Overview

#136 Moved common MongoDB logic to the @powersync/lib-service-mongodb package.

The bucket storage module's MongoDB connection is created using a utility from the shared library. The storage implementation checks certain caught Errors if they are instances of the MongoDB MongoServerError class. The instanceof checks fail if the shared library and the storage module use different versions of the MongoDB package. The core repository uses the same version throughout, but the hosted version's lockfile resolved different versions which caused the error detection to fail. Luckily the affected processes are retried, which did not cause any major issues.

This PR addresses the issue via two methods.

A isMongoServerError utility function is now exported from @powersync/lib-service-mongodb. The instanceof check in this function should pass if the connection was created from the shared library. Additionally a fallback check is added by checking the Error prototype name field - this should detect the error type even if a different MongoDB package spawned the connection or error.

The direct mongodb NPM package dependency has been removed from the MongoDB replicator and storage modules. The shared MongoDB library now re-exports it's mongodb dependency.

Testing

Development packages were released and locally installed in the hosted repository. A sync rule change was applied which triggered the termination of previous sync rules. Sync rules were correctly terminated with no error logs.

Before:

After:

The MongoDB replicator was also smoke tested locally.