Bug 1910470 - Support value extra GIFFT mapping in Glean C++ API r=TravisLong

Differential Revision: https://phabricator.services.mozilla.com/D218013

toolkit/components/glean/bindings/private/Event.h

@@ -63,17 +63,22 @@ class EventMetric {
       // twice the required allocation. We could be smarter and reuse the data.
       // But this is GIFFT-only allocation, so wait to be told it's a problem.
       Maybe<CopyableTArray<Telemetry::EventExtraEntry>> telExtras;
+      Maybe<nsCString> telValue;
       if (aExtras) {
         CopyableTArray<Telemetry::EventExtraEntry> extras;
         auto serializedExtras = aExtras->ToFfiExtra();
         auto keys = std::move(std::get<0>(serializedExtras));
         auto values = std::move(std::get<1>(serializedExtras));
         for (size_t i = 0; i < keys.Length(); i++) {
+          if (keys[i].EqualsLiteral("value")) {
+            telValue = Some(values[i]);
+            continue;
+          }
           extras.EmplaceBack(Telemetry::EventExtraEntry{keys[i], values[i]});
         }
         telExtras = Some(extras);
       }
-      Telemetry::RecordEvent(id.extract(), Nothing(), telExtras);
+      Telemetry::RecordEvent(id.extract(), telValue, telExtras);
     }
     if (aExtras) {
       auto extra = aExtras->ToFfiExtra();

toolkit/components/telemetry/tests/gtest/TestEvents.cpp

@@ -10,6 +10,8 @@
 #include "mozilla/Maybe.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/Unused.h"
+#include "mozilla/glean/fog_ffi_generated.h"
+#include "mozilla/glean/GleanMetrics.h"
 #include "TelemetryFixture.h"
 #include "TelemetryTestHelpers.h"
 
@@ -113,3 +115,67 @@ TEST_F(TelemetryTestFixture, RecordEventNative) {
   ASSERT_EQ(NS_ConvertUTF16toUTF8(jsStr).Length(), (uint32_t)80)
       << "Extra must have been truncated to 80 bytes.";
 }
+
+using mozilla::Some;
+using mozilla::glean::test_only_ipc::AnEventExtra;
+// Test that we get a mirrored value from the C++ Glean API.
+TEST_F(TelemetryTestFixture, GIFFTValue) {
+  // Reset FOG to clear the stores.
+  const nsCString empty;
+  mozilla::glean::impl::fog_test_reset(&empty, &empty);
+
+  // Make sure we don't get events from other tests.
+  Unused << mTelemetry->ClearEvents();
+
+  // Enable recording of telemetry.test events.
+  const nsCString category("telemetry.test");
+  const nsCString method("mirror_with_extra");
+  const nsCString object("object1");
+  Telemetry::SetEventRecordingEnabled(category, true);
+
+  // Record in Glean.
+  // We include an extra extra key (extra1, here) to ensure there's always six
+  // items in the record array.
+  AnEventExtra extra = {
+      .extra1 = Some("a"_ns),
+      .value = Some("some value"_ns),
+  };
+  mozilla::glean::test_only_ipc::an_event.Record(Some(extra));
+  auto optEvents =
+      mozilla::glean::test_only_ipc::an_event.TestGetValue().unwrap();
+  ASSERT_TRUE(optEvents.isSome())
+  << "There are Glean events.";
+  auto events = optEvents.extract();
+  ASSERT_EQ(1UL, events.Length()) << "There is exactly one Glean event.";
+
+  // Assert in Telemetry.
+  AutoJSContextWithGlobal cx(mCleanGlobal);
+  JS::Rooted<JS::Value> eventsSnapshot(cx.GetJSContext());
+  GetEventSnapshot(cx.GetJSContext(), &eventsSnapshot);
+
+  ASSERT_TRUE(
+      EventPresent(cx.GetJSContext(), eventsSnapshot, category, method, object))
+  << "Test event must be present.";
+
+  // Ensure that the `value` value was mapped appropriately.
+  JSContext* aCx = cx.GetJSContext();
+  JS::Rooted<JSObject*> arrayObj(aCx, &eventsSnapshot.toObject());
+  JS::Rooted<JS::Value> eventRecord(aCx);
+  ASSERT_TRUE(JS_GetElement(aCx, arrayObj, 0, &eventRecord))
+  << "Must be able to get record.";
+  JS::Rooted<JSObject*> recordArray(aCx, &eventRecord.toObject());
+  uint32_t recordLength;
+  ASSERT_TRUE(JS::GetArrayLength(aCx, recordArray, &recordLength))
+  << "Event record array must have length.";
+  ASSERT_EQ(6UL, recordLength) << "Event record array must have 6 elements.";
+
+  JS::Rooted<JS::Value> str(aCx);
+  nsAutoJSString jsStr;
+  // The value string is at index 4
+  ASSERT_TRUE(JS_GetElement(aCx, recordArray, 4, &str))
+  << "Must be able to get value.";
+  ASSERT_TRUE(jsStr.init(aCx, str))
+  << "Value must be able to be init'd to a jsstring.";
+  ASSERT_STREQ(NS_ConvertUTF16toUTF8(jsStr).get(), "some value")
+      << "The value of the value must be 'some value'";
+}