Tabs: Rename ui-tab class to ui-tabs-tab for consistent prefixes

Fixes #12061
Closes jquerygh-1538
Ref #7053
Ref jquery/api.jqueryui.com#256

Author: jzaefferer

tests/unit/tabs/core.js

@@ -9,7 +9,7 @@ var state = testHelper.state;
 module( "tabs: core" );
 
 test( "markup structure", function( assert ) {
-	expect( 17 );
+	expect( 20 );
 	var element = $( "#tabs1" ).tabs(),
 		tabList = element.find( "ul, ol" ),
 		tabs = tabList.find( "li" ),
@@ -21,9 +21,15 @@ test( "markup structure", function( assert ) {
 	assert.lacksClasses( element, "ui-tabs-collapsible" );
 	assert.hasClasses( tabList, "ui-tabs-nav ui-widget-header" );
 	equal( tabList.length, 1, "The widget contains exactly one tab list" );
+	assert.hasClasses( tabs[ 0 ], "ui-tabs-tab" );
+	assert.hasClasses( tabs[ 1 ], "ui-tabs-tab" );
+	assert.hasClasses( tabs[ 2 ], "ui-tabs-tab" );
+
+	// DEPRECATED
 	assert.hasClasses( tabs[ 0 ], "ui-tab" );
 	assert.hasClasses( tabs[ 1 ], "ui-tab" );
 	assert.hasClasses( tabs[ 2 ], "ui-tab" );
+
 	equal( tabs.length, 3, "There are exactly three tabs" );
 	assert.hasClasses( anchors[ 0 ], "ui-tabs-anchor" );
 	assert.hasClasses( anchors[ 1 ], "ui-tabs-anchor" );

ui/tabs.js

@@ -32,7 +32,7 @@
 	}
 }( function( $ ) {
 
-return $.widget( "ui.tabs", {
+$.widget( "ui.tabs", {
 	version: "@VERSION",
 	delay: 300,
 	options: {
@@ -417,7 +417,7 @@ return $.widget( "ui.tabs", {
 				role: "tab",
 				tabIndex: -1
 			} );
-		this._addClass( this.tabs, "ui-tab", "ui-state-default" );
+		this._addClass( this.tabs, "ui-tabs-tab", "ui-state-default" );
 
 		this.anchors = this.tabs.map( function() {
 			return $( "a", this )[ 0 ];
@@ -880,4 +880,19 @@ return $.widget( "ui.tabs", {
 	}
 } );
 
+// DEPRECATED
+// TODO: Switch return back to widget declaration at top of file when this is removed
+if ( $.uiBackCompat !== false ) {
+
+	// Backcompat for ui-tab class (now ui-tabs-tab)
+	$.widget( "ui.tabs", $.ui.tabs, {
+		_processTabs: function() {
+			this._superApply( arguments );
+			this._addClass( this.tabs, "ui-tab" );
+		}
+	} );
+}
+
+return $.ui.tabs;
+
 } ) );