Merge pull request #1856 from Financial-Times/DATA-9749

feat: add timestamp to session generations in o-tracking

libraries/o-tracking/src/javascript/core.js

@@ -55,6 +55,7 @@ function track(config, callback = function(){ /* empty */}) {
 		device: {
 			spoor_session: currentSession.id,
 			spoor_session_is_new: currentSession.isNew,
+			spoor_session_timestamp: currentSession.timestamp,
 			spoor_id: userID(),
 		},
 	};

libraries/o-tracking/src/javascript/core/session.js

@@ -1,13 +1,15 @@
-import {is, merge, isUndefined, guid} from '../utils.js';
+import {is, merge, isUndefined, guid, namedLog} from '../utils.js';
 import {Store} from './store.js';
 
 /**
  * @typedef {object} Session
  * @property {string} id - The id of the session
  * @property {boolean} isNew - Whether it is a brand new session
+ * @property {number} timestamp - The timestamp of the session generation
  */
 
 let store;
+const logger = namedLog('Core.Session')
 const defaultSessionConfig = {
 	storage: 'best',
 	name: 'session',
@@ -20,14 +22,20 @@ const defaultSessionConfig = {
  * @param {string} session - The session to be stored.
  * @returns {void}
  */
-function setSession(session) {
+function setSession(session, timestamp) {
 	const d = new Date();
 	d.setTime(d.getTime() + store.config.expires);
 
-	store.write({
+	const sessionData = {
 		value: session,
-		expiry: d.valueOf()
-	});
+		expiry: d.valueOf(),
+	}
+	if(timestamp) {
+		sessionData.timestamp = timestamp;
+	}
+	logger('Setting session', sessionData)
+
+	store.write(sessionData);
 }
 
 /**
@@ -39,32 +47,48 @@ function getSession() {
 	const s = store.read();
 	let session;
 	let isNew = false;
+	let sessionTimestamp;
 
 	if (s) {
-		const d = new Date().valueOf();
+		logger("Found session", s)
+		const currentDate = new Date();
+		const d = currentDate.valueOf();
+		const timestamp = currentDate.getTime();
 		const exp = parseInt(s.expiry, 10);
 
 		// If current session is active.
 		if (exp >= d) {
 			session = s.value;
+			sessionTimestamp = s.timestamp;
+
+			// session is active but no generated timestamp
+			if(!sessionTimestamp) {
+				logger("Session is valid but no timestamp, generating timestamp.")
+				sessionTimestamp = timestamp;
+			}
 		} else {
-			// session has expired, generate a new one
+			// session has expired, generate a new one along with a new timestamp
+			logger("Session has expired, generating new one")
+			sessionTimestamp = timestamp;
 			session = guid();
 			isNew = true;
 		}
 	}
 
 	// No active session, gen a new one.
 	if (!session) {
+		logger("No session found, generating new one")
 		session = guid();
+		sessionTimestamp = new Date().getTime();
 		isNew = true;
 	}
 
 	// Refreshes the cookie...
-	setSession(session);
+	setSession(session, sessionTimestamp);
 
 	return {
 		id: session,
+		timestamp: sessionTimestamp,
 		isNew: isNew
 	};
 }

libraries/o-tracking/src/javascript/tracking.js

@@ -17,7 +17,7 @@ const initPage = page.init;
  *
  * @type {string}
  */
-const version = '4.5.4';
+const version = '4.5.5';
 
 /**
  * The source of this event.

libraries/o-tracking/src/javascript/utils.js

@@ -27,6 +27,26 @@ function log(...args) {
 	}
 }
 
+/**
+ * Creates a logging function that logs messages to the console with a specified namespace.
+ *
+ * @function namedLog
+ * @param {string} namespace - The namespace to be prefixed to each log message.
+ * @returns {function} A function that logs messages to the console with the given namespace if the configuration allows.
+ *
+ * @example
+ * const log = namedLog('MyNamespace');
+ * log('This is a message'); 
+ * // Output: [MyNamespace]: This is a message
+ */
+function namedLog(namespace) {
+	return function(...args) {
+		if(get('config').test && window.console) {
+			window.console.log(`%c[${namespace}]:`, 'color: teal', ...args)
+		}
+	}
+}
+
 /**
  * Tests if variable is a certain type. Defaults to check for undefined if no type specified.
  *
@@ -389,6 +409,7 @@ function isDeepEqual(a, b) {
 
 export {
 	log,
+	namedLog,
 	is,
 	is as isUndefined,
 	merge,

libraries/o-tracking/test/core.test.js

@@ -78,9 +78,10 @@ describe('Core', function () {
 			proclaim.equal(sent_data.user.user_id, "userID");
 
 			// Device
-			proclaim.deepEqual(Object.keys(sent_data.device), ["spoor_session","spoor_session_is_new","spoor_id"]);
+			proclaim.deepEqual(Object.keys(sent_data.device), ["spoor_session","spoor_session_is_new","spoor_session_timestamp", "spoor_id"]);
 			proclaim.equal(sent_data.device.spoor_session, session().id);
 			proclaim.equal(sent_data.device.spoor_session_is_new, session().isNew);
+			proclaim.equal(sent_data.device.spoor_session_timestamp, session().timestamp);
 
 		});
 

libraries/o-tracking/test/core/session.test.js

@@ -35,6 +35,7 @@ describe('Core.Session', function () {
 			const newSession = getSession();
 			proclaim.equal(newSession.id, session.id);
 			proclaim.equal(newSession.isNew, false);
+			proclaim.equal(newSession.timestamp, session.timestamp)
 		});
 	});
 
@@ -59,6 +60,20 @@ describe('Core.Session', function () {
 				proclaim.isTrue(newSession.isNew);
 				done();
 			}, 2)
+		});
+
+		it('should generate timestamp for session', () => {
+			const currentTimestamp = new Date().getTime();
+			proclaim.equal(currentTimestamp, getSession().timestamp)
+		})
+
+		it('should generate a new timestamp if session has expired', (done) => {
+			const prevSession = initSession({expires: 1});
+			setTimeout(function() {
+				const newSession = getSession();
+				proclaim.notEqual(prevSession.timestamp, newSession.timestamp);
+				done()
+			}, 2)
 		})
 	})
 });