Bug 1353722 - Catch errors when parsing preferences from filters and hiddenColumns r=rickychien

MozReview-Commit-ID: 6afGAHkT1rC

--HG--
extra : rebase_source : 422605aa2a3a2f5983e47c51037f0b73cf69e680

devtools/client/netmonitor/src/utils/create-store.js

@@ -17,15 +17,22 @@ const { TimingMarkers } = require("../reducers/timing-markers");
 const { UI, Columns } = require("../reducers/ui");
 
 function configureStore() {
+  const getPref = (pref) => {
+    try {
+      return JSON.parse(Services.prefs.getCharPref(pref));
+    } catch (_) {
+      return [];
+    }
+  };
+
   let activeFilters = {};
-  let filters = JSON.parse(Services.prefs.getCharPref("devtools.netmonitor.filters"));
+  let filters = getPref("devtools.netmonitor.filters");
   filters.forEach((filter) => {
     activeFilters[filter] = true;
   });
 
   let columns = new Columns();
-  let hiddenColumns =
-    JSON.parse(Services.prefs.getCharPref("devtools.netmonitor.hiddenColumns"));
+  let hiddenColumns = getPref("devtools.netmonitor.hiddenColumns");
 
   for (let [col] of columns) {
     columns = columns.withMutations((state) => {