The evaluation of Regex expressions in the blacklist is broken (#790)

* Fixed the blacklist's regex evaluation * Added logic to fix broken regular expressions * Replaced automatic regex fixing with helpful error message
igrigorik · Oct 9, 2021 · caacb45 · caacb45
1 parent f6fb427
commit caacb45
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Showing 3 changed files with 36 additions and 17 deletions.
diff --git a/inject.js b/inject.js
@@ -1,4 +1,5 @@
 var regStrip = /^[\r\t\f\v ]+|[\r\t\f\v ]+$/gm;
+var regEndsWithFlags = /\/(?!.*(.).*\1)[gimsuy]*$/;
 
 var tc = {
   settings: {
@@ -393,7 +394,17 @@ function isBlacklisted() {
 
     if (match.startsWith("/")) {
       try {
-        var regexp = new RegExp(match);
+        var parts = match.split("/");
+
+        if (regEndsWithFlags.test(match)) {
+          var flags = parts.pop();
+          var regex = parts.slice(1).join("/");
+        } else {
+          var flags = "";
+          var regex = match;
+        }
+
+        var regexp = new RegExp(regex, flags);
       } catch (err) {
         return;
       }

diff --git a/options.html b/options.html
@@ -167,7 +167,7 @@ <h3>Other</h3>
           <br />
           <em>
             <a href="https://www.regexpal.com/">Regex</a> is supported.<br />
-            Be sure it is in "//g" format.<br />
+            Be sure to use the literal notation.<br />
             ie: /(.+)youtube\.com(\/*)$/gi
           </em>
         </label>

diff --git a/options.js b/options.js
@@ -180,22 +180,30 @@ function createKeyBindings(item) {
 function validate() {
   var valid = true;
   var status = document.getElementById("status");
-  document
-    .getElementById("blacklist")
-    .value.split("\n")
-    .forEach((match) => {
-      match = match.replace(regStrip, "");
-      if (match.startsWith("/")) {
-        try {
-          var regexp = new RegExp(match);
-        } catch (err) {
-          status.textContent =
-            "Error: Invalid blacklist regex: " + match + ". Unable to save";
-          valid = false;
-          return;
-        }
+  var blacklist = document.getElementById("blacklist");
+
+  blacklist.value.split("\n").forEach((match) => {
+    match = match.replace(regStrip, "");
+
+    if (match.startsWith("/")) {
+      try {
+        var parts = match.split("/");
+
+        if (parts.length < 3)
+          throw "invalid regex";
+
+        var flags = parts.pop();
+        var regex = parts.slice(1).join("/");
+
+        var regexp = new RegExp(regex, flags);
+      } catch (err) {
+        status.textContent =
+          "Error: Invalid blacklist regex: \"" + match + "\". Unable to save. Try wrapping it in foward slashes.";
+        valid = false;
+        return;
       }
-    });
+    }
+  });
   return valid;
 }