HEAD request not working on Edge

IncomingMessage から始めます。ここでは fetch のレスポンスボディが getReader() で読み取られます。Edge で HEAD リクエストを再現します。null のレスポンスボディをクラッシュやハングなしに処理し、ボディがあるレスポンスについては既存の動作を維持します。

When doing a HEAD request with the http library, the javascript just crashes and does not give me any answers.

I tried debugging it myself and found that the library uses fetch to fetch the head. The response of this message is given to IncomingMessage. IncomingMessage assumes that a response has a body. In the case of Edge, the body is just null, because a HEAD request has no body.

Nonetheless, this is accessed in anyway:

var reader = response.body.getReader()
		function read () {
			reader.read().then(function (result) {
				if (self._destroyed)
					return
				if (result.done) {
					self.push(null)
					return
				}
				self.push(new Buffer(result.value))
				read()
			}).catch(function(err) {
				self.emit('error', err)
			})
		}

And libraries crashes, causing the HEAD request to hang indefinitely.

To be able to use my own code I added a monkey fix, to temporarily make edge work:

window.fetch_old = window.fetch
window.fetch = function () {
    var result = window.fetch_old.apply(null, arguments);
    result.then_old = result.then;
    result.then = function (callback) {
        return result.then_old(function(response) {
            if(response.body === null){
                var body = { "getReader" : function () {
                 return {
                     "read" : function (){
                         return {
                             "then" : function (callback){
                                 callback({"done":true});
                                 return {"catch" : function(){}};
                             }
                         }
                     }
                 }   
                }};
                //override body....
                var handler = {
                    get: function(target, name) {
                        if(name === "body"){
                            return body;
                        }
                        return target[name];
                    }
                };
                var response_new = new Proxy(response, handler);
                return callback(response_new);
            }
            return callback(response);
        });
    }
    return result;
};

But obviously, it would be great if this could be fixed in the library, instead of my ugly hack.