Core https library vs. npm 'request' library - node.js

Question

I am running into a very strange issue when trying to use the built-in node https library.
Request Headers:
let requestDetails = {
hostname: 'api.domain.com',
method: 'POST',
path: '/endpointIWant/goHere
headers: {
'Client-ID': clientId,
'Content-Type': 'application/json',
Authorization: bearerToken
},
};
Request body:
let body = JSON.stringify({
"content_type": "application/json",
"message" : message
});
This is my standard call using the default https library of node:
let req = https.request(requestDetails, function (res){
let responseBody = undefined;
res.on('body', function(res) {
responseBody = '';
});
res.on('data', function(chunk) {
responseBody += chunk;
});
res.on('end', function() {
console.log(responseBody);
});
});
req.write(body);
req.on('error', function(e) {
console.log(e);
});
req.end();
Now whenever I send this request to the relevant server I get a:
Your browser sent a request that this server could not understand.
Reference #7.24507368.1554749705.3185b29b
However when I use the popular 'request' library on NPM it works fine and I get the response I expect.
This leads be to believe there is something different in maybe the 'encoding' or 'chunking' of the requests between these two libraries, but I cannot figure out what.
Does anyone have experience with the Node https library and understand any gotcha's there?
I prefer to use built-in libraries as much as possible to keep my package size low.

Answer 1

When using native http or https modules, you need to use the querystring module to stringify your body.
const querystring = require('querystring');
let body = querystring.stringify({
"content_type": "application/json",
"message" : message
});
//also include the content length of your body as a header
let requestDetails = {
hostname: 'api.domain.com',
method: 'POST',
path: '/endpointIWant/goHere
headers: {
'Client-ID': clientId,
'Content-Type': 'application/json',
'Content-Length' : body.length
Authorization: bearerToken
},
};
'request' is built on top of the native modules and does this internally when you pass it a json body