t.Fatal(err)
		}
		got := b.String()
		if got != wantText {
			t.Errorf("\ngot  %q\nwant %q", got, wantText)
		}
	})
	t.Run("async", func(t *testing.T) {
		h := newAsyncHandler()
		if err := h.Handle(ctx, r); err != nil {
			t.Fatal(err)
		}
		got := h.ringBuffer[0]
		if !got.Time.Equal(r.Time) || !slices.EqualFunc(attrSlice(got), attrSlice(r), slog.Attr.Equal) {

	ctx := context.Background()
	for _, handler := range []struct {
		name     string
		h        slog.Handler
		skipRace bool
	}{
		{"disabled", disabledHandler{}, false},
		{"async discard", newAsyncHandler(), true},
		{"fastText discard", newFastTextHandler(io.Discard), false},
		{"Text discard", slog.NewTextHandler(io.Discard, nil), false},
		{"JSON discard", slog.NewJSONHandler(io.Discard, nil), false},
	} {

// arbitrary number of Records without either blocking or allocation.
type asyncHandler struct {
	ringBuffer [100]slog.Record
	next       int
}

func newAsyncHandler() *asyncHandler {
	return &asyncHandler{}
}

func (*asyncHandler) Enabled(context.Context, slog.Level) bool { return true }

func (h *asyncHandler) Handle(_ context.Context, r slog.Record) error {