Add support for HTML input event (aka oninput) on text fields.

The input event is like onchange, but on text fields, it is fired as soon as the value of the field changes, not when the field is blurred. It is a more appropriate event than 'keydown' or 'keyup', which behave unpredictably with paste events, held-down keys, etc.

Support is a little problematic, but it is supported well by Webkit and Firefox, so it seems useful to add here.

spec/driver_spec.rb

@@ -659,6 +659,7 @@
                 element.addEventListener("keydown", recordEvent);
                 element.addEventListener("keypress", recordEvent);
                 element.addEventListener("keyup", recordEvent);
+                element.addEventListener("input", recordEvent);
                 element.addEventListener("change", recordEvent);
                 element.addEventListener("blur", recordEvent);
                 element.addEventListener("mousedown", recordEvent);
@@ -678,7 +679,7 @@
 
     let(:keyevents) do
       (%w{focus} +
-       newtext.length.times.collect { %w{keydown keypress keyup} } +
+       newtext.length.times.collect { %w{keydown keypress keyup input} } +
        %w{change blur}).flatten
     end
 

src/capybara.js

@@ -176,6 +176,7 @@ Capybara = {
         this.trigger(index, "keydown");
         this.keypress(index, false, false, false, false, 0, value.charCodeAt(strindex));
         this.trigger(index, "keyup");
+        this.trigger(index, "input");
       }
       this.trigger(index, "change");
       this.trigger(index, "blur");