case 'CREATE_WORKOUTS' that returns workouts: [action.payload, ...state.workouts], raises " TypeError: e is null " when state.workouts is empty due to spread operator !
please add a if condition to avoid it , like below
case 'CREATE_WORKOUTS':
if (!state.workouts)
return {
workouts: [action.payload]
}
else
return {
workouts: [action.payload, ...state.workouts]
}