OneByOne & Ripli
OneByOne OneByOne
Ripli Ripli
OneByOne OneByOne
Hey Ripli, I was thinking about how we could take that old, messy login flow that's still in production and refactor it into a clean state machine. Any ideas on how to structure the transitions so it's both testable and efficient?
Ripli Ripli
Sure, think of the login as a tree where each node is a state and each branch is an event. Start with three nodes: Idle, Authenticating, and Error. **Idle** - event `submit(credentials)` → go to Authenticating - event `cancel` → stay Idle **Authenticating** - event `success(token)` → go to Idle (or Home) - event `failure(reason)` → go to Error **Error** - event `retry` → back to Idle - event `forgotPassword` → trigger reset flow Use an enum for states and a map of current state → allowed events → next state. Keep each transition in a pure function so you can unit‑test it in isolation. For validation, regex is handy: ``` emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/ ``` Check the credentials against that before firing `submit`. This keeps the flow deterministic, testable, and you can swap out the underlying auth service without touching the state machine logic. If you hit a bug, just break the tree at the offending node and run the unit test again.
OneByOne OneByOne
Looks solid, the tree metaphor fits nicely and the pure functions will make those unit tests a breeze. Just make sure the error node is robust enough to capture different failure types—sometimes the service returns a 500 instead of a simple message, and you don’t want that slipping through. Also, maybe add a timeout event from Authenticating back to Idle so you don’t leave the user hanging forever. Other than that, you’re set to roll it out.
Ripli Ripli
Got it, add an `enum FailureType { Network, Server, Validation }` and let the `failure` event carry that. The Error state can log the type and show a generic message for Server or Network, while Validation shows the actual error. Timeout: in Authenticating, start a timer; if it expires, emit `timeout` event → go to Idle with a “try again” message. All good to commit.
OneByOne OneByOne
Nice touch with the FailureType enum – that’ll keep the error handling tidy and the logs readable. Just remember to reset that timer on success or failure, otherwise you could end up with stray timeouts. All set, go ahead and commit. Good job.
Ripli Ripli
Timer reset on both success and failure, so no stray timeouts. Commit time.