[popover] Make togglePopover throw more exceptions

https://bugs.webkit.org/show_bug.cgi?id=258574

Reviewed by Tim Nguyen.

Throw exceptions in togglePopover in case of a disconnected node or the popover
attribute not being set anymore, see whatwg/html#8999.

* LayoutTests/imported/w3c/web-platform-tests/html/semantics/popovers/togglePopover-expected.txt:
* LayoutTests/imported/w3c/web-platform-tests/html/semantics/popovers/togglePopover.html:
* Source/WebCore/html/HTMLElement.cpp:
(WebCore::HTMLElement::togglePopover):

Canonical link: https://commits.webkit.org/265589@main

LayoutTests/imported/w3c/web-platform-tests/html/semantics/popovers/togglePopover-expected.txt

@@ -1,4 +1,5 @@
 
 PASS togglePopover should toggle the popover and return true or false as specified.
 PASS togglePopover's return value should reflect what the end state is, not just the force parameter.
+PASS togglePopover should throw an exception when there is no popover attribute.
 

LayoutTests/imported/w3c/web-platform-tests/html/semantics/popovers/togglePopover.html

@@ -44,4 +44,34 @@
   // but every way to prevent that from hiding the popover also throws an
   // exception, so the return value is not testable.
 }, `togglePopover's return value should reflect what the end state is, not just the force parameter.`);
+
+
+test(() => {
+  const popover = document.createElement('div');
+  document.body.appendChild(popover);
+
+  assert_throws_dom('NotSupportedError', () => popover.togglePopover(),
+    'togglePopover() should throw an exception when the element has no popover attribute.');
+  assert_throws_dom('NotSupportedError', () => popover.togglePopover(true),
+    'togglePopover(true) should throw an exception when the element has no popover attribute.');
+  assert_throws_dom('NotSupportedError', () => popover.togglePopover(false),
+    'togglePopover(false) should throw an exception when the element has no popover attribute.');
+
+  popover.setAttribute('popover', 'auto');
+  popover.remove();
+
+  assert_throws_dom('InvalidStateError', () => popover.togglePopover(),
+    'togglePopover() should throw an exception when the element is disconnected.');
+  assert_throws_dom('InvalidStateError', () => popover.togglePopover(true),
+    'togglePopover(true) should throw an exception when the element is disconnected.');
+  assert_throws_dom('InvalidStateError', () => popover.togglePopover(false),
+    'togglePopover(false) should throw an exception when the element is disconnected.');
+
+  document.body.appendChild(popover);
+  // togglePopover(false) should not throw just because the popover is already hidden.
+  popover.togglePopover(false);
+  popover.showPopover();
+  // togglePopover(true) should not throw just because the popover is already showing.
+  popover.togglePopover(true);
+}, 'togglePopover should throw an exception when there is no popover attribute.');
 </script>

Source/WebCore/html/HTMLElement.cpp

@@ -1489,6 +1489,10 @@ ExceptionOr<bool> HTMLElement::togglePopover(std::optional<bool> force)
         auto returnValue = showPopover();
         if (returnValue.hasException())
             return returnValue.releaseException();
+    } else {
+        auto check = checkPopoverValidity(*this, popoverData() ? popoverData()->visibilityState() : PopoverVisibilityState::Showing);
+        if (check.hasException())
+            return check.releaseException();
     }
     return isPopoverShowing();
 }