feat: support wildcard on empty attributes

README.md

@@ -220,6 +220,14 @@ Very simple! Set `nonBooleanAttributes` to `[]`.
 nonBooleanAttributes: []
 ```
 
+#### "What if I want to delete all empty attributes?"
+
+Also very simple! Set `nonBooleanAttributes` to `['*']`.
+
+```js
+nonBooleanAttributes: ['*']
+```
+
 #### "What if I don't want to allow *any* tags?"
 
 Also simple!  Set `allowedTags` to `[]` and `allowedAttributes` to `{}`.

index.js

@@ -293,7 +293,7 @@ function sanitizeHtml(html, options, _recursing) {
           }
           // If the value is empty, and this is a known non-boolean attribute, delete it
           // List taken from https://html.spec.whatwg.org/multipage/indices.html#attributes-3
-          if (value === '' && options.nonBooleanAttributes.includes(a)) {
+          if (value === '' && (options.nonBooleanAttributes.includes(a) || options.nonBooleanAttributes.includes('*'))) {
             delete frame.attribs[a];
             return;
           }

test/test.js

@@ -1593,4 +1593,13 @@ describe('sanitizeHtml', function() {
       }
     }), '<input checked type="checkbox" />');
   });
+  it('should remove boolean attributes that are empty when wildcard * passed in', function() {
+    assert.equal(sanitizeHtml('<input checked form type="checkbox" />', {
+      allowedTags: 'input',
+      allowedAttributes: {
+        input: [ 'checked', 'form', 'type' ]
+      },
+      nonBooleanAttributes: [ '*' ]
+    }), '<input type="checkbox" />');
+  });
 });