Function prepareEventNames

packages/zone.js/lib/common/events.ts:95–104

(eventName: string, eventNameToString?: (eventName: string) => string)

const IMMEDIATE_PROPAGATION_SYMBOL = zoneSymbol('propagationStopped');

function prepareEventNames(eventName: string, eventNameToString?: (eventName: string) => string) {
  const falseEventName = (eventNameToString ? eventNameToString(eventName) : eventName) + FALSE_STR;
  const trueEventName = (eventNameToString ? eventNameToString(eventName) : eventName) + TRUE_STR;
  const symbol = ZONE_SYMBOL_PREFIX + falseEventName;
  const symbolCapture = ZONE_SYMBOL_PREFIX + trueEventName;
  zoneSymbolEventNames[eventName] = {
    [FALSE_STR]: symbol,
    [TRUE_STR]: symbolCapture,
  };
}

export interface PatchEventTargetOptions {
  /**