LunaMed UI User Machine: https://xstate.js.org/viz

machine.js

const userMachine = Machine({
  id: "user",
  
  initial: "noUser",
  
  states: {
    noUser: {
      invoke: {
        src: "getUser",
        onDone: "userFound",
        onError: [
          {
            cond: "userNotFound",
            target: "creatingUser",
          },
          {target: "error"},
        ]
      },
    },
    userFound: {
      type: "final",
    },
    creatingUser: {
      invoke: {
        src: "createUser",
        onDone: "userFound",
        onError: {
          target: "error",
        }
      }
    },
    error: {
      on: {
        RETRY: {
          target: "noUser",
        }
      }
    },
  },
}, {
  guards: {
    userNotFound: () => Math.random() > .5,
  }
})