もう addEventListener しなくて良い...!!

0_clipboard.html

<div data-controller="clipboard">
  <button data-action="click->clipboard#copy" type="button" data-clipboard-target="value" data-copy="some copy text"></button>
  <div data-clipboard-target="tooltip" role="tooltip" class="absolute z-10 invisible inline-block px-3 py-2 text-sm font-medium text-white transition-opacity duration-300 bg-gray-900 rounded-lg shadow-sm opacity-0 tooltip dark:bg-gray-700">
    Copied!
    <div class="tooltip-arrow" data-popper-arrow></div>
  </div>
</div>

1_main.ts

declare global {
  interface Window {
    Stimulus: any
  }
}

import { Application } from "@hotwired/stimulus"

import ClipboardController from './controllers/clipboard_controller'

window.Stimulus = Application.start()
window.Stimulus.register("clipboard", ClipboardController)

2_clipboard_controller.ts

import { Controller, Context } from '@hotwired/stimulus'
import { Tooltip } from 'flowbite';

export default class ClipboardController extends Controller {
  static targets = [ 'value', 'tooltip' ]

  declare readonly valueTarget: HTMLInputElement
  declare readonly tooltipTarget: HTMLElement
  declare readonly tooltip: Tooltip

  constructor(context: Context) {
    super(context)
    this.tooltip = new Tooltip(this.tooltipTarget, this.valueTarget, {
      placement: 'top',
      triggerType: 'none',
    })
  }

  copy() {
    navigator.clipboard.writeText(this.value).then(() => {
      this.tooltip.show();
      setTimeout(function () {
        this.tooltip.hide();
      }, 1000);
    });
  }

  get value() {
    return this.valueTarget.dataset.copy
  }
}

4_before.ts

// 移行前のコード

import { documentReady } from 'html-ready';
import { Tooltip } from 'flowbite';

documentReady.then(() => {
  document.querySelectorAll(".js-text-copy").forEach((element: HTMLInputElement) => {
    const text = element.dataset.copy;
    const target = document.getElementById(element.dataset.target);
    const tooltip = new Tooltip(target, element, {
      placement: 'top',
      triggerType: 'none',
    });
    element.addEventListener("click", (e) => {
      navigator.clipboard.writeText(text).then(() => {
        tooltip.show();
        setTimeout(function () {
          tooltip.hide();
        }, 1000);
      });
    });
  });
});