Generated by XState Viz: https://xstate.js.org/viz

machine.js

const fetchMachine = Machine(
  {
    id: 'OAUTH CLIENT',
    type: 'parallel',
    context: {
      hasAuthorizationCode: true
    },
    states: {
      AUTHORIZED: {
        id: 'authed',
        initial: 'FALSE',
        states: {
          TRUE: {
            // on:
          },
          FALSE: {}
        }
      },
      CALLBACK: {
        initial: 'INIT',
        id: 'callback',
        states: {
          'INIT': {
            on: {
              '*': [
                {
                  target: 'REQUESTING ACCESS TOKEN',
                  cond: 'hasAuthorizationCode'
                },
                {
                  target: '#authed.FALSE'
                }
              ]
            }
          },
          'REQUESTING ACCESS TOKEN': {
            id: 'access_token',
            entry: 'exchangeAuthCodeForAccessToken',
            initial: 'idle',
            states: {
              idle: {
                on: {
                  FETCH: 'loading'
                }
              },
              loading: {
                on: {
                  RESOLVE: 'success',
                  REJECT: 'failure'
                }
              },
              success: {
                type: 'final',
                onEntry: send('SUCC'),
              },
              failure: {
                type: 'final',
                onEntry: send('FAIL'),
              }
            },
            on: {
              SUCC: 'REQUESTING SESSION',
              FAIL: '#authed.FALSE'
            }
          },
          'REQUESTING SESSION': {
            entry: 'exchangeAccessTokenForSession',
            on: {
              SUCC: {
                target: [
                  '#authed.TRUE',
                  'SESSION RECEIVED'
                ]
              },
              FAIL: '#authed.FALSE'
            }
          },
          'SESSION RECEIVED': {
            type: 'final',
          }
        }
      }
    }
  },
  { guards: { hasAuthorizationCode: ctx => ctx.hasAuthorizationCode } }
);