1 files changed, 54 insertions, 0 deletions
diff --git a/toolkit/components/glean/tests/browser/browser_labeled_gifft.js b/toolkit/components/glean/tests/browser/browser_labeled_gifft.js
new file mode 100644
index 0000000000..676b59453e
--- /dev/null
+++ b/toolkit/components/glean/tests/browser/browser_labeled_gifft.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+function keyedScalarValue(aScalarName) {
+  let snapshot = Services.telemetry.getSnapshotForKeyedScalars();
+  return "parent" in snapshot ? snapshot.parent[aScalarName] : undefined;
+}
+
+add_task(async () => {
+  // Ensure we're starting with a clean slate. test-verify can be tricky.
+  Services.fog.testResetFOG();
+  Services.telemetry.clearScalars();
+
+  Assert.equal(
+    undefined,
+    Glean.testOnlyIpc.aLabeledCounter.a_label.testGetValue(),
+    "New labels with no values should return undefined"
+  );
+  Glean.testOnlyIpc.aLabeledCounter.a_label.add(1);
+  Glean.testOnlyIpc.aLabeledCounter.another_label.add(2);
+  Assert.equal(1, Glean.testOnlyIpc.aLabeledCounter.a_label.testGetValue());
+  Assert.equal(
+    2,
+    Glean.testOnlyIpc.aLabeledCounter.another_label.testGetValue()
+  );
+  // What about invalid/__other__?
+  Assert.equal(
+    undefined,
+    Glean.testOnlyIpc.aLabeledCounter.__other__.testGetValue()
+  );
+  Glean.testOnlyIpc.aLabeledCounter["1".repeat(72)].add(3);
+  Assert.throws(
+    () => Glean.testOnlyIpc.aLabeledCounter.__other__.testGetValue(),
+    /NS_ERROR_LOSS_OF_SIGNIFICANT_DATA/,
+    "Can't get the value when you're error'd"
+  );
+
+  let value = keyedScalarValue(
+    "telemetry.test.another_mirror_for_labeled_counter"
+  );
+  Assert.deepEqual(
+    {
+      a_label: 1,
+      another_label: 2,
+      ["1".repeat(72)]: 3,
+    },
+    value
+  );
+
+  // AND NOW, FOR THE TRUE TEST:
+  // Will this leak memory all over the place?
+});