SUPERCILEX · October 4, 2017 04:24 · Oct 4, 2017
diff --git a/variables.rules b/variables.rules
@@ -0,0 +1,22 @@
+service cloud.firestore {
+  match /databases/{database}/documents {
+    // Incorrect solution
+    match /public/{doc=**} {
+      allow read;
+
+      match /foo/{bar} {
+        allow write: if doc == "foobar"; // Error! "doc" is a path object, not a string
+      }
+    }
+
+    // Correct solution
+    match /public/{doc} {
+      allow read;
+
+      match /foo/{bar} {
+        allow read;
+        allow write: if doc == "foobar"; // Correct, "doc" is now the document id
+      }
+    }
+  }
+}