Output useful debug info from Flux dispatch decorator

dispatch_decorator_debug.js

const groupStyle = 'font-weight: normal; color: gray';
const stackStyle = 'color: gray';

function dispatchDecoratorFactory( ACTION ) {
  return function dispatchDecorator( target, key, descriptor ) {
    const fn = descriptor.value;
    descriptor.value = function decoratedMethod( ...args ) {
      if ( myModeFlag === 'debug' ) {
        console.groupCollapsed( `%c${target.constructor.name}.${key}(%O) -> ${ACTION}`, groupStyle, args );
        console.debug( `%c${( new Error() ).stack}`, stackStyle );
        console.groupEnd(); 
      }
      // ...do the rest of your dispatch logic
    }
  }
}