gecko-dev/netwerk/test/unit/test_header_Accept-Language_case.js

var testpath = "/bug1054739";

function run_test() {
  let intlPrefs = Cc["@mozilla.org/preferences-service;1"].getService(Ci.nsIPrefService).getBranch("intl.");

  let oldAcceptLangPref = intlPrefs.getCharPref("accept_languages");

  let testData = [
    ["en",              "en"],
    ["ast",             "ast"],
    ["fr-ca",           "fr-CA"],
    ["zh-yue",          "zh-yue"],
    ["az-latn",         "az-Latn"],
    ["sl-nedis",        "sl-nedis"],
    ["zh-hant-hk",      "zh-Hant-HK"],
    ["ZH-HANT-HK",      "zh-Hant-HK"],
    ["en-us-x-priv",    "en-US-x-priv"],
    ["en-us-x-twain",   "en-US-x-twain"],
    ["de, en-US, en",   "de,en-US;q=0.7,en;q=0.3"],
    ["de,en-us,en",     "de,en-US;q=0.7,en;q=0.3"],
    ["en-US, en",       "en-US,en;q=0.5"],
    ["EN-US;q=0.2, EN", "en-US,en;q=0.5"],
    ["en ;q=0.8, de  ", "en,de;q=0.5"],
    [",en,",            "en"],
  ];

  for (let i = 0; i < testData.length; i++) {
    let acceptLangPref = testData[i][0];
    let expectedHeader = testData[i][1];

    intlPrefs.setCharPref("accept_languages", acceptLangPref);
    let acceptLangHeader = setupChannel(testpath).getRequestHeader("Accept-Language");
    equal(acceptLangHeader, expectedHeader);
  }

  intlPrefs.setCharPref("accept_languages", oldAcceptLangPref);
}

function setupChannel(path) {
  let uri = NetUtil.newURI("http://localhost:4444" + path);
  let chan = NetUtil.newChannel({
    uri: uri,
    loadUsingSystemPrincipal: true
  });
  chan.QueryInterface(Ci.nsIHttpChannel);
  return chan;
}