Tests: Account for an extra noop focus/blur listener in jQuery >=3.4

tests/lib/qunit-assert-domequal.js

@@ -145,34 +145,35 @@ function extract( selector, message ) {
 // data comparisons in tests.
 // See https://github.com/jquery/jquery/issues/4496
 if ( result.events && jQueryVersionSince( "3.4.0" ) ) {
-var i, eventDataList, eventData;
 $.each( [ "focus", "blur" ], function( index, eventType ) {
 if ( !result.events[ eventType ] ) {
 return;
 }
 
-// Only the special internal handlers
-// have the namespace field set to boolean `false`;
-// filter them out.
-result.events[ eventType ] = result.events[ eventType ].filter( function( eventData ) {
-return eventData.namespace !== false;
-} );
-
-eventDataList = result.events[ eventType ];
-for ( i = eventDataList.length - 1; i > -1; i-- ) {
-eventData = eventDataList[ i ];
-
-// Only these special jQuery internal handlers
-// have the `namespace` field set to `false`;
-// all other events use a string value, possibly
-// an empty string if no namespace was set.
-if ( eventData.namespace === false ) {
-eventDataList.splice( i, 1 );
-}
-}
+// Filter special jQuery focus-related handlers out.
+result.events[ eventType ] = result.events[ eventType ]
+.filter( function( eventData ) {
+var handlerBody = eventData.handler.toString().replace(
+/^[^{]+\{[\s\n]*((?:.|\n)*?)\s*;?\s*\}[^}]*$/,
+"$1"
+);
+
+// Only these special jQuery internal handlers
+// have the `namespace` field set to `false`;
+// all other events use a string value, possibly
+// an empty string if no namespace was set.
+return eventData.namespace !== false &&
+
+// If a focus event was triggered without adding a handler first,
+// jQuery attaches an empty handler at the beginning of a trigger
+// call. Ignore this handler as well; it's a function with just
+// `return true;` in the body.
+// Handle the minified version as well.
+handlerBody !== "return true" && handlerBody !== "return!0";
+} );
 
 // Remove empty eventData collections to follow jQuery behavior.
-if ( !eventDataList.length ) {
+if ( !result.events[ eventType ].length ) {
 delete result.events[ eventType ];
 }
 } );