AkashBabu/supervised-emitter

import {doesPatternMatch} from './pattern';

import {IMiddleware, IContext} from './interfaces';

/**
 * Creates a middleware which will be run
 * only when the pubEvent matches the given
 * pattern
 *
 * @param pattern Subscription event
 * @param middleware Middleware subscribed on the pattern
 */
export default function patternHandler(pattern: string, middleware: IMiddleware): IMiddleware {
  return (ctx: IContext) => {
    if (doesPatternMatch(ctx.pubEvent, pattern)) {
      return middleware(ctx);
    }

    return ctx.data;
  };
}