1 files changed, 48 insertions, 0 deletions
diff --git a/toolkit/components/thumbnails/test/browser_thumbnails_bg_destroy_browser.js b/toolkit/components/thumbnails/test/browser_thumbnails_bg_destroy_browser.js
new file mode 100644
index 0000000000..609d344972
--- /dev/null
+++ b/toolkit/components/thumbnails/test/browser_thumbnails_bg_destroy_browser.js
@@ -0,0 +1,48 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+add_task(async function thumbnails_bg_destroy_browser() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.ipc.processCount", 1]],
+  });
+
+  let url1 = "https://example.com/1";
+  ok(!thumbnailExists(url1), "First file should not exist yet.");
+
+  let url2 = "https://example.com/2";
+  ok(!thumbnailExists(url2), "Second file should not exist yet.");
+
+  let defaultTimeout = BackgroundPageThumbs._destroyBrowserTimeout;
+  BackgroundPageThumbs._destroyBrowserTimeout = 1000;
+
+  await bgCapture(url1);
+  ok(thumbnailExists(url1), "First file should exist after capture.");
+  removeThumbnail(url1);
+
+  // arbitrary wait - intermittent failures noted after 2 seconds
+  await TestUtils.waitForCondition(
+    () => {
+      return BackgroundPageThumbs._thumbBrowser === undefined;
+    },
+    "BackgroundPageThumbs._thumbBrowser should eventually be discarded.",
+    1000,
+    5
+  );
+
+  is(
+    BackgroundPageThumbs._thumbBrowser,
+    undefined,
+    "Thumb browser should be destroyed after timeout."
+  );
+  BackgroundPageThumbs._destroyBrowserTimeout = defaultTimeout;
+
+  await bgCapture(url2);
+  ok(thumbnailExists(url2), "Second file should exist after capture.");
+  removeThumbnail(url2);
+
+  isnot(
+    BackgroundPageThumbs._thumbBrowser,
+    undefined,
+    "Thumb browser should exist immediately after capture."
+  );
+});