Identify Anemic State Machines
BOUNDARY-IDENTIFY-ANEMIC-STATE-MACHINES
Summary
Replace scattered booleans and conditionals with named states and transitions when lifecycle behavior is already complex. The move exposes illegal transitions and missing recovery paths without over-formalizing simple linear code.
Rule
Identify anemic state machines.
Why
Auth flows, UI state, async routing, setup wizards, and lifecycle code often hide a state machine inside booleans and scattered conditionals. Naming states and transitions exposes illegal transitions, missing recovery paths, and duplicated policy.
Helps
- Makes stateful behavior easier to test, extend, and reason about.
Limits
Do not introduce a formal state machine for simple linear code. Use it when transitions, invalid states, retries, or concurrent events are already making the code hard to follow.
Agent Instruction
Identify anemic state machines in auth flows, UI state, async routing, setup wizards, and lifecycle
code.Mechanisms
Supported by enums, transition functions, state diagrams, transition table tests, and error types for invalid transitions.