1 files changed, 120 insertions, 0 deletions
diff --git a/browser/components/newtab/test/unit/content-src/lib/detect-user-session-start.test.js b/browser/components/newtab/test/unit/content-src/lib/detect-user-session-start.test.js
new file mode 100644
index 0000000000..5a7fad7cc0
--- /dev/null
+++ b/browser/components/newtab/test/unit/content-src/lib/detect-user-session-start.test.js
@@ -0,0 +1,120 @@
+import {
+  actionCreators as ac,
+  actionTypes as at,
+} from "common/Actions.sys.mjs";
+import { DetectUserSessionStart } from "content-src/lib/detect-user-session-start";
+
+describe("detectUserSessionStart", () => {
+  let store;
+  class PerfService {
+    getMostRecentAbsMarkStartByName() {
+      return 1234;
+    }
+    mark() {}
+  }
+
+  beforeEach(() => {
+    store = { dispatch: () => {} };
+  });
+  describe("#sendEventOrAddListener", () => {
+    it("should call ._sendEvent immediately if the document is visible", () => {
+      const mockDocument = { visibilityState: "visible" };
+      const instance = new DetectUserSessionStart(store, {
+        document: mockDocument,
+      });
+      sinon.stub(instance, "_sendEvent");
+
+      instance.sendEventOrAddListener();
+
+      assert.calledOnce(instance._sendEvent);
+    });
+    it("should add an event listener on visibility changes the document is not visible", () => {
+      const mockDocument = {
+        visibilityState: "hidden",
+        addEventListener: sinon.spy(),
+      };
+      const instance = new DetectUserSessionStart(store, {
+        document: mockDocument,
+      });
+      sinon.stub(instance, "_sendEvent");
+
+      instance.sendEventOrAddListener();
+
+      assert.notCalled(instance._sendEvent);
+      assert.calledWith(
+        mockDocument.addEventListener,
+        "visibilitychange",
+        instance._onVisibilityChange
+      );
+    });
+  });
+  describe("#_sendEvent", () => {
+    it("should dispatch an action with the SAVE_SESSION_PERF_DATA", () => {
+      const dispatch = sinon.spy(store, "dispatch");
+      const instance = new DetectUserSessionStart(store);
+
+      instance._sendEvent();
+
+      assert.calledWith(
+        dispatch,
+        ac.AlsoToMain({
+          type: at.SAVE_SESSION_PERF_DATA,
+          data: { visibility_event_rcvd_ts: sinon.match.number },
+        })
+      );
+    });
+
+    it("shouldn't send a message if getMostRecentAbsMarkStartByName throws", () => {
+      let perfService = new PerfService();
+      sinon.stub(perfService, "getMostRecentAbsMarkStartByName").throws();
+      const dispatch = sinon.spy(store, "dispatch");
+      const instance = new DetectUserSessionStart(store, { perfService });
+
+      instance._sendEvent();
+
+      assert.notCalled(dispatch);
+    });
+
+    it('should call perfService.mark("visibility_event_rcvd_ts")', () => {
+      let perfService = new PerfService();
+      sinon.stub(perfService, "mark");
+      const instance = new DetectUserSessionStart(store, { perfService });
+
+      instance._sendEvent();
+
+      assert.calledWith(perfService.mark, "visibility_event_rcvd_ts");
+    });
+  });
+
+  describe("_onVisibilityChange", () => {
+    it("should not send an event if visiblity is not visible", () => {
+      const instance = new DetectUserSessionStart(store, {
+        document: { visibilityState: "hidden" },
+      });
+      sinon.stub(instance, "_sendEvent");
+
+      instance._onVisibilityChange();
+
+      assert.notCalled(instance._sendEvent);
+    });
+    it("should send an event and remove the event listener if visibility is visible", () => {
+      const mockDocument = {
+        visibilityState: "visible",
+        removeEventListener: sinon.spy(),
+      };
+      const instance = new DetectUserSessionStart(store, {
+        document: mockDocument,
+      });
+      sinon.stub(instance, "_sendEvent");
+
+      instance._onVisibilityChange();
+
+      assert.calledOnce(instance._sendEvent);
+      assert.calledWith(
+        mockDocument.removeEventListener,
+        "visibilitychange",
+        instance._onVisibilityChange
+      );
+    });
+  });
+});