isRequired on attrs

packages/core/src/helpers/getAttributesFromExtensions.ts

@@ -24,6 +24,7 @@ export function getAttributesFromExtensions(extensions: Extensions): ExtensionAt
     renderHTML: null,
     parseHTML: null,
     keepOnSplit: true,
+    isRequired: false,
   }
 
   extensions.forEach(extension => {
@@ -87,14 +88,20 @@ export function getAttributesFromExtensions(extensions: Extensions): ExtensionAt
     Object
       .entries(attributes)
       .forEach(([name, attribute]) => {
+        const mergedAttr = {
+          ...defaultAttribute,
+          ...attribute,
+        }
+
+        if (attribute.isRequired && attribute.default === undefined) {
+          delete mergedAttr.default;
+        }
+  
         extensionAttributes.push({
           type: extension.name,
           name,
-          attribute: {
+          attribute: mergedAttr,
-            ...defaultAttribute,
+        });
-            ...attribute,
-          },
-        })
       })
   })
 

packages/core/src/types.ts

@@ -128,6 +128,7 @@ export type Attribute = {
   renderHTML?: ((attributes: Record<string, any>) => Record<string, any> | null) | null,
   parseHTML?: ((element: HTMLElement) => any | null) | null,
   keepOnSplit: boolean,
+  isRequired?: boolean,
 }
 
 export type Attributes = {