admin/src/js/modules/sidebar.js

// Usage: https://github.com/Grsmto/simplebar
import SimpleBar from "simplebar";

const initialize = () => {
  initializeSimplebar();
  initializeSidebarCollapse();
}

const initializeSimplebar = () => {
  const simplebarElement = document.getElementsByClassName("js-simplebar")[0];

  if(simplebarElement){
    const simplebarInstance = new SimpleBar(document.getElementsByClassName("js-simplebar")[0]);

    /* Recalculate simplebar on sidebar dropdown toggle */
    const sidebarDropdowns = document.querySelectorAll(".js-sidebar [data-bs-parent]");
    
    sidebarDropdowns.forEach(link => {
      link.addEventListener("shown.bs.collapse", () => {
        simplebarInstance.recalculate();
      });
      link.addEventListener("hidden.bs.collapse", () => {
        simplebarInstance.recalculate();
      });
    });
  }
}

const initializeSidebarCollapse = () => {
  const sidebarElement = document.getElementsByClassName("js-sidebar")[0];
  const sidebarToggleElement = document.getElementsByClassName("js-sidebar-toggle")[0];

  if(sidebarElement && sidebarToggleElement) {
    sidebarToggleElement.addEventListener("click", () => {
      sidebarElement.classList.toggle("collapsed");

      sidebarElement.addEventListener("transitionend", () => {
        window.dispatchEvent(new Event("resize"));
      });
    });
  }
}

// Wait until page is loaded
document.addEventListener("DOMContentLoaded", () => initialize());