Fake typing in the console and executing commands, from the browser console

fake-typing-in-console-from-browser-console.js

// With the console open, in the browser console: 

async function getOpenedConsoleReference() {
  var {devtools} = Cu.import("resource://devtools/shared/Loader.jsm", {});
  var target = await devtools.TargetFactory.forTab(gBrowser.selectedTab);
  var {gDevTools} = devtools.require("devtools/client/framework/devtools");
  var toolbox = gDevTools.getToolbox(target);
  return toolbox.getCurrentPanel();
}

function sleep(delay) { 
  return new Promise(res => setTimeout(res, delay));
}

async function typeInConsole(inputs, {
  WAIT_BEFORE_TYPING_MS = 1000, 
  WAIT_BETWEEN_KEYSTROKES = 50, 
  WAIT_BEFORE_EXECUTE = 200, 
  WAIT_AFTER_EXECUTE = 1000
} = {}) {
  const {hud} = await getOpenedConsoleReference();
  hud.ui.clearOutput();
  await sleep(WAIT_BEFORE_TYPING_MS);
  hud.jsterm._setValue("");
  for(const input of inputs) {
    for (const char of Array.from(input)) {
      hud.jsterm.insertStringAtCursor(char);
      await sleep(WAIT_BETWEEN_KEYSTROKES);
    }
    await sleep(WAIT_BEFORE_EXECUTE);
    hud.jsterm.execute();
    await sleep(WAIT_AFTER_EXECUTE);
  }
}

typeInConsole([
  `1 + 1`,
  `$_`,
  `$_ + 1`
]);