Required controller input validation

Given the following controller/controller.go:

package controller

type Controller struct {}

type User struct {
  Name string `json:"name"`
  Email string `json:"email"`
}

func (c *Controller) Create(name, email string) (*User, error) {
  return &User{name, email}, nil
}

If you run the following request: GET /?name=Alice, you'll get back the following response:

{
  "name": "Alice",
  "email": ""
}

It should actually be a validation error, "email cannot be blank", never run the controller action and most likely return a 422.

Start with controller/controller.go and reproduce the GET /?name=Alice request described in the issue. Trace how controller inputs reach Create and identify the existing request-handling or validation entry point. Done means a missing email produces "email cannot be blank", returns HTTP 422, and does not run the controller action.