The Tor Browser / file revision

 /* Any copyright is dedicated to the Public Domain.

  * http://creativecommons.org/publicdomain/zero/1.0/ */

 function runTests() {

   let url = "http://example.com/";

   let file = thumbnailFile(url);

   ok(!file.exists(), "Thumbnail file should not already exist.");

   let capturedURL = yield bgCaptureIfMissing(url);

   is(capturedURL, url, "Captured URL should be URL passed to capture");

   ok(file.exists(url), "Thumbnail should be cached after capture");

   let past = Date.now() - 1000000000;

   let pastFudge = past + 30000;

   file.lastModifiedTime = past;

   ok(file.lastModifiedTime < pastFudge, "Last modified time should stick!");

   capturedURL = yield bgCaptureIfMissing(url);

   is(capturedURL, url, "Captured URL should be URL passed to second capture");

   ok(file.exists(), "Thumbnail should remain cached after second capture");

   ok(file.lastModifiedTime < pastFudge,

      "File should not have been overwritten");

   file.remove(false);

 }