bulkrun.js

const sleep = (msec) => new Promise((resolve) => setTimeout(resolve, msec));

const sendButton = document.querySelector(
  `button[data-a-target="chat-send-button"]`
);

const send = (message) => {
  const input = document.querySelector(`textarea[data-a-target="chat-input"]`);
  const lastValue = input.value;
  input.value = message;
  const event = new Event("input", { bubbles: true });
  const tracker = input._valueTracker;
  if (tracker) {
    tracker.setValue(lastValue);
  }
  input.dispatchEvent(event);

  sendButton.click();
};

const init = () => {
  const button = sendButton.parentNode.cloneNode(true);
  button.querySelector(
    `[data-a-target="tw-core-button-label-text"]`
  ).innerText = "Bulk";
  button.addEventListener("click", async () => {
    const clipboard = await navigator.clipboard.readText();
    const run = confirm("以下のテキストを1行ずつ送信します:\n\n" + clipboard);
    if (!run) return;
    clipboard.split("\n").forEach(async (line) => {
      send(line);
      await sleep(1000);
    });
  });
  sendButton.parentNode.parentNode.appendChild(button);
};
init();