DeepSeek Native Setter Injector

Listens for postMessage events on chat.deepseek.com and logs them

// ==UserScript==
// @name        DeepSeek Native Setter Injector
// @description  Listens for postMessage events on chat.deepseek.com and logs them
// @match       https://chat.deepseek.com/*
// @version 0.0.1.20250803190221
// @namespace https://greasyfork.org/users/1435046
// ==/UserScript==

(function () {
  'use strict';

  // Cache the native setter for HTMLTextAreaElement.value
  const valueSetter = Object.getOwnPropertyDescriptor(
    HTMLTextAreaElement.prototype, 'value'
  ).set;

  window.addEventListener('message', event => {

    // find all primary filled buttons
    const buttons = document.querySelectorAll(
      'div[role="button"].ds-button--primary.ds-button--filled'
    );

    if (event.data && event.data.type === 'searchButtonClicked') {

      // click the one whose visible label is “Search”
      for (const btn of buttons) {
        if (btn.textContent.trim() === 'Search') {
          btn.click();
          break;
        }
      }
      return;
    }

    if (event.data && event.data.type === 'reasonButtonClicked') {

      // click the one whose visible label is “DeepThink (R1)”
      for (const btn of buttons) {
        if (btn.textContent.trim() === 'DeepThink (R1)') {
          btn.click();
          break;
        }
      }
      return;
    }

    if (event.data?.type === 'newChatButtonClicked') {
      document.querySelector('svg path[d^="M9.10999"]').closest('div').click();
      return;
    }

    let deepseekCssStyleId = document.getElementById('deepseekCssStyleId');

    let chatMessageInput = document.querySelector('div:has(> div > div > div > div > textarea[id="chat-input"])');
    let chatMessageInputRule = 'div:has(> div > div > div > div > textarea[id="chat-input"]) {display: none !important;}';

    let header = document.querySelector('div:has(> div > div > svg > path[d^="M23.7222 4H4.27776C3.57207 4"])');
    let headerRule = 'div:has(> div > div > svg > path[d^="M23.7222 4H4.27776C3.57207 4"]) {display: none !important;}';

    //if event data type is defaultChatMessageInputDisplay
    if (event.data?.type === 'defaultChatMessageInputDisplay') {
      console.log('default');
      if (chatMessageInput) {

        deepseekCssStyleId.innerHTML = deepseekCssStyleId.innerHTML.replace(`${chatMessageInputRule}`, '');

        deepseekCssStyleId.innerHTML = deepseekCssStyleId.innerHTML.replace(`${headerRule}`, '');


        //return
        return;
      }
    }

    if (event.data?.type === 'customizeChatMessageInputDisplay') {
      console.log('customize');
      if (chatMessageInput) {

        deepseekCssStyleId.innerHTML += `${chatMessageInputRule}`
        deepseekCssStyleId.innerHTML += `${headerRule}`


        //return
        return;
      }
    }

    if (event.data.type !== 'prompt') return;

    const textarea = document.getElementById('chat-input');
    if (!textarea) return;

    // 1. Update both DOM and React state without shifting focus
    valueSetter.call(textarea, event.data.content);

    // 2. Notify React/Vue/etc. of the change
    textarea.dispatchEvent(new InputEvent('input', { bubbles: true }));

    // 3. Click the send button if enabled and matching the icon path
    const sendBtn = document.querySelector('div[role="button"][aria-disabled="false"]');
    if (
      sendBtn &&
      sendBtn.querySelector('path[d^="M7 16c-.595 0-1.077-.462-1.077"]')
    ) {
      sendBtn.click();
    }

  });
})();