Method runGuards

core/src/components/router/router.tsx:326–354

* Executes the beforeLeave hook of the source route and the beforeEnter hook of the target route if they exist. * * When the beforeLeave hook does not return true (to allow navigating) then that value is returned early and the beforeEnter is executed. * Otherwise the beforeEnterHook hook of

(
    to: string[] | null = this.getSegments(),
    from?: string[] | null
  )

   * Otherwise the beforeEnterHook hook of the target route is executed.
   */
  private async runGuards(
    to: string[] | null = this.getSegments(),
    from?: string[] | null
  ): Promise<NavigationHookResult> {
    if (from === undefined) {
      from = parsePath(this.previousPath).segments;
    }

    if (!to || !from) {
      return true;
    }

    const routes = readRoutes(this.el);

    const fromChain = findChainForSegments(from, routes);
    // eslint-disable-next-line @typescript-eslint/prefer-optional-chain
    const beforeLeaveHook = fromChain && fromChain[fromChain.length - 1].beforeLeave;

    const canLeave = beforeLeaveHook ? await beforeLeaveHook() : true;
    if (canLeave === false || typeof canLeave === 'object') {
      return canLeave;
    }

    const toChain = findChainForSegments(to, routes);
    // eslint-disable-next-line @typescript-eslint/prefer-optional-chain
    const beforeEnterHook = toChain && toChain[toChain.length - 1].beforeEnter;

    return beforeEnterHook ? beforeEnterHook() : true;
  }

  private async writeNavState(
    node: HTMLElement | undefined,