diff --git a/src/browser/js/Value.zig b/src/browser/js/Value.zig
index af5dd031..1491bcdd 100644
--- a/src/browser/js/Value.zig
+++ b/src/browser/js/Value.zig
@@ -245,15 +245,37 @@ pub fn toJson(self: Value, allocator: Allocator) ![]u8 {
return js.String.toSliceWithAlloc(.{ .local = local, .handle = str_handle }, allocator);
}
-// Currently does not support host objects (Blob, File, etc.) or transferables
-// which require delegate callbacks to be implemented.
+// Throws a DataCloneError for host objects (Blob, File, etc.) that cannot be serialized.
+// Does not support transferables which require additional delegate callbacks.
pub fn structuredClone(self: Value) !Value {
const local = self.local;
const v8_context = local.handle;
const v8_isolate = local.isolate.handle;
+ const SerializerDelegate = struct {
+ // Called when V8 encounters a host object it doesn't know how to serialize.
+ // Returns false to indicate the object cannot be cloned, and throws a DataCloneError.
+ // V8 asserts has_exception() after this returns false, so we must throw here.
+ fn writeHostObject(_: ?*anyopaque, isolate: ?*v8.Isolate, _: ?*const v8.Object) callconv(.c) v8.MaybeBool {
+ const iso = isolate orelse return .{ .has_value = true, .value = false };
+ const message = v8.v8__String__NewFromUtf8(iso, "The object cannot be cloned.", v8.kNormal, -1);
+ const error_value = v8.v8__Exception__Error(message) orelse return .{ .has_value = true, .value = false };
+ _ = v8.v8__Isolate__ThrowException(iso, error_value);
+ return .{ .has_value = true, .value = false };
+ }
+
+ // Called by V8 to report serialization errors. The exception should already be thrown.
+ fn throwDataCloneError(_: ?*anyopaque, _: ?*const v8.String) callconv(.c) void {}
+ };
+
const size, const data = blk: {
- const serializer = v8.v8__ValueSerializer__New(v8_isolate, null) orelse return error.JsException;
+ const serializer = v8.v8__ValueSerializer__New(v8_isolate, &.{
+ .data = null,
+ .get_shared_array_buffer_id = null,
+ .write_host_object = SerializerDelegate.writeHostObject,
+ .throw_data_clone_error = SerializerDelegate.throwDataCloneError,
+ }) orelse return error.JsException;
+
defer v8.v8__ValueSerializer__DELETE(serializer);
var write_result: v8.MaybeBool = undefined;
diff --git a/src/browser/tests/window/window.html b/src/browser/tests/window/window.html
index 9623f1ef..e9e2e621 100644
--- a/src/browser/tests/window/window.html
+++ b/src/browser/tests/window/window.html
@@ -1,5 +1,6 @@
+