[scramjet] rewriter: fix optional postMessage access outputting invalid syntax

Author: velzie

packages/chrome/src/IsolatedFrame.tsx

@@ -487,7 +487,6 @@ const methods = {
 
 		const fetchresponse = await controller.fetchHandler.handleFetch(data);
 
-		console.log(fetchresponse.headers);
 		if (
 			isDownload(fetchresponse.headers, data.destination) &&
 			fetchresponse.status === 200

packages/rewriter_demo/src/main.js

@@ -41,7 +41,6 @@ setConfig({
 		scramitize: false,
 		sourcemaps: true,
 		destructureRewrites: true,
-		interceptDownloads: false,
 		allowInvalidJs: false,
 		allowFailedIntercepts: false,
 		antiAntiDebugger: false,

packages/scramjet/packages/core/rewriter/js/src/visitor.rs

@@ -470,9 +470,12 @@ where
 				// however this code only exists because of recaptcha whatever
 				// and it would slow down js execution a lot
 				if s.property.name == "postMessage" {
+					// include the "postMessage" and the dot before it in the inner span
+					// if `postMessage?.` remove the dot and the question mark
+					let offset = if s.optional { 1 } else { 2 };
+
 					self.jschanges.add(rewrite!(s.span, WrapPostMessage {
-						// include the "postMessage" and the dot before it (-1)
-						inner: Span::new(s.property.span.start - 1, s.property.span.end),
+						inner: Span::new(s.property.span.start - offset, s.property.span.end),
 					}));
 
 					// walk::walk_expression(self, &s.object);