special url here")) {
var request = net.request({
method: req.method,
headers: req.headers,
url: req.url
});
request.on("response", (rp) => {
var d = [];
rp.on("data", c => d.push(c));
rp.on("end", () => {
var e = Buffer.concat(d);
console.log(e.toString());
// do SOMETHING with 'e', the response, then callback it.
CALLBACK(e);
});
});
request.end();
} else {
// Is supposedly going to carry out the request without interception
protocol.uninterceptProtocol("http");
}
}
This is supposed to manually request the URL, grab the response and return it. Without the protocol event, it works and gives me a response, but after some debugging, this piece of code consistently calls the same URL over and over with no response.
There is also the WebRequest API, but there is no way of modifying the response body, you can only modify the request headers & related content.
I haven't looked fully into Chromium-based solutions, but after looking at this, I'm not sure if it is possible to modify the response so it appears on my app's end in the first place. Additionally, I'm not familiar with the Chromium/Puppeteer messages that get sent all over the place.
Is there an elegant way to have Electron to get a URL response/request, call the URL using the headers/body/etc., then save & modify the response to appear different in Electron?
I started to write some tests for my application and I have issues to read/get response from the server. I tried many things but nothing really worked, can someone help me please ?
// /api/checkCreds
exports.checkCreds = async function(req, res){
//validation
if(!await User.checkCreds(req.body.username, req.body.password)){
var result = {error: true, data: "Incorrect"}
res.sendStatus = 401;
return res.send(JSON.stringify(result));
}
If credentials sent to the server aren't matching, return a response with "Incorrect" message back to the user.
In the test I'm trying to get data from the server to check if properties are matching the expected output.
//test.js
it("We should fail with HTTP code 401 because incorrect data is passed (username='incorrect' password='incorrect')", function(done){
supertest(app)
.post('/api/checkCreds')
.send({username: 'incorrect', password: 'incorrect'})
.expect({error: true, data: "Incorrect"})
.expect(401, done);
});
When ran, test fails because expected properties are different from the response sent by the server, which is an empty object {}.
Any help is appreciated.
You may try changing your first expect to see if you can coax supertest into showing you the actual body that it's comparing to. For example, expect('')
If that doesn't work, there's a version of expect that accepts a function. In that function, you should be able to print out what you are getting in the response body, ie. console.log(res).
It may be that there's some confusion with the JSON return type-- I haven't used that directly. You could try expecting JSON.
Finally, there's a strange paragraph in the documentation that I don't think applies, but I thought I'd mention:
One thing to note with the above statement is that superagent now sends any HTTP error (anything other than a 2XX response code) to the callback as the first argument if you do not add a status code expect (i.e. .expect(302)).
While trying to fix my issue, I noticed that in the HTTP response, Content-Type header was set to text/plain and my server was returning JSON, so that probably was the thing that confused supertest.
I think that res.send() sets the header to text/plain by default and I had to manually set the header value to application/json by using res.type('json'). At that point I was able to read the response body without an issue.
I also learned that res.json() sets the Content-Type header to application/json by default, so you don't need to do it manually like with res.send().
Working code:
// /api/checkCreds
if(!await User.checkCreds(req.body.username, req.body.password)){
var result = {error: true, data: "Incorrect"}
return res.status(401).json(result);
}
//test.js
it("We should fail with HTTP code 401 because incorrect data is passed (username='incorrect' password='incorrect')", function(done){
supertest(app)
.post('/api/checkCreds')
.set('Content-type', 'application/json')
.send({username: 'incorrect', password: 'incorrect'})
.expect(401)
.expect(function(res){
console.log(res.body);
})
.end(done);
});
Feel free to correct me if I stated something that isn't quite right.
Нello! I am looking to call a function which has been passed to an expressRouter.post(...) call.
This expressRouter.post(...) call is occurring in a file which I am unable to modify. The code has already been distributed to many clients and there is no procedure for me to modify their versions of the file. While I have no ability to update this file for remote clients, other developers are able to. I therefore face the issue of this POST endpoint's behaviour changing in the future.
I am also dealing with performance concerns. This POST endpoint expects req.body to be a parsed JSON object, and that JSON object can be excessively large.
My goal is to write a GET endpoint which internally activates this POST endpoint. The GET endpoint will need to call the POST endpoint with a very large JSON value, which has had URL query params inserted into it. The GET's functionality should always mirror the POST's functionality, including if the POST's functionality is updated in the future. For this reason I cannot copy/paste the POST's logic. Note also that the JSON format will never change.
I understand that the issue of calling an expressjs endpoint internally has conventionally been solved by either 1) extracting the router function into an accessible scope, or 2) generating an HTTP request to localhost.
Unfortunately in my case neither of these options are viable:
I can't move the function into an accessible scope as I can't modify the source, nor can I copy-paste the function as the original version may change
Avoiding the HTTP request is a high priority due to performance considerations. The HTTP request will require serializing+deserializing an excessively large JSON body, re-visiting a number of authentication middlewares (which require waiting for further HTTP requests + database queries to complete), etc
Here is my (contrived) POST endpoint:
expressRouter.post('/my/post/endpoint', (req, res) => {
if (!req.body.hasOwnProperty('val'))
return res.status(400).send('Missing "val"');
return res.status(200).send(`Your val: ${req.body.val}`);
});
If I make a POST request to localhost:<port>/my/post/endpoint I get the expected error or response based on whether I included "val" in the JSON body.
Now, I want to have exactly the same functionality available, but via GET, and with "val" supplied in the URL instead of in any JSON body. I have attempted the following:
expressRouter.get('/my/get/endpoint/:val', (req, res) => {
// Make it seem as if "val" occurred inside the JSON body
let fakeReq = {
body: {
val: req.params.val
}
};
// Now call the POST endpoint
// Pass the fake request, and the real response
// This should enable the POST endpoint to write data to the
// response, and it will seem like THIS endpoint wrote to the
// response.
manuallyCallExpressEndpoint(expressRouter, 'POST', '/my/post/endpoint', fakeReq, res);
});
Unfortunately I don't know how to implement manuallyCallExpressEndpoint.
Is there a solution to this problem which excludes both extracting the function into an accessible scope, and generating an HTTP request?
This seems possible, but it may make more sense to modify req and pass it, rather than create a whole new fakeReq object. The thing which enables this looks to be the router.handle(req, res, next) function. I'm not sure this is the smartest way to go about this, but it will certainly avoid the large overhead of a separate http request!
app.get('/my/get/endpoint/:val', (req, res) => {
// Modify `req`, don't create a whole new `fakeReq`
req.body = {
val: req.params.val
};
manuallyCallExpressEndpoint(app, 'POST', '/my/post/endpoint', req, res);
});
let manuallyCallExpressEndpoint = (router, method, url, req, res) => {
req.method = method;
req.url = url;
router.handle(req, res, () => {});
};
How about a simple middleware?
function checkVal(req, res, next) {
const val = req.params.val || req.body.val
if (!val) {
return res.status(400).send('Missing "val"');
}
return res.status(200).send(`Your val: ${val}`);
}
app.get('/my/get/endpoint/:val', checkVal)
app.post('/my/post/endpoint', checkVal)
This code isn't tested but gives you rough idea on how you can have the same code run in both places.
The checkVal function serves as a Express handler, with request, response and next. It checks for params first then the body.
I want to send form data which is coming from my angularjs form to nodejs and then I want to send these data from nodejs to my service API. But the data is not receiving at my service API. I cannot understand what was going wrong in this. Please help me to overcome this problem.
requestMethodDelete: function (url, form_data, header) {
return new Promise((resolve, reject) => {
console.log("FORM DATA IN DELETE REQUESST METHOD");
console.log(form_data);
//SET ALL THESE PARATMETER TO MAKE REQUEST
request.delete({url: url, form: form_data, headers: header},
function (error, response, body) {
resolve(body);
}
});
});
},
I want to send form data and header but couldn't receive at service API, please tell me what can I do for my expected result.
In request.delete function form option is not work for sending form_data. To sending form-data to our service api we need to use qs option rather than form option. that's it, it solved your problem also if you are facing the same problem which I was facing.
I am using request npm module in my app, to make to create a http client, as this.
var request = require('request');
And each time, I make a request to some server, I pass the options as below:
var options = {
url: "whateverurl...",
body: { some json data for POST ... }
}
request(options, cb(e, r, body) {
// handle response here...
})
This was working fine, until I started testing with high load, and I started getting errors indicating no address available (EADDRNOTAVAIL). It looks like I am running out of ephemeral ports, as there is no pooling or keep-alive enabled.
After that, I changed it to this:
var options = {
url: "whateverurl...",
body: { some json data for POST ... },
forever: true
}
request(options, cb(e, r, body) {
// handle response here...
})
(Note the option (forever:true)
I tried looking up request module's documentation about how to set keep-alive. According to the documentation and this stackoverflow thread, I am supposed to add {forever:true} to my options.
It didn't seem to work for me, because when I checked the tcpdump, the sever was still closing the connection. So, my question is:
Am I doing something wrong here?
Should I not be setting a global option to request module, while I am "require"ing it, instead of telling it to use {forever:true}, each time I make a http request? This is confusing to me.