authelia/test/helpers/assertions/VerifyForwardedHeaderDoesNotExist.ts

import SeleniumWebDriver, { WebDriver } from "selenium-webdriver";
import Util from "util";

export default async function(driver: WebDriver, header: string, timeout: number = 5000) {
  const el = await driver.wait(SeleniumWebDriver.until.elementLocated(
    SeleniumWebDriver.By.tagName("body")), timeout);
  const text = await el.getText();

  const expectedLine = Util.format("\"%s\": ", header);
  if (text.indexOf(expectedLine) >= 0) {
    throw new Error("Header found.");
  }
}