Fix set_innerHTML, fix HTMLCollection fixed (postAttached) return type

src/browser/dom/element.zig

@@ -128,10 +128,10 @@ pub const Element = struct {
 
         // append children to the node
         const ln = try parser.nodeListLength(children);
-        var i: u32 = 0;
-        while (i < ln) {
-            defer i += 1;
-            const child = try parser.nodeListItem(children, i) orelse continue;
+        for (0..ln) |_| {
+            // always index 0, because ndoeAppendChild moves the node out of
+            // the nodeList and into the new tree
+            const child = try parser.nodeListItem(children, 0) orelse continue;
             _ = try parser.nodeAppendChild(node, child);
         }
     }
@@ -653,4 +653,10 @@ test "Browser.DOM.Element" {
         .{ "a1.after('over 9000', a1_a);", "undefined" },
         .{ "after_container.innerHTML", "<div></div>over 9000<p></p>" },
     }, .{});
+
+    try runner.testCases(&.{
+        .{ "var div1 = document.createElement('div');", null },
+        .{ "div1.innerHTML = \"  <link/><table></table><a href='/a'>a</a><input type='checkbox'/>\"", null },
+        .{ "div1.getElementsByTagName('a').length", "1" },
+    }, .{});
 }

src/browser/dom/html_collection.zig

@@ -432,15 +432,16 @@ pub const HTMLCollection = struct {
         for (0..len) |i| {
             const node = try self.item(@intCast(i)) orelse unreachable;
             const e = @as(*parser.Element, @ptrCast(node));
-            try js_this.setIndex(@intCast(i), e, .{});
+            const as_interface = try Element.toInterface(e);
+            try js_this.setIndex(@intCast(i), as_interface, .{});
 
             if (try item_name(e)) |name| {
                 // Even though an entry might have an empty id, the spec says
                 // that namedItem("") should always return null
                 if (name.len > 0) {
                     // Named fields should not be enumerable (it is defined with
                     // the LegacyUnenumerableNamedProperties flag.)
-                    try js_this.set(name, e, .{ .DONT_ENUM = true });
+                    try js_this.set(name, as_interface, .{ .DONT_ENUM = true });
                 }
             }
         }