From 095413c6c5c95705451cb157e88a2f101099037b Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Fri, 21 Nov 2025 14:35:52 +0800
Subject: [PATCH] Element.toggleAttribute and InteresectionObserver init param
 overload

---
 src/browser/tests/element/attributes.html   | 33 +++++++++++++++++++++
 src/browser/webapi/Element.zig              | 17 +++++++++++
 src/browser/webapi/IntersectionObserver.zig | 18 +++++++++--
 3 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/src/browser/tests/element/attributes.html b/src/browser/tests/element/attributes.html
index d4d416f6..c1ce0767 100644
--- a/src/browser/tests/element/attributes.html
+++ b/src/browser/tests/element/attributes.html
@@ -102,3 +102,36 @@
   testing.expectEqual(false, el1.hasAttribute('data-test'));
 }
 </script>
+
+<script id=toggleAttribute>
+{
+  const el1 = $('#attr1');
+
+  // Toggle non-existent attribute (should add it and return true)
+  testing.expectEqual(false, el1.hasAttribute('toggle-test'));
+  testing.expectEqual(true, el1.toggleAttribute('toggle-test'));
+  testing.expectEqual(true, el1.hasAttribute('toggle-test'));
+  testing.expectEqual('', el1.getAttribute('toggle-test'));
+
+  // Toggle existing attribute (should remove it and return false)
+  testing.expectEqual(false, el1.toggleAttribute('toggle-test'));
+  testing.expectEqual(false, el1.hasAttribute('toggle-test'));
+
+  // Toggle with force=true when attribute doesn't exist (should add and return true)
+  testing.expectEqual(false, el1.hasAttribute('toggle-test'));
+  testing.expectEqual(true, el1.toggleAttribute('toggle-test', true));
+  testing.expectEqual(true, el1.hasAttribute('toggle-test'));
+
+  // Toggle with force=true when attribute exists (should keep and return true)
+  testing.expectEqual(true, el1.toggleAttribute('toggle-test', true));
+  testing.expectEqual(true, el1.hasAttribute('toggle-test'));
+
+  // Toggle with force=false when attribute exists (should remove and return false)
+  testing.expectEqual(false, el1.toggleAttribute('toggle-test', false));
+  testing.expectEqual(false, el1.hasAttribute('toggle-test'));
+
+  // Toggle with force=false when attribute doesn't exist (should keep removed and return false)
+  testing.expectEqual(false, el1.toggleAttribute('toggle-test', false));
+  testing.expectEqual(false, el1.hasAttribute('toggle-test'));
+}
+</script>
diff --git a/src/browser/webapi/Element.zig b/src/browser/webapi/Element.zig
index c4e3bf1d..023da510 100644
--- a/src/browser/webapi/Element.zig
+++ b/src/browser/webapi/Element.zig
@@ -354,6 +354,22 @@ pub fn removeAttribute(self: *Element, name: []const u8, page: *Page) !void {
     return attributes.delete(name, self, page);
 }
 
+pub fn toggleAttribute(self: *Element, name: []const u8, force: ?bool, page: *Page) !bool {
+    const has = try self.hasAttribute(name, page);
+
+    const should_add = force orelse !has;
+
+    if (should_add and !has) {
+        try self.setAttribute(name, "", page);
+        return true;
+    } else if (!should_add and has) {
+        try self.removeAttribute(name, page);
+        return false;
+    }
+
+    return should_add;
+}
+
 pub fn removeAttributeNode(self: *Element, attr: *Attribute, page: *Page) !*Attribute {
     if (attr._element == null or attr._element.? != self) {
         return error.NotFound;
@@ -909,6 +925,7 @@ pub const JsApi = struct {
     pub const setAttribute = bridge.function(Element.setAttribute, .{});
     pub const setAttributeNode = bridge.function(Element.setAttributeNode, .{});
     pub const removeAttribute = bridge.function(Element.removeAttribute, .{});
+    pub const toggleAttribute = bridge.function(Element.toggleAttribute, .{});
     pub const getAttributeNames = bridge.function(Element.getAttributeNames, .{});
     pub const removeAttributeNode = bridge.function(Element.removeAttributeNode, .{ .dom_exception = true });
     pub const shadowRoot = bridge.accessor(Element.getShadowRoot, null, .{});
diff --git a/src/browser/webapi/IntersectionObserver.zig b/src/browser/webapi/IntersectionObserver.zig
index 7198dfa7..d9722be7 100644
--- a/src/browser/webapi/IntersectionObserver.zig
+++ b/src/browser/webapi/IntersectionObserver.zig
@@ -53,18 +53,32 @@ var zero_rect: DOMRect = .{
 pub const ObserverInit = struct {
     root: ?*Element = null,
     rootMargin: ?[]const u8 = null,
-    threshold: []const f64 = &.{0.0},
+    threshold: Threshold = .{.scalar = 0.0},
+
+    const Threshold = union(enum) {
+        scalar: f64,
+        array: []const f64,
+    };
 };
 
 pub fn init(callback: js.Function, options: ?ObserverInit, page: *Page) !*IntersectionObserver {
     const opts = options orelse ObserverInit{};
     const root_margin = if (opts.rootMargin) |rm| try page.arena.dupe(u8, rm) else "0px";
 
+    const threshold = switch (opts.threshold) {
+        .scalar => |s| blk: {
+            const arr = try page.arena.alloc(f64, 1);
+            arr[0] = s;
+            break :blk arr;
+        },
+        .array => |arr| try page.arena.dupe(f64, arr),
+    };
+
     return page._factory.create(IntersectionObserver{
         ._callback = callback,
         ._root = opts.root,
         ._root_margin = root_margin,
-        ._threshold = try page.arena.dupe(f64, opts.threshold),
+        ._threshold = threshold
     });
 }