redeuceur

A utility for creating terse Redux reducers.

Install

$ npm install --save redeuceur

Usage

import redeuceur from 'redeuceur';

const initialState = {};

const handlers = [
  [
    // handle a single action type
    ActionTypes.CREATE_FOO,
    // return the next state
    (state, action) => action.foo,
  ],
  [
    // handle one of many action types
    [ ActionTypes.DELETE_FOO, ActionTypes.RESET_FOO, ],
    // return a static value
    {},
  ],
  [
    // handle an arbitrary condition
    (state, action) => action.type === ActionTypes.UPDATE_FOO && !state.isBar,
    // return a computed value
    (state, action) => Object.assign({}, state, action.foo),
  ],
];

const foo = redeuceur(initialState, ...handlers);

API

redeuceur(initialState, handler[,...])

Takes an initial state value and one or more handlers, and returns a Redux reducer.

initialState

Type: state

The reducer is initialized to the value of initialState.

handler

Type: Array

Every handler is a [condition, nextState] pair. A handler specifies when to change state (condition) and what change to make (nextState).

If no conditions are met, the reducer returns the last state. Thus, the default case is handled implicitly.

Handlers are evaluated in the order they are provided to redeuceur. The reducer returns the nextState value of the first match.

condition

Type: String, Array String, (state, action) -> Boolean

A string condition is met when the string strictly equals the action type.

An array condition is met when one string strictly equals the action type.

A function condition is met when condition(state, action) returns a truthy value.

nextState

Type: (state, action) -> state, state

If nextState is a function, the result of nextState(state, action) is returned as the next state. Otherwise, the value of nextState is returned.

License

MIT © Max Hallinan