unit.js

"use strict";

QUnit.module( "mousewheel" );

function makeWheelEvent( deltaX, deltaY ) {
	var event = window.document.createEvent( "Event" );
	event.initEvent( "wheel", true, true );
	event.deltaX = deltaX;
	event.deltaY = deltaY;
	event.deltaMode = 0;
	return event;
}

QUnit.test( ".on() and .trigger()", function( assert ) {
	assert.expect( 1 );

	var markup = jQuery( "<div>wheelme</div>" ).appendTo( "body" );

	markup.on( "mousewheel", function( e ) {
		assert.ok( true, "triggered a mousewheel event on " + e.target.innerText );
	} );
	markup.trigger( "mousewheel" );

	markup.remove();
} );

QUnit.test( "natively triggered events", function( assert ) {
	assert.expect( 6 );

	var markup = jQuery( "<p>wheelme</p>" ).appendTo( "body" );

	markup.on( "mousewheel", function( e ) {
		assert.ok( true, "triggered a mousewheel event on " + e.target.innerText );
		assert.ok( "deltaX" in e, "got a deltaX in the event" );
		assert.ok( !isNaN( parseFloat( e.deltaY ) ), "deltaY is a number: " + e.deltaY );
	} );

	// First wheel event "calibrates" so we won't measure this one
	var event1 = makeWheelEvent( 0, 2.2 );
	markup[ 0 ].dispatchEvent( event1 );

	var event2 = makeWheelEvent( 0, 10.528 );
	markup[ 0 ].dispatchEvent( event2 );

	markup.remove();
} );

QUnit.test( "mouse event properties are passed through", function( assert ) {
	assert.expect( 4 );

	var markup = jQuery( "<p>wheelme</p>" ).appendTo( "body" );

	markup.on( "mousewheel", function( e ) {
		var org = e.originalEvent;
		assert.equal( org.clientX, 342, "original event has clientX: " + org.clientX );
		assert.equal( org.clientY, 301, "original event has clientY: " + org.clientY );
		assert.ok( e.offsetX < org.clientX, "got plausible offsetX in the event: " + e.offsetX );
		assert.ok( e.offsetY < org.clientY, "got plausible offsetY in the event: " + e.offsetY );
	} );

	// Not sure why this property is manipulating offsetX/Y but the behavior cannot
	// change in a minor version so it will stay since it's set to true right now.
	// For testing we just want to ensure that the properties get through.
	var event1 = makeWheelEvent( 0, 2.2 );
	event1.offsetX = 1;
	event1.offsetY = 2;
	event1.clientX = 342;
	event1.clientY = 301;
	markup[ 0 ].dispatchEvent( event1 );

	markup.remove();
} );