battled and won typings

This commit is contained in:
Ken
2019-01-31 11:21:05 -08:00
parent 578ad8221d
commit fceb24f985
5 changed files with 55 additions and 31 deletions

View File

@@ -1,9 +1,9 @@
import { Reducer } from 'redux';
import { ActionTypes, TodoAction } from '../actions';
import { ActionTypes, TodoAction, TodoActionLookup } from '../actions';
import { Draft, produce } from 'immer';
export type ImmerReducer<T> = (state: Draft<T>, action: TodoAction) => T;
export type HandlerMap<T> = { [actionType in ActionTypes]?: ImmerReducer<T> };
export type ImmerReducer<T, A = any> = (state: Draft<T>, action: A) => T;
export type HandlerMap<T> = { [actionType in ActionTypes]?: ImmerReducer<T, TodoActionLookup[actionType]> };
function isHandlerFunction<T>(handlerOrMap: HandlerMap<T> | ImmerReducer<T>): handlerOrMap is ImmerReducer<T> {
if (typeof handlerOrMap === 'function') {
@@ -13,12 +13,16 @@ function isHandlerFunction<T>(handlerOrMap: HandlerMap<T> | ImmerReducer<T>): ha
return false;
}
export function createReducer<T>(initialState: T, handlerOrMap: HandlerMap<T> | ImmerReducer<T>): Reducer<T> {
return function reducer(state = initialState, action: TodoAction): T {
export function createReducer<T, AType extends ActionTypes | never = never>(
initialState: T,
handlerOrMap: HandlerMap<T> | ImmerReducer<T, TodoActionLookup[AType]>
): Reducer<T> {
return function reducer(state = initialState, action: TodoAction | TodoActionLookup[AType]): T {
if (isHandlerFunction(handlerOrMap)) {
return produce(state, draft => handlerOrMap(draft, action));
return produce(state, draft => handlerOrMap(draft, action as TodoActionLookup[AType]));
} else if (handlerOrMap.hasOwnProperty(action.type)) {
return produce(state, draft => handlerOrMap[action.type](draft, action));
const handler = handlerOrMap[action.type] as ImmerReducer<T>;
return produce(state, draft => handler(draft, action));
} else {
return state;
}

View File

@@ -2,6 +2,7 @@ import { createReducer } from './createReducer';
import { Store, FilterTypes } from '../store';
import { combineReducers } from 'redux';
import produce from 'immer';
import { edit } from '../actions';
let counter = 0;
@@ -32,10 +33,15 @@ export const reducer = combineReducers<Store>({
}
});
return draft;
},
edit(draft, action) {
draft[action.id].label = action.label;
return draft;
}
}
),
filter: createReducer<Store['filter']>('all', (draft, action) => {
return action.filter;
filter: createReducer<Store['filter'], 'filter'>('all', (draft, action) => {
return action.filter as FilterTypes;
})
});