diff --git a/testdata/compiled/interactive_1d_geo_brush.vg.json.svg b/testdata/compiled/interactive_1d_geo_brush.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/compiled/interactive_airport_crossfilter.vg.json.svg b/testdata/compiled/interactive_airport_crossfilter.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/lite/interactive_1d_geo_brush.vl.json.svg b/testdata/lite/interactive_1d_geo_brush.vl.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/lite/interactive_airport_crossfilter.vl.json.svg b/testdata/lite/interactive_airport_crossfilter.vl.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/clock.vg.json.svg b/testdata/vega/clock.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/hypothetical-outcome-plots.vg.json.svg b/testdata/vega/hypothetical-outcome-plots.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/pacman.vg.json.svg b/testdata/vega/pacman.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/platformer.vg.json.svg b/testdata/vega/platformer.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/watch.vg.json.svg b/testdata/vega/watch.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/testdata/vega/zoomable-circle-packing.vg.json.svg b/testdata/vega/zoomable-circle-packing.vg.json.svg
deleted file mode 100644
index e69de29..0000000
diff --git a/vegagoja_test.go b/vegagoja_test.go
index 4b5167e..51084da 100644
--- a/vegagoja_test.go
+++ b/vegagoja_test.go
@@ -89,8 +89,10 @@ func testRender(t *testing.T, ctx context.Context, testName, name string, timeou
 		t.Logf("---\n%s\n---", s)
 	}
 	t.Logf("duration: %s", total)
-	if err := os.WriteFile(name+".svg", []byte(s), 0o644); err != nil {
-		t.Fatalf("expected no error, got: %v", err)
+	if s = strings.TrimSpace(s); len(s) != 0 {
+		if err := os.WriteFile(name+".svg", []byte(s), 0o644); err != nil {
+			t.Fatalf("expected no error, got: %v", err)
+		}
 	}
 }