gecko-dev/layout/style/test/browser_newtab_share_rule_processors.js

var theTab;
var theBrowser;

function listener(evt) {
  if (evt.target == theBrowser.contentDocument) {
    doTest();
  }
}

function test() {
  waitForExplicitFinish();
  var testURL = getRootDirectory(gTestPath) + "newtab_share_rule_processors.html";
  theTab = BrowserTestUtils.addTab(gBrowser, testURL);
  theBrowser = gBrowser.getBrowserForTab(theTab);
  theBrowser.addEventListener("load", listener, true);
}

function doTest() {
  theBrowser.removeEventListener("load", listener, true);
  var winUtils = theBrowser.contentWindow
    .QueryInterface(Ci.nsIInterfaceRequestor)
    .getInterface(Ci.nsIDOMWindowUtils);
  if (winUtils.isStyledByServo) {
    todo(false, "should update this test to check that Servo is also " +
                "correctly sharing CascadeData");
  } else {
    // The initial set of agent-level sheets should have a rule processor that's
    // also being used by another document.
    ok(winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AGENT_SHEET),
       "agent sheet rule processor is used by multiple style sets");
    // Document-level sheets currently never get shared rule processors.
    ok(!winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AUTHOR_SHEET),
       "author sheet rule processor is not used by multiple style sets");
    // Adding a unique style sheet to the agent level will cause it to have a
    // rule processor that is unique.
    theBrowser.contentWindow.wrappedJSObject.addAgentSheet();
    ok(!winUtils.hasRuleProcessorUsedByMultipleStyleSets(Ci.nsIStyleSheetService.AGENT_SHEET),
       "agent sheet rule processor is not used by multiple style sets after " +
       "having a unique sheet added to it");
  }
  gBrowser.removeTab(theTab);
  finish();
}