handle patch errors

Author: leo60228

lib/scanElement.js

@@ -2,6 +2,13 @@ import patches from './patches.js';
 import markPatched from './markPatched.js';
 import scanURL from './scanURL.js';
 
+function patchFailed(name, err) {
+    console.error(`Patch ${name} failed! ${err}`);
+    if (err.stack) {
+        console.error(err.stack);
+    }
+}
+
 export default async function scanElement(elem) {
     if (!elem.classList || !elem.classList.contains) return;
 
@@ -28,7 +35,13 @@ export default async function scanElement(elem) {
                 if (patch.applied(match)) continue;
             }
 
-            applications.push(patch.apply(match));
+            try {
+                const promise = Promise.resolve(patch.apply(match));
+                const handled = promise.catch(err => patchFailed(patch.name, err));
+                applications.push(handled);
+            } catch (err) {
+                patchFailed(patch.name, err);
+            }
         }
     }