Security

NoSQL Schema

Recommended schema is having the userId somewhere in the file path, and updating the Security Rules like so:

// Grants a user access to a node matching their user ID
service firebase.storage {
  match /b/{bucket}/o {
    // Files look like: "user/<UID>/path/to/file.txt"
    match /user/{userId}/{allPaths=**} {
      allow read, write: if request.auth.uid == userId;
    }
  }
}

Sub-collections

If you use something like {allPaths=**}, this also includes subcollections. If you have set up conditionals based on the response object, you will need to ensure that the condition exists at every level. For example:

// Grants a user access to a node matching their user ID
service firebase.firestore {
  match /document/{database}/tables {
    match /user/{userId}/{allPaths=**} {
      allow read, write: if response.data.role == "ADMIN";
    }
  }
}

This will expect even subcollections that matched with {allPaths=**} to have a field role. In order to get around this you want to set a full path:

// Grants a user access to a node matching their user ID
service firebase.firestore {
  match /document/{database}/tables {
    match /user/{userId}/{allPaths=**} {
      allow read, write: if get(/document/$(database)/tables/user/$(request.auth.uid)).data.role == "ADMIN";
    }
  }
}

https://medium.com/@khreniak/cloud-firestore-security-rules-basics-fac6b6bea18e

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