Element.matches, Element.hasAttributes and DOMStringMap (Element.dataset)

src/browser/Page.zig

@@ -63,6 +63,9 @@ _attribute_lookup: std.AutoHashMapUnmanaged(usize, *Element.Attribute),
 // the return of elements.attributes.
 _attribute_named_node_map_lookup: std.AutoHashMapUnmanaged(usize, *Element.Attribute.NamedNodeMap),
 
+// element.dataset -> DOMStringMap
+_element_datasets: std.AutoHashMapUnmanaged(*Element, *Element.DOMStringMap),
+
 _script_manager: ScriptManager,
 
 _polyfill_loader: polyfill.Loader = .{},
@@ -152,6 +155,7 @@ fn reset(self: *Page, comptime initializing: bool) !void {
     self._load_state = .parsing;
     self._attribute_lookup = .empty;
     self._attribute_named_node_map_lookup = .empty;
+    self._element_datasets = .empty;
     self._event_manager = EventManager.init(self);
 
     self._script_manager = ScriptManager.init(self);

src/browser/ScriptManager.zig

@@ -707,7 +707,6 @@ const Script = struct {
             .cacheable = cacheable,
         });
 
-
         // Handle importmap special case here: the content is a JSON containing
         // imports.
         if (self.kind == .importmap) {

src/browser/js/Caller.zig

@@ -157,7 +157,7 @@ pub fn _getIndex(self: *Caller, comptime T: type, func: anytype, idx: u32, info:
     @field(args, "0") = try Context.typeTaggedAnyOpaque(*T, info.getThis());
     @field(args, "1") = idx;
     const ret = @call(.auto, func, args);
-    return self.handleIndexedReturn(T, F, ret, info, opts);
+    return self.handleIndexedReturn(T, F, true, ret, info, opts);
 }
 
 pub fn getNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.Name, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) u8 {
@@ -173,10 +173,49 @@ pub fn _getNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.N
     @field(args, "0") = try Context.typeTaggedAnyOpaque(*T, info.getThis());
     @field(args, "1") = try self.nameToString(name);
     const ret = @call(.auto, func, args);
-    return self.handleIndexedReturn(T, F, ret, info, opts);
+    return self.handleIndexedReturn(T, F, true, ret, info, opts);
 }
 
-fn handleIndexedReturn(self: *Caller, comptime T: type, comptime F: type, ret: anytype, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) !u8 {
+pub fn setNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.Name, js_value: v8.Value, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) u8 {
+    return self._setNamedIndex(T, func, name, js_value, info, opts) catch |err| {
+        self.handleError(T, @TypeOf(func), err, info, opts);
+        return v8.Intercepted.No;
+    };
+}
+
+pub fn _setNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.Name, js_value: v8.Value, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) !u8 {
+    const F = @TypeOf(func);
+    var args: ParameterTypes(F) = undefined;
+    @field(args, "0") = try Context.typeTaggedAnyOpaque(*T, info.getThis());
+    @field(args, "1") = try self.nameToString(name);
+    @field(args, "2") = try self.context.jsValueToZig(@TypeOf(@field(args, "2")), js_value);
+    if (@typeInfo(F).@"fn".params.len == 4) {
+        @field(args, "3") = self.context.page;
+    }
+    const ret = @call(.auto, func, args);
+    return self.handleIndexedReturn(T, F, false, ret, info, opts);
+}
+
+pub fn deleteNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.Name, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) u8 {
+    return self._deleteNamedIndex(T, func, name, info, opts) catch |err| {
+        self.handleError(T, @TypeOf(func), err, info, opts);
+        return v8.Intercepted.No;
+    };
+}
+
+pub fn _deleteNamedIndex(self: *Caller, comptime T: type, func: anytype, name: v8.Name, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) !u8 {
+    const F = @TypeOf(func);
+    var args: ParameterTypes(F) = undefined;
+    @field(args, "0") = try Context.typeTaggedAnyOpaque(*T, info.getThis());
+    @field(args, "1") = try self.nameToString(name);
+    if (@typeInfo(F).@"fn".params.len == 3) {
+        @field(args, "2") = self.context.page;
+    }
+    const ret = @call(.auto, func, args);
+    return self.handleIndexedReturn(T, F, false, ret, info, opts);
+}
+
+fn handleIndexedReturn(self: *Caller, comptime T: type, comptime F: type, comptime getter: bool, ret: anytype, info: v8.PropertyCallbackInfo, comptime opts: CallOpts) !u8 {
     // need to unwrap this error immediately for when opts.null_as_undefined == true
     // and we need to compare it to null;
     const non_error_ret = switch (@typeInfo(@TypeOf(ret))) {
@@ -197,7 +236,9 @@ fn handleIndexedReturn(self: *Caller, comptime T: type, comptime F: type, ret: a
         else => ret,
     };
 
-    info.getReturnValue().set(try self.context.zigValueToJs(non_error_ret, opts));
+    if (comptime getter) {
+        info.getReturnValue().set(try self.context.zigValueToJs(non_error_ret, opts));
+    }
     return v8.Intercepted.Yes;
 }
 

src/browser/js/Env.zig

@@ -253,13 +253,12 @@ pub fn attachClass(comptime JsApi: type, isolate: v8.Isolate, template: v8.Funct
                 };
                 template_proto.setIndexedProperty(configuration, null);
             },
-            bridge.NamedIndexed => {
+            bridge.NamedIndexed => template.getInstanceTemplate().setNamedProperty(.{
-                const configuration = v8.NamedPropertyHandlerConfiguration{
+                .getter = value.getter,
-                    .getter = value.getter,
+                .setter = value.setter,
-                    .flags = v8.PropertyHandlerFlags.OnlyInterceptStrings | v8.PropertyHandlerFlags.NonMasking,
+                .deleter = value.deleter,
-                };
+                .flags = v8.PropertyHandlerFlags.OnlyInterceptStrings | v8.PropertyHandlerFlags.NonMasking,
-                template_proto.setNamedProperty(configuration, null);
+            }, null),
-            },
             bridge.Iterator => {
                 // Same as a function, but with a specific name
                 const function_template = v8.FunctionTemplate.initCallback(isolate, value.func);
@@ -326,7 +325,6 @@ fn generateConstructor(comptime JsApi: type, isolate: v8.Isolate) v8.FunctionTem
 
 //     if (has_js_call_as_function) {
 
-
 //     if (@hasDecl(Struct, "htmldda") and Struct.htmldda) {
 //         if (!has_js_call_as_function) {
 //             @compileError(@typeName(Struct) ++ ": htmldda required jsCallAsFunction to be defined. This is a hard-coded requirement in V8, because mark_as_undetectable only exists for HTMLAllCollection which is also callable.");

src/browser/js/bridge.zig

@@ -45,8 +45,8 @@ pub fn Builder(comptime T: type) type {
             return Indexed.init(T, getter_func, opts);
         }
 
-        pub fn namedIndexed(comptime getter_func: anytype, comptime opts: NamedIndexed.Opts) NamedIndexed {
+        pub fn namedIndexed(comptime getter_func: anytype, setter_func: anytype, deleter_func: anytype, comptime opts: NamedIndexed.Opts) NamedIndexed {
-            return NamedIndexed.init(T, getter_func, opts);
+            return NamedIndexed.init(T, getter_func, setter_func, deleter_func, opts);
         }
 
         pub fn iterator(comptime func: anytype, comptime opts: Iterator.Opts) Iterator {
@@ -221,14 +221,16 @@ pub const Indexed = struct {
 
 pub const NamedIndexed = struct {
     getter: *const fn (c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8,
+    setter: ?*const fn (c_name: ?*const v8.C_Name, c_value: ?*const v8.C_Value, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 = null,
+    deleter: ?*const fn (c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 = null,
 
     const Opts = struct {
         as_typed_array: bool = false,
         null_as_undefined: bool = false,
     };
 
-    fn init(comptime T: type, comptime getter: anytype, comptime opts: Opts) NamedIndexed {
+    fn init(comptime T: type, comptime getter: anytype, setter: anytype, deleter: anytype, comptime opts: Opts) NamedIndexed {
-        return .{ .getter = struct {
+        const getter_fn = struct {
             fn wrap(c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
                 const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
                 var caller = Caller.init(info);
@@ -238,7 +240,39 @@ pub const NamedIndexed = struct {
                     .null_as_undefined = opts.null_as_undefined,
                 });
             }
-        }.wrap };
+        }.wrap;
+
+        const setter_fn = if (@typeInfo(@TypeOf(setter)) == .null) null else struct {
+            fn wrap(c_name: ?*const v8.C_Name, c_value: ?*const v8.C_Value, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
+                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
+                var caller = Caller.init(info);
+                defer caller.deinit();
+
+                return caller.setNamedIndex(T, setter, .{ .handle = c_name.? }, .{ .handle = c_value.? }, info, .{
+                    .as_typed_array = opts.as_typed_array,
+                    .null_as_undefined = opts.null_as_undefined,
+                });
+            }
+        }.wrap;
+
+        const deleter_fn = if (@typeInfo(@TypeOf(deleter)) == .null) null else struct {
+            fn wrap(c_name: ?*const v8.C_Name, raw_info: ?*const v8.C_PropertyCallbackInfo) callconv(.c) u8 {
+                const info = v8.PropertyCallbackInfo.initFromV8(raw_info);
+                var caller = Caller.init(info);
+                defer caller.deinit();
+
+                return caller.deleteNamedIndex(T, deleter, .{ .handle = c_name.? }, info, .{
+                    .as_typed_array = opts.as_typed_array,
+                    .null_as_undefined = opts.null_as_undefined,
+                });
+            }
+        }.wrap;
+
+        return .{
+            .getter = getter_fn,
+            .setter = setter_fn,
+            .deleter = deleter_fn,
+        };
     }
 };
 
@@ -269,7 +303,6 @@ pub const Iterator = struct {
     }
 };
 
-
 pub const Callable = struct {
     func: *const fn (?*const v8.C_FunctionCallbackInfo) callconv(.c) void,
 
@@ -278,7 +311,7 @@ pub const Callable = struct {
     };
 
     fn init(comptime T: type, comptime func: anytype, comptime opts: Opts) Callable {
-        return .{.func = struct {
+        return .{ .func = struct {
             fn wrap(raw_info: ?*const v8.C_FunctionCallbackInfo) callconv(.c) void {
                 const info = v8.FunctionCallbackInfo.initFromV8(raw_info);
                 var caller = Caller.init(info);
@@ -286,8 +319,8 @@ pub const Callable = struct {
                 caller.method(T, func, info, .{
                     .null_as_undefined = opts.null_as_undefined,
                 });
-            }}.wrap
+            }
-        };
+        }.wrap };
     }
 };
 
@@ -457,6 +490,7 @@ pub const JsApis = flattenTypes(&.{
     @import("../webapi/DOMNodeIterator.zig"),
     @import("../webapi/NodeFilter.zig"),
     @import("../webapi/Element.zig"),
+    @import("../webapi/element/DOMStringMap.zig"),
     @import("../webapi/element/Attribute.zig"),
     @import("../webapi/element/Html.zig"),
     @import("../webapi/element/html/IFrame.zig"),

src/browser/tests/element/attributes.html

@@ -83,3 +83,22 @@
 
   assertAttributes([{name: 'id', value: 'attr1'}, {name: 'class', value: 'sHow'}]);
 </script>
+
+<script id=hasAttribute>
+{
+  const el1 = $('#attr1');
+
+  testing.expectEqual(true, el1.hasAttribute('id'));
+  testing.expectEqual(true, el1.hasAttribute('ID'));
+  testing.expectEqual(true, el1.hasAttribute('class'));
+  testing.expectEqual(true, el1.hasAttribute('CLASS'));
+  testing.expectEqual(false, el1.hasAttribute('other'));
+  testing.expectEqual(false, el1.hasAttribute('nope'));
+
+  el1.setAttribute('data-test', 'value');
+  testing.expectEqual(true, el1.hasAttribute('data-test'));
+
+  el1.removeAttribute('data-test');
+  testing.expectEqual(false, el1.hasAttribute('data-test'));
+}
+</script>

src/browser/tests/element/dataset.html

@@ -0,0 +1,150 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+
+<div id="test" data-foo="bar" data-hello-world="test"></div>
+<div id="test-write"></div>
+<div id="test-bracket"></div>
+
+<script id=basic>
+{
+  const el = document.getElementById('test');
+  testing.expectEqual('object', typeof el.dataset);
+}
+</script>
+
+<script id=readExistingAttributes>
+{
+  const el = document.getElementById('test');
+  testing.expectEqual('bar', el.dataset.foo);
+  testing.expectEqual('test', el.dataset.helloWorld);
+}
+</script>
+
+<script id=camelCaseConversion>
+{
+  const el = document.getElementById('test');
+
+  // Reading kebab-case as camelCase
+  testing.expectEqual('test', el.dataset.helloWorld);
+}
+</script>
+
+<script id=writeNewAttribute>
+{
+  const el = document.getElementById('test-write');
+  el.dataset.newAttr = 'value';
+
+  testing.expectEqual('value', el.dataset.newAttr);
+  testing.expectEqual('value', el.getAttribute('data-new-attr'));
+}
+</script>
+
+<script id=writeExistingAttribute>
+{
+  const el = document.getElementById('test-write');
+  el.setAttribute('data-foo', 'original');
+  el.dataset.foo = 'updated';
+
+  testing.expectEqual('updated', el.dataset.foo);
+  testing.expectEqual('updated', el.getAttribute('data-foo'));
+}
+</script>
+
+<script id=writeCamelCaseConversion>
+{
+  const el = document.getElementById('test-write');
+
+  // Writing camelCase creates kebab-case attribute
+  el.dataset.fooBarBaz = 'qux';
+  testing.expectEqual('qux', el.getAttribute('data-foo-bar-baz'));
+}
+</script>
+
+<script id=undefinedForNonExistent>
+{
+  const el = document.getElementById('test');
+  testing.expectEqual(undefined, el.dataset.nonExistent);
+}
+</script>
+
+<script id=bracketNotation>
+{
+  const el = document.getElementById('test-bracket');
+  el.setAttribute('data-foo', 'bar');
+  el.setAttribute('data-hello-world', 'test');
+
+  // Bracket notation should work the same as dot notation
+  testing.expectEqual('bar', el.dataset['foo']);
+  testing.expectEqual('test', el.dataset['helloWorld']);
+
+  // Non-existent should return undefined
+  testing.expectEqual(undefined, el.dataset['nonExistent']);
+}
+</script>
+
+<script id=edgeCases>
+{
+  const el = document.createElement('div');
+  el.setAttribute('data-x', 'single-letter');
+  el.setAttribute('data-foo-bar-baz', 'multiple-dashes');
+
+  // Single letter key
+  testing.expectEqual('single-letter', el.dataset['x']);
+  testing.expectEqual('single-letter', el.dataset.x);
+
+  // Multiple dashes
+  testing.expectEqual('multiple-dashes', el.dataset['fooBarBaz']);
+  testing.expectEqual('multiple-dashes', el.dataset.fooBarBaz);
+
+  // Empty string key (data- attribute) - should be accessible as empty string
+  el.setAttribute('data-', 'empty');
+  testing.expectEqual('empty', el.dataset['']);
+}
+</script>
+
+<script id=identityCheck>
+{
+  const el = document.getElementById('test');
+  const ds1 = el.dataset;
+  const ds2 = el.dataset;
+
+  // Should return the same object instance
+  testing.expectEqual(true, ds1 === ds2);
+}
+</script>
+
+<script id=deleteProperty>
+{
+  const el = document.createElement('div');
+  el.setAttribute('data-foo', 'bar');
+  el.setAttribute('data-hello-world', 'test');
+
+  testing.expectEqual('bar', el.dataset.foo);
+  testing.expectEqual('test', el.dataset.helloWorld);
+
+  // Delete using dot notation
+  delete el.dataset.foo;
+  testing.expectEqual(undefined, el.dataset.foo);
+  testing.expectEqual(null, el.getAttribute('data-foo'));
+
+  // Delete using bracket notation
+  delete el.dataset['helloWorld'];
+  testing.expectEqual(undefined, el.dataset.helloWorld);
+  testing.expectEqual(null, el.getAttribute('data-hello-world'));
+}
+</script>
+
+<script id=independentInstances>
+{
+  const el1 = document.getElementById('test');
+  const el2 = document.createElement('div');
+
+  el1.dataset.test1 = 'value1';
+  el2.dataset.test2 = 'value2';
+
+  testing.expectEqual('value1', el1.dataset.test1);
+  testing.expectEqual(undefined, el1.dataset.test2);
+  testing.expectEqual(undefined, el2.dataset.test1);
+  testing.expectEqual('value2', el2.dataset.test2);
+}
+</script>

src/browser/tests/element/matches.html

@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<script src="../testing.js"></script>
+
+<div id="test-container" class="container main">
+  <p class="text highlight">Paragraph 1</p>
+  <div class="nested">
+    <p class="text">Paragraph 2</p>
+    <span id="special" class="wrapper">
+      <p class="deep">Paragraph 3</p>
+    </span>
+  </div>
+</div>
+
+<script id=basicMatches>
+{
+  const container = $('#test-container');
+
+  testing.expectEqual(true, container.matches('#test-container'));
+  testing.expectEqual(false, container.matches('#other'));
+
+  testing.expectEqual(true, container.matches('.container'));
+  testing.expectEqual(true, container.matches('.main'));
+  testing.expectEqual(false, container.matches('.nested'));
+
+  testing.expectEqual(true, container.matches('div'));
+  testing.expectEqual(false, container.matches('p'));
+
+  testing.expectEqual(true, container.matches('div.container'));
+  testing.expectEqual(true, container.matches('div#test-container'));
+  testing.expectEqual(true, container.matches('.container.main'));
+  testing.expectEqual(false, container.matches('div.nested'));
+
+  testing.expectEqual(true, container.matches('*'));
+}
+</script>
+
+<script id=childMatches>
+{
+  const paragraph = $('#test-container > p');
+
+  testing.expectEqual(true, paragraph.matches('p'));
+  testing.expectEqual(true, paragraph.matches('.text'));
+  testing.expectEqual(true, paragraph.matches('.highlight'));
+  testing.expectEqual(true, paragraph.matches('p.text.highlight'));
+
+  testing.expectEqual(false, paragraph.matches('#test-container'));
+  testing.expectEqual(false, paragraph.matches('div'));
+}
+</script>
+
+<script id=specialSpan>
+{
+  const span = $('#special');
+
+  testing.expectEqual(true, span.matches('#special'));
+  testing.expectEqual(true, span.matches('span'));
+  testing.expectEqual(true, span.matches('.wrapper'));
+  testing.expectEqual(true, span.matches('span.wrapper'));
+  testing.expectEqual(true, span.matches('span#special.wrapper'));
+  testing.expectEqual(false, span.matches('#other'));
+  testing.expectEqual(false, span.matches('div'));
+}
+</script>
+
+<script id=errorHandling>
+{
+  const container = $('#test-container');
+
+  testing.expectError("Syntax Error", () => container.matches(''));
+  testing.withError((err) => {
+    testing.expectEqual(12, err.code);
+    testing.expectEqual("SyntaxError", err.name);
+    testing.expectEqual("Syntax Error", err.message);
+  }, () => container.matches(''));
+}
+</script>

src/browser/webapi/Document.zig

@@ -195,11 +195,11 @@ pub const JsApi = struct {
     pub const querySelectorAll = bridge.function(Document.querySelectorAll, .{ .dom_exception = true });
     pub const getElementsByTagName = bridge.function(Document.getElementsByTagName, .{});
     pub const getElementsByClassName = bridge.function(Document.getElementsByClassName, .{});
-    pub const defaultView = bridge.accessor(struct{
+    pub const defaultView = bridge.accessor(struct {
         fn defaultView(_: *const Document, page: *Page) *@import("Window.zig") {
             return page.window;
         }
-    }.defaultView, null, .{.cache = "defaultView"});
+    }.defaultView, null, .{ .cache = "defaultView" });
 };
 
 const testing = @import("../../testing.zig");

src/browser/webapi/Element.zig

@@ -12,6 +12,7 @@ const collections = @import("collections.zig");
 const Selector = @import("selector/Selector.zig");
 pub const Attribute = @import("element/Attribute.zig");
 const CSSStyleProperties = @import("css/CSSStyleProperties.zig");
+pub const DOMStringMap = @import("element/DOMStringMap.zig");
 
 pub const Svg = @import("element/Svg.zig");
 pub const Html = @import("element/Html.zig");
@@ -247,6 +248,12 @@ pub fn getAttribute(self: *const Element, name: []const u8, page: *Page) !?[]con
     return attributes.get(name, page);
 }
 
+pub fn hasAttribute(self: *const Element, name: []const u8, page: *Page) !bool {
+    const attributes = self._attributes orelse return false;
+    const value = try attributes.get(name, page);
+    return value != null;
+}
+
 pub fn getAttributeNode(self: *Element, name: []const u8, page: *Page) !?*Attribute {
     const attributes = self._attributes orelse return null;
     return attributes.getAttribute(name, self, page);
@@ -342,6 +349,16 @@ pub fn getClassList(self: *Element, page: *Page) !*collections.DOMTokenList {
     };
 }
 
+pub fn getDataset(self: *Element, page: *Page) !*DOMStringMap {
+    const gop = try page._element_datasets.getOrPut(page.arena, self);
+    if (!gop.found_existing) {
+        gop.value_ptr.* = try page._factory.create(DOMStringMap{
+            ._element = self,
+        });
+    }
+    return gop.value_ptr.*;
+}
+
 pub fn replaceChildren(self: *Element, nodes: []const Node.NodeOrText, page: *Page) !void {
     page.domChanged();
     var parent = self.asNode();
@@ -438,6 +455,10 @@ pub fn getChildElementCount(self: *Element) usize {
     return count;
 }
 
+pub fn matches(self: *Element, selector: []const u8, page: *Page) !bool {
+    return Selector.matches(self, selector, page);
+}
+
 pub fn querySelector(self: *Element, selector: []const u8, page: *Page) !?*Element {
     return Selector.querySelector(self.asNode(), selector, page);
 }
@@ -658,8 +679,10 @@ pub const JsApi = struct {
     pub const id = bridge.accessor(Element.getId, Element.setId, .{});
     pub const className = bridge.accessor(Element.getClassName, Element.setClassName, .{});
     pub const classList = bridge.accessor(Element.getClassList, null, .{});
+    pub const dataset = bridge.accessor(Element.getDataset, null, .{});
     pub const style = bridge.accessor(Element.getStyle, null, .{});
     pub const attributes = bridge.accessor(Element.getAttributeNamedNodeMap, null, .{});
+    pub const hasAttribute = bridge.function(Element.hasAttribute, .{});
     pub const getAttribute = bridge.function(Element.getAttribute, .{});
     pub const getAttributeNode = bridge.function(Element.getAttributeNode, .{});
     pub const setAttribute = bridge.function(Element.setAttribute, .{});
@@ -676,6 +699,7 @@ pub const JsApi = struct {
     pub const nextElementSibling = bridge.accessor(Element.nextElementSibling, null, .{});
     pub const previousElementSibling = bridge.accessor(Element.previousElementSibling, null, .{});
     pub const childElementCount = bridge.accessor(Element.getChildElementCount, null, .{});
+    pub const matches = bridge.function(Element.matches, .{ .dom_exception = true });
     pub const querySelector = bridge.function(Element.querySelector, .{ .dom_exception = true });
     pub const querySelectorAll = bridge.function(Element.querySelectorAll, .{ .dom_exception = true });
     pub const getElementsByTagName = bridge.function(Element.getElementsByTagName, .{});

src/browser/webapi/KeyValueList.zig

@@ -45,7 +45,7 @@ pub fn get(self: *const KeyValueList, name: []const u8) ?[]const u8 {
     return null;
 }
 
-pub fn getAll(self: *const KeyValueList, name: []const u8, page: *Page) ![]const []const u8  {
+pub fn getAll(self: *const KeyValueList, name: []const u8, page: *Page) ![]const []const u8 {
     const arena = page.call_arena;
     var arr: std.ArrayList([]const u8) = .empty;
     for (self._entries.items) |*entry| {

src/browser/webapi/Node.zig

@@ -614,9 +614,7 @@ pub const JsApi = struct {
 
     pub const textContent = bridge.accessor(_textContext, Node.setTextContent, .{});
     fn _textContext(self: *Node, page: *const Page) !?[]const u8 {
-        // can't call node.getTextContent directly, because
+        // cdata and attributes can return value directly, avoiding the copy
-        // 1 - document should return null, not empty
-        // 2 - cdata and attributes can return value directly, avoiding the copy
         switch (self._type) {
             .element => |el| {
                 var buf = std.Io.Writer.Allocating.init(page.call_arena);

src/browser/webapi/Window.zig

@@ -149,7 +149,7 @@ pub fn cancelAnimationFrame(self: *Window, id: u32) void {
 
 pub fn reportError(self: *Window, err: js.Object, page: *Page) !void {
     const error_event = try ErrorEvent.init("error", .{
-        .@"error" =  err,
+        .@"error" = err,
         .message = err.toString() catch "Unknown error",
         .bubbles = false,
         .cancelable = true,

src/browser/webapi/collections/HTMLAllCollection.zig

@@ -152,7 +152,7 @@ pub const JsApi = struct {
 
     pub const length = bridge.accessor(HTMLAllCollection.length, null, .{});
     pub const @"[int]" = bridge.indexed(HTMLAllCollection.getAtIndex, .{ .null_as_undefined = true });
-    pub const @"[str]" = bridge.namedIndexed(HTMLAllCollection.getByName, .{ .null_as_undefined = true });
+    pub const @"[str]" = bridge.namedIndexed(HTMLAllCollection.getByName, null, null, .{ .null_as_undefined = true });
 
     pub const item = bridge.function(_item, .{});
     fn _item(self: *HTMLAllCollection, index: i32, page: *Page) ?*Element {

src/browser/webapi/collections/HTMLCollection.zig

@@ -83,7 +83,7 @@ pub const JsApi = struct {
 
     pub const length = bridge.accessor(HTMLCollection.length, null, .{});
     pub const @"[int]" = bridge.indexed(HTMLCollection.getAtIndex, .{ .null_as_undefined = true });
-    pub const @"[str]" = bridge.namedIndexed(HTMLCollection.getByName, .{ .null_as_undefined = true });
+    pub const @"[str]" = bridge.namedIndexed(HTMLCollection.getByName, null, null, .{ .null_as_undefined = true });
 
     pub const item = bridge.function(_item, .{});
     fn _item(self: *HTMLCollection, index: i32, page: *Page) ?*Element {

src/browser/webapi/css/CSSStyleProperties.zig

@@ -120,7 +120,7 @@ pub const JsApi = struct {
         pub var class_id: bridge.ClassId = undefined;
     };
 
-    pub const @"[]" = bridge.namedIndexed(_getPropertyIndexed, .{});
+    pub const @"[]" = bridge.namedIndexed(_getPropertyIndexed, null, null, .{});
 
     const method_names = std.StaticStringMap(void).initComptime(.{
         .{ "getPropertyValue", {} },

src/browser/webapi/css/MediaQueryList.zig

@@ -31,7 +31,7 @@ pub const JsApi = struct {
     pub const Meta = struct {
         pub const name = "MediaQueryList";
         pub const prototype_chain = bridge.prototypeChain();
-        pub var class_id: bridge.ClassId  = undefined;
+        pub var class_id: bridge.ClassId = undefined;
     };
 
     pub const media = bridge.accessor(MediaQueryList.getMedia, null, .{});

src/browser/webapi/element/Attribute.zig

@@ -386,7 +386,7 @@ pub const NamedNodeMap = struct {
 
         pub const length = bridge.accessor(NamedNodeMap.length, null, .{});
         pub const @"[int]" = bridge.indexed(NamedNodeMap.getAtIndex, .{ .null_as_undefined = true });
-        pub const @"[str]" = bridge.namedIndexed(NamedNodeMap.getByName, .{ .null_as_undefined = true });
+        pub const @"[str]" = bridge.namedIndexed(NamedNodeMap.getByName, null, null, .{ .null_as_undefined = true });
         pub const getNamedItem = bridge.function(NamedNodeMap.getByName, .{});
         pub const item = bridge.function(_item, .{});
         fn _item(self: *const NamedNodeMap, index: i32, page: *Page) !?*Attribute {

src/browser/webapi/element/DOMStringMap.zig

@@ -0,0 +1,87 @@
+const std = @import("std");
+const js = @import("../../js/js.zig");
+
+const Element = @import("../Element.zig");
+const Page = @import("../../Page.zig");
+
+const Allocator = std.mem.Allocator;
+
+const DOMStringMap = @This();
+
+_element: *Element,
+
+fn _getProperty(self: *DOMStringMap, name: []const u8, page: *Page) !?[]const u8 {
+    const attr_name = try camelToKebab(page.call_arena, name);
+    return try self._element.getAttribute(attr_name, page);
+}
+
+fn _setProperty(self: *DOMStringMap, name: []const u8, value: []const u8, page: *Page) !void {
+    const attr_name = try camelToKebab(page.call_arena, name);
+    return self._element.setAttributeSafe(attr_name, value, page);
+}
+
+fn _deleteProperty(self: *DOMStringMap, name: []const u8, page: *Page) !void {
+    const attr_name = try camelToKebab(page.call_arena, name);
+    try self._element.removeAttribute(attr_name, page);
+}
+
+// fooBar -> foo-bar
+fn camelToKebab(arena: Allocator, camel: []const u8) ![]const u8 {
+    var result: std.ArrayList(u8) = .empty;
+    try result.ensureTotalCapacity(arena, 5 + camel.len * 2);
+    result.appendSliceAssumeCapacity("data-");
+
+    for (camel, 0..) |c, i| {
+        if (std.ascii.isUpper(c)) {
+            if (i > 0) {
+                result.appendAssumeCapacity('-');
+            }
+            result.appendAssumeCapacity(std.ascii.toLower(c));
+        } else {
+            result.appendAssumeCapacity(c);
+        }
+    }
+
+    return result.items;
+}
+
+// data-foo-bar -> fooBar
+fn kebabToCamel(arena: Allocator, kebab: []const u8) !?[]const u8 {
+    if (!std.mem.startsWith(u8, kebab, "data-")) {
+        return null;
+    }
+
+    const data_part = kebab[5..]; // Skip "data-"
+    if (data_part.len == 0) {
+        return null;
+    }
+
+    var result: std.ArrayList(u8) = .empty;
+    try result.ensureTotalCapacity(arena, data_part.len);
+
+    var capitalize_next = false;
+    for (data_part) |c| {
+        if (c == '-') {
+            capitalize_next = true;
+        } else if (capitalize_next) {
+            result.appendAssumeCapacity(std.ascii.toUpper(c));
+            capitalize_next = false;
+        } else {
+            result.appendAssumeCapacity(c);
+        }
+    }
+
+    return result.items;
+}
+
+pub const JsApi = struct {
+    pub const bridge = js.Bridge(DOMStringMap);
+
+    pub const Meta = struct {
+        pub const name = "DOMStringMap";
+        pub const prototype_chain = bridge.prototypeChain();
+        pub var class_id: bridge.ClassId = undefined;
+    };
+
+    pub const @"[]" = bridge.namedIndexed(_getProperty, _setProperty, _deleteProperty, .{.null_as_undefined = true});
+};

src/browser/webapi/element/html/Body.zig

@@ -33,7 +33,7 @@ pub const Build = struct {
         const el = node.as(Element);
         const on_load = el.getAttributeSafe("onload") orelse return;
         page.window._on_load = page.js.stringToFunction(on_load) catch |err| blk: {
-            log.err(.js, "body.onload", .{.err = err, .str = on_load});
+            log.err(.js, "body.onload", .{ .err = err, .str = on_load });
             break :blk null;
         };
     }

src/browser/webapi/element/html/Script.zig

@@ -80,14 +80,14 @@ pub const Build = struct {
 
         if (element.getAttributeSafe("onload")) |on_load| {
             self._on_load = page.js.stringToFunction(on_load) catch |err| blk: {
-                log.err(.js, "script.onload", .{.err = err, .str = on_load});
+                log.err(.js, "script.onload", .{ .err = err, .str = on_load });
                 break :blk null;
             };
         }
 
         if (element.getAttributeSafe("onerror")) |on_error| {
             self._on_error = page.js.stringToFunction(on_error) catch |err| blk: {
-                log.err(.js, "script.onerror", .{.err = err, .str = on_error});
+                log.err(.js, "script.onerror", .{ .err = err, .str = on_error });
                 break :blk null;
             };
         }

src/browser/webapi/selector/Parser.zig

@@ -77,7 +77,6 @@ pub fn parse(arena: Allocator, input: []const u8, page: *Page) ParseError!Select
     var segments: std.ArrayList(Segment) = .empty;
     var current_compound: std.ArrayList(Part) = .empty;
 
-
     // Parse the first compound (no combinator before it)
     while (parser.skipSpaces()) {
         if (parser.peek() == 0) break;