1 files changed, 69 insertions, 0 deletions
diff --git a/dom/localstorage/test/unit/test_usage.js b/dom/localstorage/test/unit/test_usage.js
new file mode 100644
index 0000000000..552a45e4a6
--- /dev/null
+++ b/dom/localstorage/test/unit/test_usage.js
@@ -0,0 +1,69 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+add_task(async function testSteps() {
+  const data = {};
+  data.key = "key1";
+  data.value = "value1";
+  data.usage = data.key.length + data.value.length;
+
+  const principal = getPrincipal("http://example.com");
+
+  info("Setting prefs");
+
+  Services.prefs.setBoolPref(
+    "dom.storage.enable_unsupported_legacy_implementation",
+    false
+  );
+
+  info("Stage 1 - Testing usage after adding item");
+
+  info("Getting storage");
+
+  let storage = getLocalStorage(principal);
+
+  info("Adding item");
+
+  storage.setItem(data.key, data.value);
+
+  info("Resetting origin");
+
+  let request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, data.usage, "Correct usage");
+
+  info("Resetting");
+
+  request = reset();
+  await requestFinished(request);
+
+  info("Stage 2 - Testing usage after removing item");
+
+  info("Getting storage");
+
+  storage = getLocalStorage(principal);
+
+  info("Removing item");
+
+  storage.removeItem(data.key);
+
+  info("Resetting origin");
+
+  request = resetOrigin(principal);
+  await requestFinished(request);
+
+  info("Getting usage");
+
+  request = getOriginUsage(principal);
+  await requestFinished(request);
+
+  is(request.result.usage, 0, "Correct usage");
+});