1 files changed, 578 insertions, 0 deletions
diff --git a/toolkit/components/nimbus/test/unit/test_ExperimentAPI.js b/toolkit/components/nimbus/test/unit/test_ExperimentAPI.js
new file mode 100644
index 0000000000..1166f99976
--- /dev/null
+++ b/toolkit/components/nimbus/test/unit/test_ExperimentAPI.js
@@ -0,0 +1,578 @@
+"use strict";
+
+const { ExperimentAPI } = ChromeUtils.import(
+  "resource://nimbus/ExperimentAPI.jsm"
+);
+const { ExperimentFakes } = ChromeUtils.import(
+  "resource://testing-common/NimbusTestUtils.jsm"
+);
+const { TestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/TestUtils.sys.mjs"
+);
+const COLLECTION_ID_PREF = "messaging-system.rsexperimentloader.collection_id";
+
+/**
+ * #getExperiment
+ */
+add_task(async function test_getExperiment_fromChild_slug() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  const expected = ExperimentFakes.experiment("foo");
+
+  await manager.onStartup();
+
+  sandbox.stub(ExperimentAPI, "_store").get(() => ExperimentFakes.childStore());
+
+  await manager.store.addEnrollment(expected);
+
+  // Wait to sync to child
+  await TestUtils.waitForCondition(
+    () => ExperimentAPI.getExperiment({ slug: "foo" }),
+    "Wait for child to sync"
+  );
+
+  Assert.equal(
+    ExperimentAPI.getExperiment({ slug: "foo" }).slug,
+    expected.slug,
+    "should return an experiment by slug"
+  );
+
+  Assert.deepEqual(
+    ExperimentAPI.getExperiment({ slug: "foo" }).branch,
+    expected.branch,
+    "should return the right branch by slug"
+  );
+
+  sandbox.restore();
+});
+
+add_task(async function test_getExperiment_fromParent_slug() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  const expected = ExperimentFakes.experiment("foo");
+
+  await manager.onStartup();
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+  await ExperimentAPI.ready();
+
+  await manager.store.addEnrollment(expected);
+
+  Assert.equal(
+    ExperimentAPI.getExperiment({ slug: "foo" }).slug,
+    expected.slug,
+    "should return an experiment by slug"
+  );
+
+  sandbox.restore();
+});
+
+add_task(async function test_getExperimentMetaData() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  const expected = ExperimentFakes.experiment("foo");
+  let exposureStub = sandbox.stub(ExperimentAPI, "recordExposureEvent");
+
+  await manager.onStartup();
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+  await ExperimentAPI.ready();
+
+  await manager.store.addEnrollment(expected);
+
+  let metadata = ExperimentAPI.getExperimentMetaData({ slug: expected.slug });
+
+  Assert.equal(
+    Object.keys(metadata.branch).length,
+    1,
+    "Should only expose one property"
+  );
+  Assert.equal(
+    metadata.branch.slug,
+    expected.branch.slug,
+    "Should have the slug prop"
+  );
+
+  Assert.ok(exposureStub.notCalled, "Not called for this method");
+
+  sandbox.restore();
+});
+
+add_task(async function test_getRolloutMetaData() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  const expected = ExperimentFakes.rollout("foo");
+  let exposureStub = sandbox.stub(ExperimentAPI, "recordExposureEvent");
+
+  await manager.onStartup();
+  sandbox.stub(ExperimentAPI, "_store").get(() => manager.store);
+  await ExperimentAPI.ready();
+
+  await manager.store.addEnrollment(expected);
+
+  let metadata = ExperimentAPI.getExperimentMetaData({ slug: expected.slug });
+
+  Assert.equal(
+    Object.keys(metadata.branch).length,
+    1,
+    "Should only expose one property"
+  );
+  Assert.equal(
+    metadata.branch.slug,
+    expected.branch.slug,
+    "Should have the slug prop"
+  );
+
+  Assert.ok(exposureStub.notCalled, "Not called for this method");
+
+  sandbox.restore();
+});
+
+add_task(function test_getExperimentMetaData_safe() {
+  const sandbox = sinon.createSandbox();
+  let exposureStub = sandbox.stub(ExperimentAPI, "recordExposureEvent");
+
+  sandbox.stub(ExperimentAPI._store, "get").throws();
+  sandbox.stub(ExperimentAPI._store, "getExperimentForFeature").throws();
+
+  try {
+    let metadata = ExperimentAPI.getExperimentMetaData({ slug: "foo" });
+    Assert.equal(metadata, null, "Should not throw");
+  } catch (e) {
+    Assert.ok(false, "Error should be caught in ExperimentAPI");
+  }
+
+  Assert.ok(ExperimentAPI._store.get.calledOnce, "Sanity check");
+
+  try {
+    let metadata = ExperimentAPI.getExperimentMetaData({ featureId: "foo" });
+    Assert.equal(metadata, null, "Should not throw");
+  } catch (e) {
+    Assert.ok(false, "Error should be caught in ExperimentAPI");
+  }
+
+  Assert.ok(
+    ExperimentAPI._store.getExperimentForFeature.calledOnce,
+    "Sanity check"
+  );
+
+  Assert.ok(exposureStub.notCalled, "Not called for this feature");
+
+  sandbox.restore();
+});
+
+add_task(async function test_getExperiment_feature() {
+  const sandbox = sinon.createSandbox();
+  const manager = ExperimentFakes.manager();
+  const expected = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "treatment",
+      features: [{ featureId: "cfr", value: null }],
+      feature: {
+        featureId: "unused-feature-id-for-legacy-support",
+        enabled: false,
+        value: {},
+      },
+    },
+  });
+
+  await manager.onStartup();
+
+  sandbox.stub(ExperimentAPI, "_store").get(() => ExperimentFakes.childStore());
+  let exposureStub = sandbox.stub(ExperimentAPI, "recordExposureEvent");
+
+  await manager.store.addEnrollment(expected);
+
+  // Wait to sync to child
+  await TestUtils.waitForCondition(
+    () => ExperimentAPI.getExperiment({ featureId: "cfr" }),
+    "Wait for child to sync"
+  );
+
+  Assert.equal(
+    ExperimentAPI.getExperiment({ featureId: "cfr" }).slug,
+    expected.slug,
+    "should return an experiment by featureId"
+  );
+
+  Assert.deepEqual(
+    ExperimentAPI.getExperiment({ featureId: "cfr" }).branch,
+    expected.branch,
+    "should return the right branch by featureId"
+  );
+
+  Assert.ok(exposureStub.notCalled, "Not called by default");
+
+  sandbox.restore();
+});
+
+add_task(async function test_getExperiment_safe() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI._store, "getExperimentForFeature").throws();
+
+  try {
+    Assert.equal(
+      ExperimentAPI.getExperiment({ featureId: "foo" }),
+      null,
+      "It should not fail even when it throws."
+    );
+  } catch (e) {
+    Assert.ok(false, "Error should be caught by ExperimentAPI");
+  }
+
+  sandbox.restore();
+});
+
+add_task(async function test_getExperiment_featureAccess() {
+  const sandbox = sinon.createSandbox();
+  const expected = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "treatment",
+      value: { title: "hi" },
+      features: [{ featureId: "cfr", value: { message: "content" } }],
+    },
+  });
+  const stub = sandbox
+    .stub(ExperimentAPI._store, "getExperimentForFeature")
+    .returns(expected);
+
+  let { branch } = ExperimentAPI.getExperiment({ featureId: "cfr" });
+
+  Assert.equal(branch.slug, "treatment");
+  let feature = branch.cfr;
+  Assert.ok(feature, "Should allow to access by featureId");
+  Assert.equal(feature.value.message, "content");
+
+  stub.restore();
+});
+
+add_task(async function test_getExperiment_featureAccess_backwardsCompat() {
+  const sandbox = sinon.createSandbox();
+  const expected = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "treatment",
+      feature: { featureId: "cfr", value: { message: "content" } },
+    },
+  });
+  const stub = sandbox
+    .stub(ExperimentAPI._store, "getExperimentForFeature")
+    .returns(expected);
+
+  let { branch } = ExperimentAPI.getExperiment({ featureId: "cfr" });
+
+  Assert.equal(branch.slug, "treatment");
+  let feature = branch.cfr;
+  Assert.ok(feature, "Should allow to access by featureId");
+  Assert.equal(feature.value.message, "content");
+
+  stub.restore();
+});
+
+/**
+ * #getRecipe
+ */
+add_task(async function test_getRecipe() {
+  const sandbox = sinon.createSandbox();
+  const RECIPE = ExperimentFakes.recipe("foo");
+  const collectionName = Services.prefs.getStringPref(COLLECTION_ID_PREF);
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").resolves([RECIPE]);
+
+  const recipe = await ExperimentAPI.getRecipe("foo");
+  Assert.deepEqual(
+    recipe,
+    RECIPE,
+    "should return an experiment recipe if found"
+  );
+  Assert.equal(
+    ExperimentAPI._remoteSettingsClient.collectionName,
+    collectionName,
+    "Loaded the expected collection"
+  );
+
+  sandbox.restore();
+});
+
+add_task(async function test_getRecipe_Failure() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").throws();
+
+  const recipe = await ExperimentAPI.getRecipe("foo");
+  Assert.equal(recipe, undefined, "should return undefined if RS throws");
+
+  sandbox.restore();
+});
+
+/**
+ * #getAllBranches
+ */
+add_task(async function test_getAllBranches() {
+  const sandbox = sinon.createSandbox();
+  const RECIPE = ExperimentFakes.recipe("foo");
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").resolves([RECIPE]);
+
+  const branches = await ExperimentAPI.getAllBranches("foo");
+  Assert.deepEqual(
+    branches,
+    RECIPE.branches,
+    "should return all branches if found a recipe"
+  );
+
+  sandbox.restore();
+});
+
+// API used by Messaging System
+add_task(async function test_getAllBranches_featureIdAccessor() {
+  const sandbox = sinon.createSandbox();
+  const RECIPE = ExperimentFakes.recipe("foo");
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").resolves([RECIPE]);
+
+  const branches = await ExperimentAPI.getAllBranches("foo");
+  Assert.deepEqual(
+    branches,
+    RECIPE.branches,
+    "should return all branches if found a recipe"
+  );
+  branches.forEach(branch => {
+    Assert.equal(
+      branch.testFeature.featureId,
+      "testFeature",
+      "Should use the experimentBranchAccessor proxy getter"
+    );
+  });
+
+  sandbox.restore();
+});
+
+// For schema version before 1.6.2 branch.feature was accessed
+// instead of branch.features
+add_task(async function test_getAllBranches_backwardsCompat() {
+  const sandbox = sinon.createSandbox();
+  const RECIPE = ExperimentFakes.recipe("foo");
+  delete RECIPE.branches[0].features;
+  delete RECIPE.branches[1].features;
+  let feature = {
+    featureId: "backwardsCompat",
+    value: {
+      enabled: true,
+    },
+  };
+  RECIPE.branches[0].feature = feature;
+  RECIPE.branches[1].feature = feature;
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").resolves([RECIPE]);
+
+  const branches = await ExperimentAPI.getAllBranches("foo");
+  Assert.deepEqual(
+    branches,
+    RECIPE.branches,
+    "should return all branches if found a recipe"
+  );
+  branches.forEach(branch => {
+    Assert.equal(
+      branch.backwardsCompat.featureId,
+      "backwardsCompat",
+      "Should use the experimentBranchAccessor proxy getter"
+    );
+  });
+
+  sandbox.restore();
+});
+
+add_task(async function test_getAllBranches_Failure() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI._remoteSettingsClient, "get").throws();
+
+  const branches = await ExperimentAPI.getAllBranches("foo");
+  Assert.equal(branches, undefined, "should return undefined if RS throws");
+
+  sandbox.restore();
+});
+
+/**
+ * #on
+ * #off
+ */
+add_task(async function test_addEnrollment_eventEmit_add() {
+  const sandbox = sinon.createSandbox();
+  const slugStub = sandbox.stub();
+  const featureStub = sandbox.stub();
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "purple", value: null }],
+    },
+  });
+  const store = ExperimentFakes.store();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+
+  await store.init();
+  await ExperimentAPI.ready();
+
+  ExperimentAPI.on("update", { slug: "foo" }, slugStub);
+  ExperimentAPI.on("update", { featureId: "purple" }, featureStub);
+
+  await store.addEnrollment(experiment);
+
+  Assert.equal(
+    slugStub.callCount,
+    1,
+    "should call 'update' callback for slug when experiment is added"
+  );
+  Assert.equal(slugStub.firstCall.args[1].slug, experiment.slug);
+  Assert.equal(
+    featureStub.callCount,
+    1,
+    "should call 'update' callback for featureId when an experiment is added"
+  );
+  Assert.equal(featureStub.firstCall.args[1].slug, experiment.slug);
+});
+
+add_task(async function test_updateExperiment_eventEmit_add_and_update() {
+  const sandbox = sinon.createSandbox();
+  const slugStub = sandbox.stub();
+  const featureStub = sandbox.stub();
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "purple", value: null }],
+    },
+  });
+  const store = ExperimentFakes.store();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+
+  await store.init();
+  await ExperimentAPI.ready();
+
+  await store.addEnrollment(experiment);
+
+  ExperimentAPI.on("update", { slug: "foo" }, slugStub);
+  ExperimentAPI.on("update", { featureId: "purple" }, featureStub);
+
+  store.updateExperiment(experiment.slug, experiment);
+
+  await TestUtils.waitForCondition(
+    () => slugStub.callCount == 2,
+    "Wait for `on` method to notify callback about the `add` event."
+  );
+  // Called twice, once when attaching the event listener (because there is an
+  // existing experiment with that name) and 2nd time for the update event
+  Assert.equal(slugStub.firstCall.args[1].slug, experiment.slug);
+  Assert.equal(featureStub.callCount, 2, "Called twice for feature");
+  Assert.equal(featureStub.firstCall.args[1].slug, experiment.slug);
+});
+
+add_task(async function test_updateExperiment_eventEmit_off() {
+  const sandbox = sinon.createSandbox();
+  const slugStub = sandbox.stub();
+  const featureStub = sandbox.stub();
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "purple", value: null }],
+    },
+  });
+  const store = ExperimentFakes.store();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+
+  await store.init();
+  await ExperimentAPI.ready();
+
+  ExperimentAPI.on("update", { slug: "foo" }, slugStub);
+  ExperimentAPI.on("update", { featureId: "purple" }, featureStub);
+
+  await store.addEnrollment(experiment);
+
+  ExperimentAPI.off("update:foo", slugStub);
+  ExperimentAPI.off("update:purple", featureStub);
+
+  store.updateExperiment(experiment.slug, experiment);
+
+  Assert.equal(slugStub.callCount, 1, "Called only once before `off`");
+  Assert.equal(featureStub.callCount, 1, "Called only once before `off`");
+});
+
+add_task(async function test_getActiveBranch() {
+  const sandbox = sinon.createSandbox();
+  const store = ExperimentFakes.store();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "green", value: null }],
+    },
+  });
+
+  await store.init();
+  await store.addEnrollment(experiment);
+
+  Assert.deepEqual(
+    ExperimentAPI.getActiveBranch({ featureId: "green" }),
+    experiment.branch,
+    "Should return feature of active experiment"
+  );
+
+  sandbox.restore();
+});
+
+add_task(async function test_getActiveBranch_safe() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI._store, "getAllActive").throws();
+
+  try {
+    Assert.equal(
+      ExperimentAPI.getActiveBranch({ featureId: "green" }),
+      null,
+      "Should not throw"
+    );
+  } catch (e) {
+    Assert.ok(false, "Should catch error in ExperimentAPI");
+  }
+
+  sandbox.restore();
+});
+
+add_task(async function test_getActiveBranch_storeFailure() {
+  const store = ExperimentFakes.store();
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "green" }],
+    },
+  });
+
+  await store.init();
+  await store.addEnrollment(experiment);
+  // Adding stub later because `addEnrollment` emits update events
+  const stub = sandbox.stub(store, "emit");
+  // Call getActiveBranch to trigger an activation event
+  sandbox.stub(store, "getAllActive").throws();
+  try {
+    ExperimentAPI.getActiveBranch({ featureId: "green" });
+  } catch (e) {
+    /* This is expected */
+  }
+
+  Assert.equal(stub.callCount, 0, "Not called if store somehow fails");
+  sandbox.restore();
+});
+
+add_task(async function test_getActiveBranch_noActivationEvent() {
+  const store = ExperimentFakes.store();
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(ExperimentAPI, "_store").get(() => store);
+  const experiment = ExperimentFakes.experiment("foo", {
+    branch: {
+      slug: "variant",
+      features: [{ featureId: "green" }],
+    },
+  });
+
+  await store.init();
+  await store.addEnrollment(experiment);
+  // Adding stub later because `addEnrollment` emits update events
+  const stub = sandbox.stub(store, "emit");
+  // Call getActiveBranch to trigger an activation event
+  ExperimentAPI.getActiveBranch({ featureId: "green" });
+
+  Assert.equal(stub.callCount, 0, "Not called: sendExposureEvent is false");
+  sandbox.restore();
+});