Pass error from requests in Node to callback

lib/node/request.js

@@ -49,8 +49,8 @@ class Request {
       this.onload();
     });
 
-    req.on("error", () => {
-      this.onerror();
+    req.on("error", (err) => {
+      this.onerror(err);
     });
 
     if (body instanceof Readable) {

test/spec/helpers/node/ajax.js

@@ -48,6 +48,10 @@ class MockRequest {
     this._req.emit("response", res);
   }
 
+  responseError(err) {
+    this._req.emit("error", err);
+  }
+
   contentType() {
     return this.requestHeaders["Content-Type"] || "";
   }

test/spec/upload.node.js

@@ -82,6 +82,30 @@ describe("tus", function () {
 
       expectHelloWorldUpload(file, options, done);
     });
+
+    it("should pass through errors from the request", function () {
+      var resErr = new Error("something bad, really!");
+      var buffer = new Buffer("hello world");
+      var option = {
+        endpoint: "/uploads",
+        onError: function (err) {
+          expect(err.causingError).toBe(resErr);
+        }
+      };
+
+      spyOn(option, "onError").and.callThrough();
+
+      var upload = new tus.Upload(buffer, option);
+      upload.start();
+
+      var req = jasmine.Ajax.requests.mostRecent();
+      expect(req.url).toBe("/uploads");
+      expect(req.method).toBe("POST");
+
+      req.responseError(resErr);
+
+      expect(option.onError).toHaveBeenCalled();
+    });
   });
 });