gecko-dev/xpinstall/tests/browser_opendialog.js

// Load in the test harness
var scriptLoader = Components.classes["@mozilla.org/moz/jssubscript-loader;1"]
                             .getService(Components.interfaces.mozIJSSubScriptLoader);

var rootDir = getRootDirectory(window.location.href);
scriptLoader.loadSubScript(rootDir + "harness.js", this);

// ----------------------------------------------------------------------------
// Test whether an install succeeds when the progress dialog is already open.
function test() {
  Harness.installEndedCallback = check_xpi_install;
  Harness.installsCompletedCallback = finish_test;
  Harness.setup();

  window.openDialog("chrome://mozapps/content/extensions/extensions.xul", "",
                    "chrome,menubar,extra-chrome,toolbar,dialog=no,resizable");

  var pm = Services.perms;
  pm.add(makeURI("http://example.com/"), "install", pm.ALLOW_ACTION);

  var triggers = encodeURIComponent(JSON.stringify({
    "Unsigned XPI": TESTROOT + "unsigned.xpi"
  }));
  gBrowser.selectedTab = gBrowser.addTab();
  gBrowser.loadURI(TESTROOT + "installtrigger.html?" + triggers);
}

function check_xpi_install(addon, status) {
  is(status, 0, "Install should succeed");
}

function finish_test() {
  var em = Components.classes["@mozilla.org/extensions/manager;1"]
                     .getService(Components.interfaces.nsIExtensionManager);
  em.cancelInstallItem("unsigned-xpi@tests.mozilla.org");

  Services.perms.remove("example.com", "install");

  gBrowser.removeCurrentTab();
  Harness.finish();
}