Declarative Action Type

no-coupling-be-happy.js

// scoreboard-reducer.js
const INITIAL_STATE = {
  home: 0,
  away: 0,
}
export const scoreboardReducer = (state = INITIAL_STATE, action) {
  switch (action.type) {
    case 'GOAL_SCORED':
      const scoringSide = action.payload.team;
      return {...state, [scoringSide]: state.[scoringSide] + 1 };
    default:
      return state;
  }
}

// audience-reducer.ts
const INITIAL_STATE = 0; // represents audience excitement;
export const audienceExcitementReducer = (state = INITIAL_STATE, action) {
  switch (action.type) {
    case 'GOAL_SCORED':
      return state + 1; // audience gets more excited
    default:
      return state;
  }
}

// Some container component.js
export class Game extends React.Component {
  ....
  onGoal(scoringTeam) {
    this.props.dispatch({type: 'GOAL_SCORED', payload: {team: scoringTeam}});
  }
}