All: Remove usage of jQuery positional selectors

jQuery positional selectors () have been deprecated in
[jQuery 3.4.0](https://blog.jquery.com/2019/04/10/jquery-3-4-0-released/)
and they'll be removed in jQuery 4.0.0. This PR removes their usage.

Most of the changes were possible without changing public API. However,
dropping `:even` usage required a change to the
[`header` option](https://api.jqueryui.com/accordion/#option-header)
of the accordion widget. I made it an optional function; this will need
to be documented.

The polyfill for `.even()` & `.odd()` is added for jQuery <3.5.0. There was
no usage of the :odd selector in the code but the `.odd()` method is also
polyfilled for completeness.

Closes gh-1904

1 files changed, 6 insertions, 6 deletions

diff --git a/tests/unit/menu/methods.js b/tests/unit/menu/methods.js
index 48eaa33cd..e0e942dd6 100644
--- a/tests/unit/menu/methods.js
+++ b/tests/unit/menu/methods.js
@@ -51,33 +51,33 @@ QUnit.test( "refresh", function( assert ) {
 	assert.equal( element.find( ".ui-menu-item" ).length, 5, "Incorrect number of menu items" );
 	element.append( "<li><a href='#'>test item</a></li>" ).menu( "refresh" );
 	assert.equal( element.find( ".ui-menu-item" ).length, 6, "Incorrect number of menu items" );
-	element.find( ".ui-menu-item:last" ).remove().end().menu( "refresh" );
+	element.find( ".ui-menu-item" ).last().remove().end().end().menu( "refresh" );
 	assert.equal( element.find( ".ui-menu-item" ).length, 5, "Incorrect number of menu items" );
 	element.append( "<li>---</li>" ).menu( "refresh" );
 	assert.equal( element.find( ".ui-menu-item" ).length, 5, "Incorrect number of menu items" );
-	element.children( ":last" ).remove().end().menu( "refresh" );
+	element.children().last().remove().end().end().menu( "refresh" );
 	assert.equal( element.find( ".ui-menu-item" ).length, 5, "Incorrect number of menu items" );
 } );
 
 QUnit.test( "refresh submenu", function( assert ) {
 	assert.expect( 2 );
 	var element = $( "#menu2" ).menu();
-	assert.equal( element.find( "ul:first .ui-menu-item" ).length, 3 );
+	assert.equal( element.find( "ul" ).first().find( ".ui-menu-item" ).length, 3 );
 	element.find( "ul" ).addBack().append( "<li><a href=\"#\">New Item</a></li>" );
 	element.menu( "refresh" );
-	assert.equal( element.find( "ul:first .ui-menu-item" ).length, 4 );
+	assert.equal( element.find( "ul" ).first().find( ".ui-menu-item" ).length, 4 );
 } );
 
 QUnit.test( "refresh icons (see #9377)", function( assert ) {
 	assert.expect( 3 );
 	var element = $( "#menu1" ).menu();
 	assert.lacksClasses( element, "ui-menu-icons" );
-	element.find( "li:first .ui-menu-item-wrapper" )
+	element.find( "li" ).first().find( ".ui-menu-item-wrapper" )
 		.html( "<span class='ui-icon ui-icon-disk'></span>Save</a>" );
 	element.menu( "refresh" );
 
 	assert.hasClasses( element, "ui-menu-icons" );
-	element.find( "li:first .ui-menu-item-wrapper" ).html( "Save" );
+	element.find( "li" ).first().find( ".ui-menu-item-wrapper" ).html( "Save" );
 	element.menu( "refresh" );
 	assert.lacksClasses( element, "ui-menu-icons" );
 } );