Test your extension
Run unit tests against extension code with jest, or run the full extension server locally against the pub/sub emulator.
Test an extension with unit tests against its code, or by running the full extension server locally.
Unit tests with jest are the recommended approach
An action's logic is ordinary TypeScript, so test it like any other TypeScript: given this payload, does
it call onComplete with the right result, and does it call onError when the third-party call fails?
Write the onError case first. An action that only handles the happy path leaves care flows stuck when
the other system fails. See The onEvent function.
Run the full extension server when the wiring is the problem
To exercise the whole path, run the extension server application locally using the pub/sub emulator.
It catches wiring failures rather than logic errors: the action isn't being found, or the payload isn't the shape the action expects.
Next steps
Next: Deploy your extension.