Moved external licenses check into response pre-processing, in order to avoid filterResponse() as much as possible (fixing issue #11)

3 files changed, 36 insertions, 31 deletions

diff --git a/bg/ResponseProcessor.js b/bg/ResponseProcessor.js
index 7c264a4..e3d6c45 100644
--- a/bg/ResponseProcessor.js
+++ b/bg/ResponseProcessor.js
@@ -33,8 +33,8 @@ class ResponseProcessor {
 
   static install(handler, types = ["main_frame", "sub_frame", "script"]) {
     if (listeners.has(handler)) return false;
-    let listener =
-      request =>  new ResponseTextFilter(request).process(handler);
+    let listener = 
+      async request =>  await new ResponseTextFilter(request).process(handler);
     listeners.set(handler, listener);
     webRequestEvent.addListener(
   		listener,
@@ -70,12 +70,12 @@ class ResponseTextFilter {
       (type === "script" || /\bhtml\b/i.test(md.contentType));
   }
 
-  process(handler) {
+  async process(handler) {
     if (!this.canProcess) return ResponseProcessor.ACCEPT;
     let {metaData, request} = this;
     let response = {request, metaData}; // we keep it around allowing callbacks to store state
     if (typeof handler.pre === "function") {
-      let res = handler.pre(response);
+      let res = await handler.pre(response);
       if (res) return res;
       if (handler.post) handler = handler.post;
       if (typeof handler !== "function") ResponseProcessor.ACCEPT;
@@ -101,7 +101,7 @@ class ResponseTextFilter {
       } catch(e) {
         console.error(e);
       }
-      if (metaData.forcedUTF8 ||
+      if (metaData.forcedUTF8 && request.type !== "script" ||
         editedText !== null && response.text !== editedText) {
         // if we changed the charset, the text or both, let's re-encode
         filter.write(new TextEncoder().encode(editedText));
diff --git a/content/externalLicenseChecker.js b/content/externalLicenseChecker.js
index 89f871f..f150cea 100644
--- a/content/externalLicenseChecker.js
+++ b/content/externalLicenseChecker.js
@@ -79,9 +79,13 @@
   }
 
   browser.runtime.onMessage.addListener(async m => {
-    if (m.action in handlers) {
+    if (m.action in handlers) try {
       debug("Received message", m);
-      return await handlers[m.action](m);
+      let result =  await handlers[m.action](m);
+      console.debug("Returning", result);
+      return result;
+    } catch (e) {
+      console.error(e);
     }
   });
 }
diff --git a/main_background.js b/main_background.js
index 0737926..a521d22 100644
--- a/main_background.js
+++ b/main_background.js
@@ -853,9 +853,9 @@ var ResponseHandler = {
 	/**
 	*	Enforce white/black lists for url/site early (hashes will be handled later)
 	*/
-	pre(response) {
+	async pre(response) {
 		let {request} = response;
-		let {url, type, tabId} = request;
+		let {url, type, tabId, frameId} = request;
 		
 		url = ListStore.urlItem(url);
 		let site = ListStore.siteItem(url);
@@ -878,15 +878,31 @@ var ResponseHandler = {
 			});
 		} else {
 			let whitelistedSite = whitelist.contains(site);
-			if ((response.whitelisted = (whitelistedSite || whitelist.contains(url)))
-					&& type === "script") {
-				// accept the script and stop processing
-				addReportEntry(tabId, url, {url: topUrl, 
-					"whitelisted": [url, whitelistedSite ? `User whitelisted ${site}` : "Whitelisted by user"]});
-				return ResponseProcessor.ACCEPT;
+			let whitelisted = response.whitelisted = whitelistedSite || whitelist.contains(url);
+			if (type === "script") {
+				if (whitelisted) {
+					// accept the script and stop processing
+					addReportEntry(tabId, url, {url: topUrl, 
+						"whitelisted": [url, whitelistedSite ? `User whitelisted ${site}` : "Whitelisted by user"]});
+					return ResponseProcessor.ACCEPT;
+				} else {
+					let scriptInfo = await ExternalLicenses.check({url, tabId, frameId});
+					if (scriptInfo) {
+						let verdict, ret;
+						let msg = scriptInfo.toString();
+						if (scriptInfo.allFree) {
+							verdict = "accepted";
+							ret = ResponseProcessor.ACCEPT;
+						} else {
+							verdict = "blocked";
+							ret = ResponseProcessor.REJECT;
+						}
+						addReportEntry(tabId, url, {url, [verdict]: [url, msg]});
+						return ret;
+					}
+				}
 			}
 		}
-		
 		// it's a page (it's too early to report) or an unknown script:
 		//  let's keep processing
 		return ResponseProcessor.CONTINUE;
@@ -909,21 +925,6 @@ async function handle_script(response, whitelisted){
 	let {text, request} = response;
 	let {url, tabId, frameId} = request;
 	url = ListStore.urlItem(url);
-	if (!whitelisted) {
-		let scriptInfo = await ExternalLicenses.check({url, tabId, frameId});
-		if (scriptInfo) {
-			let verdict;
-			let msg = scriptInfo.toString();
-			if (scriptInfo.allFree) {
-				verdict = "accepted";
-			} else {
-				verdict = "blocked";
-				text = `/* ${msg} */`;
-			}
-			addReportEntry(tabId, url, {url, [verdict]: [url, msg]});
-			return text;
-		}
-	}
   let edited = await get_script(text, url, tabId, whitelisted, -2);
 	return Array.isArray(edited) ? edited[0] : edited;
 }