Fix HTMLCollection named property issues

1 - Named properties should not be enumerable
2 - Empty key should always result in a null/undefined (depending on the API)
    even if there's an element with an empty id/name

To address the first issue, we now require PropertyAttributes to be specified
when setting an object's value.

Author: karlseguin

src/browser/dom/html_collection.zig

@@ -406,10 +406,16 @@ 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);
+            try js_this.setIndex(@intCast(i), e, .{});
 
             if (try item_name(e)) |name| {
-                try js_this.set(name, e);
+                // 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 });
+                }
             }
         }
     }

src/browser/dom/nodelist.zig

@@ -173,7 +173,7 @@ pub const NodeList = struct {
         const len = self.get_length();
         for (0..len) |i| {
             const node = try self._item(@intCast(i)) orelse unreachable;
-            try js_this.setIndex(i, node);
+            try js_this.setIndex(@intCast(i), node, .{});
         }
     }
 };

src/runtime/js.zig

@@ -894,20 +894,28 @@ pub fn Env(comptime State: type, comptime WebApis: type) type {
             // for this declaration is _a lot_ easier.
             const _JSOBJECT_ID_KLUDGE = true;
 
-            pub fn setIndex(self: JsObject, index: usize, value: anytype) !void {
+            const SetOpts = packed struct(u32) {
+                READ_ONLY: bool = false,
+                DONT_ENUM: bool = false,
+                DONT_DELETE: bool = false,
+                _: u29 = 0,
+            };
+            pub fn setIndex(self: JsObject, index: u32, value: anytype, opts: SetOpts) !void {
                 const key = switch (index) {
                     inline 0...1000 => |i| std.fmt.comptimePrint("{d}", .{i}),
                     else => try std.fmt.allocPrint(self.scope.scope_arena, "{d}", .{index}),
                 };
-                return self.set(key, value);
+                return self.set(key, value, opts);
             }
 
-            pub fn set(self: JsObject, key: []const u8, value: anytype) !void {
+            pub fn set(self: JsObject, key: []const u8, value: anytype, opts: SetOpts) !void {
                 const scope = self.scope;
 
                 const js_key = v8.String.initUtf8(scope.isolate, key);
                 const js_value = try scope.zigValueToJs(value);
-                if (!self.js_obj.setValue(scope.context, js_key, js_value)) {
+
+                const res = self.js_obj.defineOwnProperty(scope.context, js_key.toName(), js_value, @bitCast(opts)) orelse false;
+                if (!res) {
                     return error.FailedToSet;
                 }
             }
@@ -957,12 +965,12 @@ pub fn Env(comptime State: type, comptime WebApis: type) type {
 
             const _JSTHIS_ID_KLUDGE = true;
 
-            pub fn setIndex(self: JsThis, index: usize, value: anytype) !void {
-                return self.obj.setIndex(index, value);
+            pub fn setIndex(self: JsThis, index: u32, value: anytype, opts: JsObject.SetOpts) !void {
+                return self.obj.setIndex(index, value, opts);
             }
 
-            pub fn set(self: JsThis, key: []const u8, value: anytype) !void {
-                return self.obj.set(key, value);
+            pub fn set(self: JsThis, key: []const u8, value: anytype, opts: JsObject.SetOpts) !void {
+                return self.obj.set(key, value, opts);
             }
         };