Core: detect incorrectly nested elements

dmethvin · dmethvin · commit f00ab1924c63 · 2020-04-10T20:02:58.000-04:00
diff --git a/src/core.js b/src/core.js
@@ -3,13 +3,16 @@ var oldInit = jQuery.fn.init,
 	oldFind = jQuery.find,
 	rattrHashTest = /\[(\s*[-\w]+\s*)([~|^$*]?=)\s*([-\w#]*?#[-\w#]*)\s*\]/,
 	rattrHashGlob = /\[(\s*[-\w]+\s*)([~|^$*]?=)\s*([-\w#]*?#[-\w#]*)\s*\]/g,
+	rxhtmlTag = /<(?!area|br|col|embed|hr|img|input|link|meta|param)(([a-z][^\/\0>\x20\t\r\n\f]*)[^>]*)\/>/gi,
+	rsingleTag = ( /^<([a-z][^\/\0>:\x20\t\r\n\f]*)[\x20\t\r\n\f]*\/?>(?:<\/\1>|)$/i ),
 
 	// Support: Android <=4.0 only
 	// Make sure we trim BOM and NBSP
 	rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
 
 jQuery.fn.init = function( arg1 ) {
-	var args = Array.prototype.slice.call( arguments );
+	var args = Array.prototype.slice.call( arguments ),
+		changed;
 
 	if ( typeof arg1 === "string" && arg1 === "#" ) {
 
@@ -18,6 +21,15 @@ jQuery.fn.init = function( arg1 ) {
 		args[ 0 ] = [];
 	}
 
+	if ( typeof arg1 === "string" && arg1.trim().charAt( 0 ) === "<" ) {
+		if ( !rsingleTag.test( arg1 ) ) {
+		changed = arg1.replace( rxhtmlTag, "<$1></$2>" );
+		if ( changed !== arg1 ) {
+			migrateWarn( "HTML tags must be properly nested and closed: " + arg1 );
+		}
+	}
+	}
+
 	return oldInit.apply( this, args );
 };
 jQuery.fn.init.prototype = jQuery.fn;
diff --git a/test/core.js b/test/core.js
@@ -65,6 +65,29 @@ QUnit.test( "jQuery( '#' )", function( assert ) {
 	} );
 } );
 
+QUnit.test( "Improperly closed elements", function( assert ) {
+	assert.expect( 3 );
+
+	expectWarning( assert, "Elements not self-closable nested wrong", 3, function() {
+		jQuery( "<div><p/><span/></div>" );
+		jQuery( "<blockquote><p class='bad' /><span/></blockquote>" );
+		jQuery( "<div data-borked='y'><span/> <p/></div>" );
+	} );
+
+	expectWarning( assert, "Elements not self-closable", 3, function() {
+		jQuery( "<div class=wonky />" );
+		jQuery( "<p style='width: 2%' />" );
+		jQuery( "<span aria-label='hello' />" );
+	} );
+
+	expectNoWarning( assert, "Bare elements", function() {
+		jQuery( "<p/>" );
+		jQuery( "<abbr />" );
+		jQuery( "<head />" );
+	} );
+
+} );
+
 QUnit.test( "Attribute selectors with unquoted hashes", function( assert ) {
 	assert.expect( 31 );
 
