rules_version = '2';

service cloud.firestore {

// Determine if the value of the field "key" is the same

// before and after the request.

function unchanged(key) {

return (key in resource.data)

&& (key in request.resource.data)

&& (resource.data[key] == request.resource.data[key]);

}

match /databases/{database}/documents {

// Restaurants:

// - Authenticated user can read

// - Authenticated user can create/update (for demo purposes only)

// - Updates are allowed if no fields are added and name is unchanged

// - Deletes are not allowed (default)

match /restaurants/{restaurantId} {

allow read: if request.auth != null;

allow create: if request.auth != null;

allow update: if request.auth != null

&& (request.resource.data.keys() == resource.data.keys())

&& unchanged("name");

// Ratings:

// - Authenticated user can read

// - Authenticated user can create if userId matches

// - Deletes and updates are not allowed (default)

match /ratings/{ratingId} {

allow read: if request.auth != null;

allow create: if request.auth != null

&& request.resource.data.userId == request.auth.uid;

}

}

}

}