background.js

chrome.runtime.onInstalled.addListener(() => {
  chrome.action.setBadgeText({
    text: 'OFF',
  });
});
const extensions = 'https://developer.chrome.com/docs/extensions';
const webstore = 'https://developer.chrome.com/docs/webstore';

chrome.action.onClicked.addListener(async (tab) => {
  const prevState = await chrome.action.getBadgeText({ tabId: tab.id });
  // Next state will always be the opposite
  const nextState = prevState === 'ON' ? 'OFF' : 'ON';

  // Set the action badge to the next state
  await chrome.action.setBadgeText({
    tabId: tab.id,
    text: nextState,
  });
  if (nextState === 'ON') {
    chrome.scripting.executeScript({
      target: {
        tabId: tab.id,
      },
      func: () => {
        document.addEventListener(
          'selectionchange',
          handleOnSelectionChange
        );
      },
    });
  } else if (nextState === 'OFF') {
    chrome.scripting.executeScript({
      target: {
        tabId: tab.id,
      },
      func: () => {
        document.removeEventListener(
          'selectionchange',
          handleOnSelectionChange
        );
      },
    });
  }
});