General: Further preserve back-compat for wp.sanitize.stripTags() to return empty string when falsy value supplied.

Developed in WordPress#10856

Follow-up to [61578], [61347], [60907].

Props jonsurrell, hugod, westonruter.
See #64274.
Fixes #64574.


git-svn-id: https://develop.svn.wordpress.org/trunk@61585 602fd350-edb4-49c9-b593-d223f7449a82

Author: westonruter

src/js/_enqueues/wp/sanitize.js

@@ -23,7 +23,7 @@
 		 * @return {string} Stripped text.
 		 */
 		stripTags: function( text ) {
-			if ( null === text || 'undefined' === typeof text ) {
+			if ( ! text ) {
 				return '';
 			}
 

tests/qunit/wp-includes/js/wp-sanitize.js

@@ -22,6 +22,31 @@ QUnit.test( 'stripTags should convert numbers to strings', function( assert ) {
 	assert.strictEqual( result, '123', 'stripTags( 123 ) should return "123"' );
 } );
 
+QUnit.test( 'stripTags should return empty string for input 0', function( assert ) {
+	const result = wp.sanitize.stripTags( 0 );
+	assert.strictEqual( result, '', 'stripTags( 0 ) should return ""' );
+} );
+
+QUnit.test( 'stripTags should return "0" for input "0"', function( assert ) {
+	const result = wp.sanitize.stripTags( '0' );
+	assert.strictEqual( result, '0', 'stripTags( "0" ) should return "0"' );
+} );
+
+QUnit.test( 'stripTags should return empty string for input false', function( assert ) {
+	const result = wp.sanitize.stripTags( false );
+	assert.strictEqual( result, '', 'stripTags( false ) should return ""' );
+} );
+
+QUnit.test( 'stripTags should return empty string for input NaN', function( assert ) {
+	const result = wp.sanitize.stripTags( NaN );
+	assert.strictEqual( result, '', 'stripTags( NaN ) should return ""' );
+} );
+
+QUnit.test( 'stripTags should return empty string for empty string input', function( assert ) {
+	const result = wp.sanitize.stripTags( '' );
+	assert.strictEqual( result, '', 'stripTags( "" ) should return ""' );
+} );
+
 QUnit.module( 'wp.sanitize.stripTagsAndEncodeText' );
 
 QUnit.test( 'stripTagsAndEncodeText should return empty string for null input', function( assert ) {