1 files changed, 318 insertions, 0 deletions
diff --git a/toolkit/components/nimbus/test/unit/test_ExperimentAPI_ExperimentFeature.js b/toolkit/components/nimbus/test/unit/test_ExperimentAPI_ExperimentFeature.js
new file mode 100644
index 0000000000..f0aa2be521
--- /dev/null
+++ b/toolkit/components/nimbus/test/unit/test_ExperimentAPI_ExperimentFeature.js
@@ -0,0 +1,318 @@
+"use strict";
+
+const {
+  ExperimentAPI,
+  _ExperimentFeature: ExperimentFeature,
+} = ChromeUtils.import("resource://nimbus/ExperimentAPI.jsm");
+const { ExperimentFakes } = ChromeUtils.import(
+  "resource://testing-common/NimbusTestUtils.jsm"
+);
+
+async function setupForExperimentFeature() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  await manager.onStartup();
+
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+
+  return { sandbox, manager };
+}
+
+function setDefaultBranch(pref, value) {
+  let branch = Services.prefs.getDefaultBranch("");
+  branch.setStringPref(pref, value);
+}
+
+const TEST_FALLBACK_PREF = "testprefbranch.config";
+const FAKE_FEATURE_MANIFEST = {
+  description: "Test feature",
+  exposureDescription: "Used in tests",
+  variables: {
+    enabled: {
+      type: "boolean",
+      fallbackPref: "testprefbranch.enabled",
+    },
+    config: {
+      type: "json",
+      fallbackPref: TEST_FALLBACK_PREF,
+    },
+    remoteValue: {
+      type: "boolean",
+    },
+    test: {
+      type: "boolean",
+    },
+    title: {
+      type: "string",
+    },
+  },
+};
+
+/**
+ * FOG requires a little setup in order to test it
+ */
+add_setup(function test_setup() {
+  // FOG needs a profile directory to put its data in.
+  do_get_profile();
+
+  // FOG needs to be initialized in order for data to flow.
+  Services.fog.initializeFOG();
+});
+
+add_task(async function test_ExperimentFeature_test_helper_ready() {
+  const { manager } = await setupForExperimentFeature();
+  await manager.store.ready();
+
+  const featureInstance = new ExperimentFeature("foo", FAKE_FEATURE_MANIFEST);
+
+  await ExperimentFakes.enrollWithRollout(
+    {
+      featureId: "foo",
+      value: { remoteValue: "mochitest", enabled: true },
+    },
+    {
+      manager,
+    }
+  );
+
+  Assert.equal(
+    featureInstance.getVariable("remoteValue"),
+    "mochitest",
+    "set by remote config"
+  );
+});
+
+add_task(async function test_record_exposure_event() {
+  const { sandbox, manager } = await setupForExperimentFeature();
+
+  const featureInstance = new ExperimentFeature("foo", FAKE_FEATURE_MANIFEST);
+  const exposureSpy = sandbox.spy(ExperimentAPI, "recordExposureEvent");
+  const getExperimentSpy = sandbox.spy(ExperimentAPI, "getExperimentMetaData");
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+
+  // Clear any pre-existing data in Glean
+  Services.fog.testResetFOG();
+
+  featureInstance.recordExposureEvent();
+
+  Assert.ok(
+    exposureSpy.notCalled,
+    "should not emit an exposure event when no experiment is active"
+  );
+
+  // Check that there aren't any Glean exposure events yet
+  var exposureEvents = Glean.nimbusEvents.exposure.testGetValue();
+  Assert.equal(
+    undefined,
+    exposureEvents,
+    "no Glean exposure events before exposure"
+  );
+
+  await manager.store.addEnrollment(
+    ExperimentFakes.experiment("blah", {
+      branch: {
+        slug: "treatment",
+        features: [
+          {
+            featureId: "foo",
+            value: { enabled: false },
+          },
+        ],
+      },
+    })
+  );
+
+  featureInstance.recordExposureEvent();
+
+  Assert.ok(
+    exposureSpy.calledOnce,
+    "should emit an exposure event when there is an experiment"
+  );
+  Assert.equal(getExperimentSpy.callCount, 2, "Should be called every time");
+
+  // Check that the Glean exposure event was recorded.
+  exposureEvents = Glean.nimbusEvents.exposure.testGetValue();
+  // We expect only one event
+  Assert.equal(1, exposureEvents.length);
+  // And that one event matches the expected
+  Assert.equal(
+    "blah",
+    exposureEvents[0].extra.experiment,
+    "Glean.nimbusEvents.exposure recorded with correct experiment slug"
+  );
+  Assert.equal(
+    "treatment",
+    exposureEvents[0].extra.branch,
+    "Glean.nimbusEvents.exposure recorded with correct branch slug"
+  );
+  Assert.equal(
+    "foo",
+    exposureEvents[0].extra.feature_id,
+    "Glean.nimbusEvents.exposure recorded with correct feature id"
+  );
+
+  sandbox.restore();
+});
+
+add_task(async function test_record_exposure_event_once() {
+  const { sandbox, manager } = await setupForExperimentFeature();
+
+  const featureInstance = new ExperimentFeature("foo", FAKE_FEATURE_MANIFEST);
+  const exposureSpy = sandbox.spy(ExperimentAPI, "recordExposureEvent");
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+
+  // Clear any pre-existing data in Glean
+  Services.fog.testResetFOG();
+
+  await manager.store.addEnrollment(
+    ExperimentFakes.experiment("blah", {
+      branch: {
+        slug: "treatment",
+        features: [
+          {
+            featureId: "foo",
+            value: { enabled: false },
+          },
+        ],
+      },
+    })
+  );
+
+  featureInstance.recordExposureEvent({ once: true });
+  featureInstance.recordExposureEvent({ once: true });
+  featureInstance.recordExposureEvent({ once: true });
+
+  Assert.ok(
+    exposureSpy.calledOnce,
+    "Should emit a single exposure event when the once param is true."
+  );
+
+  // Check that the Glean exposure event was recorded.
+  let exposureEvents = Glean.nimbusEvents.exposure.testGetValue();
+  // We expect only one event
+  Assert.equal(1, exposureEvents.length);
+
+  sandbox.restore();
+});
+
+add_task(async function test_allow_multiple_exposure_events() {
+  const { sandbox, manager } = await setupForExperimentFeature();
+
+  const featureInstance = new ExperimentFeature("foo", FAKE_FEATURE_MANIFEST);
+  const exposureSpy = sandbox.spy(ExperimentAPI, "recordExposureEvent");
+
+  // Clear any pre-existing data in Glean
+  Services.fog.testResetFOG();
+
+  let doExperimentCleanup = await ExperimentFakes.enrollWithFeatureConfig(
+    {
+      featureId: "foo",
+      value: { enabled: false },
+    },
+    { manager }
+  );
+
+  featureInstance.recordExposureEvent();
+  featureInstance.recordExposureEvent();
+  featureInstance.recordExposureEvent();
+
+  Assert.ok(exposureSpy.called, "Should emit exposure event");
+  Assert.equal(
+    exposureSpy.callCount,
+    3,
+    "Should emit an exposure event for each function call"
+  );
+
+  // Check that the Glean exposure event was recorded.
+  let exposureEvents = Glean.nimbusEvents.exposure.testGetValue();
+  // We expect 3 events
+  Assert.equal(3, exposureEvents.length);
+
+  sandbox.restore();
+  await doExperimentCleanup();
+});
+
+add_task(async function test_onUpdate_before_store_ready() {
+  let sandbox = sinon.createSandbox();
+  const feature = new ExperimentFeature("foo", FAKE_FEATURE_MANIFEST);
+  const stub = sandbox.stub();
+  const manager = ExperimentFakes.manager();
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+  sandbox.stub(manager.store, "getAllActive").returns([
+    ExperimentFakes.experiment("foo-experiment", {
+      branch: {
+        slug: "control",
+        features: [
+          {
+            featureId: "foo",
+            value: null,
+          },
+        ],
+      },
+    }),
+  ]);
+
+  // We register for updates before the store finished loading experiments
+  // from disk
+  feature.onUpdate(stub);
+
+  await manager.onStartup();
+
+  Assert.ok(
+    stub.calledOnce,
+    "Called on startup after loading experiments from disk"
+  );
+  Assert.equal(
+    stub.firstCall.args[1],
+    "feature-experiment-loaded",
+    "Called for the expected reason"
+  );
+});
+
+add_task(async function test_ExperimentFeature_test_ready_late() {
+  const { manager, sandbox } = await setupForExperimentFeature();
+  const stub = sandbox.stub();
+
+  const featureInstance = new ExperimentFeature(
+    "test-feature",
+    FAKE_FEATURE_MANIFEST
+  );
+
+  const rollout = ExperimentFakes.rollout("foo", {
+    branch: {
+      slug: "slug",
+      features: [
+        {
+          featureId: featureInstance.featureId,
+          value: {
+            title: "hello",
+            enabled: true,
+          },
+        },
+      ],
+    },
+  });
+
+  sandbox.stub(manager.store, "getAllRollouts").returns([rollout]);
+
+  await manager.onStartup();
+
+  featureInstance.onUpdate(stub);
+
+  await featureInstance.ready();
+
+  Assert.ok(stub.notCalled, "We register too late to catch any events");
+
+  setDefaultBranch(TEST_FALLBACK_PREF, JSON.stringify({ foo: true }));
+
+  Assert.deepEqual(
+    featureInstance.getVariable("config"),
+    { foo: true },
+    "Feature is ready even when initialized after store update"
+  );
+  Assert.equal(
+    featureInstance.getVariable("title"),
+    "hello",
+    "Returns the NimbusTestUtils rollout default value"
+  );
+});