Add code to test the wasm code path without actually dropping into wasm.

src/wasm/fixed_width_area.rs

@@ -9,7 +9,7 @@ use super::standard_properties::WasmStandardProperties;
 use super::to_wasm::ToWasm;
 use crate::wasm::to_wasm::ToWasmStandardProperties;
 
-#[derive(Serialize, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 #[serde(tag = "ast_node")]
 #[serde(rename = "org-data")]
 pub(crate) struct WasmFixedWidthArea<'s> {