Event: improve originalEvent hack

Ref 6df669f0fb87cd9975a18bf6bbe3c3548afa4fee
Ref gh-2336

src/event.js

@@ -648,17 +648,22 @@ jQuery.event = {
 		}
 	},
 
+	// Piggyback on a donor event to simulate a different one
 	simulate: function( type, elem, event, bubble ) {
-		// Piggyback on a donor event to simulate a different one.
-		// Fake originalEvent to avoid donor's stopPropagation, but if the
-		// simulated event prevents default then we do the same on the donor.
 		var e = jQuery.extend(
 			new jQuery.Event(),
 			event,
 			{
 				type: type,
-				isSimulated: true,
-				originalEvent: {}
+				isSimulated: true
+				// Previously, `originalEvent: {}` was set here, so stopPropagation call
+				// would not be triggered on donor event, since in our own
+				// jQuery.event.stopPropagation function we had a check for existence of
+				// originalEvent.stopPropagation method, so, consequently it would be a noop.
+				//
+				// Guard for simulated events was moved to jQuery.event.stopPropagation function
+				// since `originalEvent` should point to the original event for the
+				// constancy with other events and for more focused logic
 			}
 		);
 		if ( bubble ) {
@@ -763,7 +768,8 @@ jQuery.Event.prototype = {
 		var e = this.originalEvent;
 
 		this.isPropagationStopped = returnTrue;
-		if ( !e ) {
+
+		if ( !e || this.isSimulated ) {
 			return;
 		}
 		// If stopPropagation exists, run it on the original event

test/unit/event.js

@@ -2686,6 +2686,135 @@ test( "Inline event result is returned (#13993)", function() {
 	equal( result, 42, "inline handler returned value" );
 });
 
+test( "preventDefault() on focusin does not throw exception", function( assert ) {
+	expect( 1 );
+
+	var done = assert.async(),
+		input = jQuery( "<input/>" ).appendTo( "#form" );
+
+	input.on( "focusin", function( event ) {
+		var exceptionCaught;
+
+		try {
+			event.preventDefault();
+		} catch ( theException ) {
+			exceptionCaught = theException;
+		}
+
+		assert.strictEqual( exceptionCaught, undefined,
+			"Preventing default on focusin throws no exception" );
+
+		done();
+	} ).trigger( "focus" );
+} );
+
+test( "Donor event interference", function( assert ) {
+	assert.expect( 10 );
+
+	var html = "<div id='donor-outer'>" +
+		"<form id='donor-form'>" +
+			"<input id='donor-input' type='radio' />" +
+		"</form>" +
+	"</div>";
+
+	jQuery( "#qunit-fixture" ).append( html );
+
+	jQuery( "#donor-outer" ).on( "click", function( event ) {
+		assert.ok( true, "click bubbled to outer div" );
+		assert.equal( typeof event.originalEvent, "object", "make sure originalEvent exist" );
+		assert.equal( event.type, "click", "make sure event type is correct" );
+	} );
+	jQuery( "#donor-input" ).on( "click", function( event ) {
+		assert.ok( true, "got a click event from the input" );
+		assert.ok( !event.isPropagationStopped(), "propagation says it's not stopped" );
+		assert.equal( event.type, "click", "make sure event type is correct" );
+		assert.equal( typeof event.originalEvent, "object", "make sure originalEvent exist" );
+	} );
+	jQuery( "#donor-input" ).on( "change", function( event ) {
+		assert.equal( typeof event.originalEvent, "object", "make sure originalEvent exist" );
+		assert.equal( event.type, "change", "make sure event type is correct" );
+		assert.ok( true, "got a change event from the input" );
+		event.stopPropagation();
+	} );
+
+	jQuery( "#donor-input" )[ 0 ].click();
+} );
+
+test( "originalEvent property for IE8", function( assert ) {
+	if ( !(/msie 8\.0/i.test( window.navigator.userAgent )) ) {
+		assert.expect( 1 );
+		assert.ok( true, "Assertions should run only in IE" );
+		return;
+	}
+
+	assert.expect( 12 );
+
+	var html = "<div id='donor-outer'>" +
+		"<form id='donor-form'>" +
+			"<input id='donor-input' type='radio' />" +
+		"</form>" +
+	"</div>";
+
+	jQuery( "#qunit-fixture" ).append( html );
+
+	jQuery( "#donor-outer" ).on( "change", function( event ) {
+		assert.ok( true, "click bubbled to outer div" );
+		assert.equal( event.originalEvent.type, "click", "make sure simulated event is a click" );
+		assert.equal( event.type, "change", "make sure event type is correct" );
+	} );
+
+	jQuery( "#donor-outer" ).on( "click", function( event ) {
+		assert.ok( true, "click bubbled to outer div" );
+		assert.equal( event.originalEvent.type, "click", "make sure originalEvent exist" );
+	} );
+	jQuery( "#donor-input" ).on( "click", function( event ) {
+		assert.ok( true, "got a click event from the input" );
+		assert.ok( !event.isPropagationStopped(), "propagation says it's not stopped" );
+		assert.equal( event.originalEvent.type, "click", "make sure originalEvent exist" );
+		assert.equal( event.type, "click", "make sure event type is correct" );
+	} );
+	jQuery( "#donor-input" ).on( "change", function( event ) {
+		assert.equal( event.originalEvent.type, "click", "make sure originalEvent exist" );
+		assert.equal( event.type, "change", "make sure event type is correct" );
+		assert.ok( true, "got a change event from the input" );
+	} );
+
+	jQuery( "#donor-input" )[ 0 ].click();
+} );
+
+test( "originalEvent property for Chrome, Safari and FF of simulated event", function( assert ) {
+	var userAgent = window.navigator.userAgent;
+
+	if ( !(/chrome/i.test( userAgent ) ||
+	       /firefox/i.test( userAgent ) ||
+	       /safari/i.test( userAgent ) ) ) {
+		assert.expect( 1 );
+		assert.ok( true, "Assertions should run only in Chrome, Safari and FF" );
+		return;
+	}
+
+	assert.expect( 4 );
+
+	var html = "<div id='donor-outer'>" +
+		"<form id='donor-form'>" +
+			"<input id='donor-input' type='radio' />" +
+		"</form>" +
+	"</div>";
+
+	jQuery( "#qunit-fixture" ).append( html );
+
+	jQuery( "#donor-outer" ).on( "focusin", function( event ) {
+		assert.ok( true, "focusin bubbled to outer div" );
+		assert.equal( event.originalEvent.type, "focus",
+		             "make sure originalEvent type is correct" );
+		assert.equal( event.type, "focusin", "make sure type is correct" );
+	} );
+	jQuery( "#donor-input" ).on( "focus", function() {
+		assert.ok( true, "got a focus event from the input" );
+	} );
+	jQuery( "#donor-input" ).trigger( "focus" );
+} );
+
 // This tests are unreliable in Firefox
 if ( !(/firefox/i.test( window.navigator.userAgent )) ) {
 	test( "Check order of focusin/focusout events", 2, function() {