The Scenario
An enterprise e-commerce company is losing millions of dollars because their custom checkout flow has hidden bugs. Users are somehow clicking "Submit Payment" twice, or navigating to the "Success" page while the payment is still processing. You need to rewrite the checkout logic using a strict Finite State Machine.
The Brief
Design a Finite State Machine for a checkout flow. It must have states like `idle`, `validating_cart`, `processing_payment`, `success`, and `error`. You must define the exact events (transitions) that allow movement between these states. You can use a library like XState, or write a strict custom implementation.
Deliverables
- The state machine configuration (the states, events, and transitions)
- The logic that explicitly rejects invalid transitions (e.g., ignoring a "SUBMIT" event if currently in `processing_payment`)
- A short architectural defense of why Finite State Machines are better than boolean flags for critical flows
Submission Guidance
You do not need to build the UI, just the logic layer. Using XState syntax is highly recommended as it is the industry standard for this pattern.
Submit Your Work
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