Leaving out default value, and checking for definition instead of null value in the filtering logic

Author: gmovr

packages/block-library/src/table-of-contents/block.json

@@ -21,8 +21,7 @@
 			"default": false
 		},
 		"maxLevel": {
-			"type": [ "number", "null" ],
-			"default": null
+			"type": "number"
 		}
 	},
 	"supports": {

packages/block-library/src/table-of-contents/hooks.js

@@ -102,7 +102,7 @@ function getLatestHeadings( select, clientId ) {
 				const headingAttributes = getBlockAttributes( blockClientId );
 
 				// Skip headings that are deeper than maxLevel
-				if ( maxLevel !== null && headingAttributes.level > maxLevel ) {
+				if ( maxLevel && headingAttributes.level > maxLevel ) {
 					continue;
 				}