Immutable and type-checked state and actions for Redux (built on tcomb library)
import { createStore, applyMiddleware } from 'redux'
import t from 'tcomb'
import { createCheckedMiddleware, createCheckedReducer, createActionType } from 'redux-tcomb'
import createLogger from 'redux-logger'
// types
const State = t.Integer
const PositiveInteger = t.refinement(t.Integer, n => n >= 0, 'PositiveInteger')
const Action = createActionType({
INCREMENT: t.interface({ delta: PositiveInteger }),
DECREMENT: t.interface({ delta: PositiveInteger })
})
// reducer
function reducer(state = 0, action) {
switch(action.type) {
case 'INCREMENT' :
return state + action.delta
case 'DECREMENT' :
return state - action.delta
}
return state
}
// configure
const store = createStore(
createCheckedReducer(reducer, State),
applyMiddleware(
createCheckedMiddleware(Action),
createLogger()
)
)
// ok
store.dispatch({ type: 'INCREMENT', delta: 2 })
store.dispatch(Action.INCREMENT({ delta: 2 }))
// bad payload
store.dispatch({ type: 'INCREMENT', delta: -2 }) // throws [tcomb] Invalid value -2 supplied to Action(INCREMENT)/delta: PositiveInteger
// typo
store.dispatch({ type: 'INCRE', delta: 1 }) // throws [tcomb] Invalid value { "type": "INCRE", "delta": 1 } supplied to Action
type Reducer = (state: State, action: Action) => State;
createCheckedMiddleware(Action: Type) -> Function
createCheckedReducer(reducer: Reducer, State: Type) -> Reducer
createActionType(actions: {[key: string]: Type}) -> Type
The MIT License (MIT)