css: check if node is an html element

src/css/libdom.zig

@@ -20,6 +20,11 @@ pub const Node = struct {
         return null;
     }
 
+    pub fn isElement(n: Node) bool {
+        const t = parser.nodeType(n.node) catch return false;
+        return t == .element;
+    }
+
     pub fn tag(n: Node) ![]const u8 {
         return try parser.nodeName(n.node);
     }

src/css/match_test.zig

@@ -16,6 +16,10 @@ pub const Node = struct {
         return n.sibling;
     }
 
+    pub fn isElement(_: *const Node) bool {
+        return true;
+    }
+
     pub fn tag(n: *const Node) ![]const u8 {
         return n.name;
     }

src/css/selector.zig

@@ -167,7 +167,7 @@ pub const Selector = union(enum) {
 
     pub fn match(s: Selector, n: anytype) !bool {
         return switch (s) {
-            .tag => |v| std.ascii.eqlIgnoreCase(v, try n.tag()),
+            .tag => |v| n.isElement() and std.ascii.eqlIgnoreCase(v, try n.tag()),
             else => false,
         };
     }