feat: Convert helpers to use JS files

packages/backend/src/helpers/user-ability.js

@@ -0,0 +1,23 @@
+import {
+  PureAbility,
+  fieldPatternMatcher,
+  mongoQueryMatcher,
+} from '@casl/ability';
+
+// Must be kept in sync with `packages/web/src/helpers/userAbility.ts`!
+export default function userAbility(user) {
+  const permissions = user?.permissions;
+  const role = user?.role;
+
+  // We're not using mongo, but our fields, conditions match
+  const options = {
+    conditionsMatcher: mongoQueryMatcher,
+    fieldMatcher: fieldPatternMatcher,
+  };
+
+  if (!role || !permissions) {
+    return new PureAbility([], options);
+  }
+
+  return new PureAbility(permissions, options);
+}