why not use map?

[DiamondYuan]

why not use map

import { ActionCreator, AnyAction, isType } from 'typescript-fsa';

export type Handler<P> = (
  payload: P,
  sender: chrome.runtime.MessageSender,
  sendResponse: (response: any) => void
) => any;

interface Case<P> {
  actionCreator: ActionCreator<P>;
  handler: Handler<P>;
}

interface ListenerCombiner {
  case<P>(
    actionCreator: ActionCreator<P>,
    handler: Handler<P>
  ): ListenerCombiner;
}

export class MessageListenerCombiner implements ListenerCombiner {
  private cases: Map<string, Case<any>>;

  constructor() {
    this.cases = new Map();
  }

  case = <P>(actionCreator: ActionCreator<P>, handler: Handler<P>) => {
    this.cases.set(actionCreator.type, { actionCreator, handler });
    return this;
  };

  handle = (action: AnyAction, sender: any, sendResponse: any) => {
    const actionCase = this.cases.get(action.type);
    if (actionCase) {
      const { actionCreator, handler } = actionCase;
      if (isType(action, actionCreator)) {
        handler(action.payload, sender, sendResponse);
      }
    }
  };
}

[DiamondYuan]

https://github.com/dphilipson/typescript-fsa-reducers/blob/39038b4019b759e95f732d3d1edfc9bed5c22689/src/index.ts#L180

i think map.get is master than for loop

[dphilipson]

Very good catch, you're quite right. I'm not going to use a Map for the sake of unfortunate people in environments that don't have it (e.g. IE 10), but doing this with an object to look up makes good sense. Fixed in https://github.com/dphilipson/typescript-fsa-reducers/commit/7a681624db665e6371d7f7f30d4653ba255b7d27.