From 7b83ba7315df472273c0403c41a8c339723e6c8f Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 28 Feb 2024 15:37:34 -0500
Subject: [PATCH 1/9] Refactor to use modified dt for _lastPing

---
 pkgs/unified_analytics/lib/src/analytics.dart |  5 ++
 pkgs/unified_analytics/lib/src/constants.dart |  2 +-
 .../lib/src/initializer.dart                  |  7 +--
 pkgs/unified_analytics/lib/src/session.dart   | 51 ++++++-------------
 4 files changed, 23 insertions(+), 42 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/analytics.dart b/pkgs/unified_analytics/lib/src/analytics.dart
index 0c3a98721..31f2c5de8 100644
--- a/pkgs/unified_analytics/lib/src/analytics.dart
+++ b/pkgs/unified_analytics/lib/src/analytics.dart
@@ -430,6 +430,11 @@ class AnalyticsImpl implements Analytics {
       homeDirectory: homeDirectory,
       fs: fs,
       errorHandler: _errorHandler,
+      sessionFile: fs.file(p.join(
+        homeDirectory.path,
+        kDartToolDirectoryName,
+        kSessionFileName,
+      )),
     );
     userProperty = UserProperty(
       session: _sessionHandler,
diff --git a/pkgs/unified_analytics/lib/src/constants.dart b/pkgs/unified_analytics/lib/src/constants.dart
index 4dfca3e2e..8c3193a67 100644
--- a/pkgs/unified_analytics/lib/src/constants.dart
+++ b/pkgs/unified_analytics/lib/src/constants.dart
@@ -88,7 +88,7 @@ const String kPackageVersion = '5.8.5';
 const int kSessionDurationMinutes = 30;
 
 /// Name for the json file where the session details will be stored.
-const String kSessionFileName = 'dart-flutter-telemetry-session.json';
+const String kSessionFileName = 'dart-flutter-telemetry.session';
 
 /// The message that should be shown to the user.
 const String kToolsMessage = '''
diff --git a/pkgs/unified_analytics/lib/src/initializer.dart b/pkgs/unified_analytics/lib/src/initializer.dart
index 22898a92d..2e7bbb0f3 100644
--- a/pkgs/unified_analytics/lib/src/initializer.dart
+++ b/pkgs/unified_analytics/lib/src/initializer.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:convert';
-
 import 'package:clock/clock.dart';
 import 'package:file/file.dart';
 import 'package:path/path.dart' as p;
@@ -82,10 +80,7 @@ class Initializer {
   static void createSessionFile({required File sessionFile}) {
     final now = clock.now();
     sessionFile.createSync(recursive: true);
-    sessionFile.writeAsStringSync(jsonEncode(<String, int>{
-      'session_id': now.millisecondsSinceEpoch,
-      'last_ping': now.millisecondsSinceEpoch,
-    }));
+    sessionFile.writeAsStringSync('${now.millisecondsSinceEpoch}');
   }
 
   /// This will check that there is a client ID populated in
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index 80305ee18..f9cbacdf3 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -2,11 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:convert';
-
 import 'package:clock/clock.dart';
 import 'package:file/file.dart';
-import 'package:path/path.dart' as p;
 
 import 'constants.dart';
 import 'error_handler.dart';
@@ -19,19 +16,18 @@ class Session {
   final File sessionFile;
   final ErrorHandler _errorHandler;
 
-  late int _sessionId;
-  late int _lastPing;
+  int _sessionId;
 
   Session({
     required this.homeDirectory,
     required this.fs,
     required ErrorHandler errorHandler,
-  })  : sessionFile = fs.file(p.join(
-            homeDirectory.path, kDartToolDirectoryName, kSessionFileName)),
+    required this.sessionFile,
+  })  : _sessionId = int.parse(sessionFile.readAsStringSync()),
         _errorHandler = errorHandler;
 
   /// This will use the data parsed from the
-  /// session json file in the dart-tool directory
+  /// session file in the dart-tool directory
   /// to get the session id if the last ping was within
   /// [kSessionDurationMinutes].
   ///
@@ -46,24 +42,22 @@ class Session {
 
     // Convert the epoch time from the last ping into datetime and check if we
     // are within the kSessionDurationMinutes.
-    final lastPingDateTime = DateTime.fromMillisecondsSinceEpoch(_lastPing);
+    final lastPingDateTime = DateTime.fromMillisecondsSinceEpoch(
+        sessionFile.lastModifiedSync().millisecondsSinceEpoch);
     if (now.difference(lastPingDateTime).inMinutes > kSessionDurationMinutes) {
-      // In this case, we will need to change both the session id
-      // and the last ping value
+      // Update the session file with the latest session id
       _sessionId = now.millisecondsSinceEpoch;
+      sessionFile.writeAsStringSync('$_sessionId');
     }
 
-    // Update the last ping to reflect session activity continuing
-    _lastPing = now.millisecondsSinceEpoch;
-
-    // Rewrite the session object back to the file to persist
-    // for future events
-    sessionFile.writeAsStringSync(toJson());
+    // Update the last modified timestamp with the current timestamp so that
+    // we can use it for the next _lastPing calculation
+    sessionFile.setLastModifiedSync(now);
 
     return _sessionId;
   }
 
-  /// Preps the [Session] class with the data found in the session json file.
+  /// Preps the [Session] class with the data found in the session file.
   ///
   /// We must check if telemetry is enabled to refresh the session data
   /// because the refresh method will write to the session file and for
@@ -73,15 +67,9 @@ class Session {
     if (telemetryEnabled) _refreshSessionData();
   }
 
-  /// Return a json formatted representation of the class.
-  String toJson() => jsonEncode(<String, int>{
-        'session_id': _sessionId,
-        'last_ping': _lastPing,
-      });
-
   /// This will go to the session file within the dart-tool
-  /// directory and fetch the latest data from the json to update
-  /// the class's variables. If the json file is malformed, a new
+  /// directory and fetch the latest data from the session file to update
+  /// the class's variables. If the session file is malformed, a new
   /// session file will be recreated.
   ///
   /// This allows the session data in this class to always be up
@@ -89,13 +77,8 @@ class Session {
   /// making updates to the session file.
   void _refreshSessionData() {
     /// Using a nested function here to reduce verbosity
-    void parseContents() {
-      final sessionFileContents = sessionFile.readAsStringSync();
-      final sessionObj =
-          jsonDecode(sessionFileContents) as Map<String, Object?>;
-      _sessionId = sessionObj['session_id'] as int;
-      _lastPing = sessionObj['last_ping'] as int;
-    }
+    void parseContents() =>
+        _sessionId = int.parse(sessionFile.readAsStringSync());
 
     try {
       parseContents();
@@ -111,7 +94,6 @@ class Session {
       // Fallback to setting the session id as the current time
       final now = clock.now();
       _sessionId = now.millisecondsSinceEpoch;
-      _lastPing = now.millisecondsSinceEpoch;
     } on FileSystemException catch (err) {
       Initializer.createSessionFile(sessionFile: sessionFile);
 
@@ -124,7 +106,6 @@ class Session {
       // Fallback to setting the session id as the current time
       final now = clock.now();
       _sessionId = now.millisecondsSinceEpoch;
-      _lastPing = now.millisecondsSinceEpoch;
     }
   }
 }

From 09e168093742b6c1c6e44399cdd41f0f0b9102f9 Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 28 Feb 2024 16:03:48 -0500
Subject: [PATCH 2/9] Fix tests + misc dartdoc fixes

---
 .../lib/src/initializer.dart                  |  6 +--
 pkgs/unified_analytics/lib/src/session.dart   |  2 +-
 .../test/unified_analytics_test.dart          | 46 ++++++-------------
 3 files changed, 17 insertions(+), 37 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/initializer.dart b/pkgs/unified_analytics/lib/src/initializer.dart
index 2e7bbb0f3..64d3a0f2c 100644
--- a/pkgs/unified_analytics/lib/src/initializer.dart
+++ b/pkgs/unified_analytics/lib/src/initializer.dart
@@ -73,10 +73,8 @@ class Initializer {
     logFile.createSync(recursive: true);
   }
 
-  /// Creates the session json file which will contain
-  /// the current session id along with the timestamp for
-  /// the last ping which will be used to increment the session
-  /// if current timestamp is greater than the session window.
+  /// Creates the session file which will contain
+  /// the current session id which is the current timestamp.
   static void createSessionFile({required File sessionFile}) {
     final now = clock.now();
     sessionFile.createSync(recursive: true);
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index f9cbacdf3..103f62706 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -23,7 +23,7 @@ class Session {
     required this.fs,
     required ErrorHandler errorHandler,
     required this.sessionFile,
-  })  : _sessionId = int.parse(sessionFile.readAsStringSync()),
+  })  : _sessionId = DateTime.now().millisecondsSinceEpoch,
         _errorHandler = errorHandler;
 
   /// This will use the data parsed from the
diff --git a/pkgs/unified_analytics/test/unified_analytics_test.dart b/pkgs/unified_analytics/test/unified_analytics_test.dart
index 39046f74d..c7ae7a387 100644
--- a/pkgs/unified_analytics/test/unified_analytics_test.dart
+++ b/pkgs/unified_analytics/test/unified_analytics_test.dart
@@ -132,7 +132,7 @@ void main() {
 
   test('Resetting session file when data is malformed', () {
     // Purposefully write content to the session file that
-    // can't be decoded as json
+    // can't be decoded as an integer
     sessionFile.writeAsStringSync('contents');
 
     // Define the initial time to start
@@ -143,8 +143,7 @@ void main() {
       final timestamp = clock.now().millisecondsSinceEpoch.toString();
       expect(sessionFile.readAsStringSync(), 'contents');
       analytics.userProperty.preparePayload();
-      expect(sessionFile.readAsStringSync(),
-          '{"session_id":$timestamp,"last_ping":$timestamp}');
+      expect(sessionFile.readAsStringSync(), timestamp);
 
       // Attempting to fetch the session id when malformed should also
       // send an error event while parsing
@@ -158,9 +157,9 @@ void main() {
 
   test('Handles malformed session file on startup', () {
     // Ensure that we are able to send an error message on startup if
-    // we encounter an error while parsing the contents of the json file
+    // we encounter an error while parsing the contents of the session file
     // for session data
-    sessionFile.writeAsStringSync('contents');
+    sessionFile.writeAsStringSync('not a valid session id');
 
     analytics = Analytics.test(
       tool: initialTool,
@@ -185,7 +184,7 @@ void main() {
     expect(errorEvent!.eventData['workflow'], 'Session._refreshSessionData');
     expect(errorEvent.eventData['error'], 'FormatException');
     expect(errorEvent.eventData['description'],
-        'message: Unexpected character\nsource: contents');
+        'message: Invalid radix-10 number\nsource: not a valid session id');
   });
 
   test('Resetting session file when file is removed', () {
@@ -200,8 +199,7 @@ void main() {
       final timestamp = clock.now().millisecondsSinceEpoch.toString();
       expect(sessionFile.existsSync(), false);
       analytics.userProperty.preparePayload();
-      expect(sessionFile.readAsStringSync(),
-          '{"session_id":$timestamp,"last_ping":$timestamp}');
+      expect(sessionFile.readAsStringSync(), timestamp);
 
       // Attempting to fetch the session id when malformed should also
       // send an error event while parsing
@@ -701,14 +699,10 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
       );
       secondAnalytics.clientShowedMessage();
 
-      // Read the contents of the session file
-      final sessionFileContents = sessionFile.readAsStringSync();
-      final sessionObj =
-          jsonDecode(sessionFileContents) as Map<String, Object?>;
-
       expect(secondAnalytics.userPropertyMap['session_id']?['value'],
           start.millisecondsSinceEpoch);
-      expect(sessionObj['last_ping'], start.millisecondsSinceEpoch);
+      expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
+          start.millisecondsSinceEpoch);
     });
 
     // Add time to the start time that is less than the duration
@@ -739,16 +733,12 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
       // no events will be sent
       thirdAnalytics.send(testEvent);
 
-      // Read the contents of the session file
-      final sessionFileContents = sessionFile.readAsStringSync();
-      final sessionObj =
-          jsonDecode(sessionFileContents) as Map<String, Object?>;
-
       expect(thirdAnalytics.userPropertyMap['session_id']?['value'],
           start.millisecondsSinceEpoch,
           reason: 'The session id should not have changed since it was made '
               'within the duration');
-      expect(sessionObj['last_ping'], end.millisecondsSinceEpoch,
+      expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
+          end.millisecondsSinceEpoch,
           reason: 'The last_ping value should have been updated');
     });
   });
@@ -782,14 +772,10 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
       );
       secondAnalytics.clientShowedMessage();
 
-      // Read the contents of the session file
-      final sessionFileContents = sessionFile.readAsStringSync();
-      final sessionObj =
-          jsonDecode(sessionFileContents) as Map<String, Object?>;
-
       expect(secondAnalytics.userPropertyMap['session_id']?['value'],
           start.millisecondsSinceEpoch);
-      expect(sessionObj['last_ping'], start.millisecondsSinceEpoch);
+      expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
+          start.millisecondsSinceEpoch);
 
       secondAnalytics.send(testEvent);
     });
@@ -822,16 +808,12 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
       // no events will be sent
       thirdAnalytics.send(testEvent);
 
-      // Read the contents of the session file
-      final sessionFileContents = sessionFile.readAsStringSync();
-      final sessionObj =
-          jsonDecode(sessionFileContents) as Map<String, Object?>;
-
       expect(thirdAnalytics.userPropertyMap['session_id']?['value'],
           end.millisecondsSinceEpoch,
           reason: 'The session id should have changed since it was made '
               'outside the duration');
-      expect(sessionObj['last_ping'], end.millisecondsSinceEpoch,
+      expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
+          end.millisecondsSinceEpoch,
           reason: 'The last_ping value should have been updated');
     });
   });

From 09caa2a98b4dff6024a3bb872d219f291808a0d8 Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 28 Feb 2024 16:07:30 -0500
Subject: [PATCH 3/9] Bump version

---
 pkgs/unified_analytics/CHANGELOG.md           | 4 ++++
 pkgs/unified_analytics/lib/src/constants.dart | 2 +-
 pkgs/unified_analytics/pubspec.yaml           | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/pkgs/unified_analytics/CHANGELOG.md b/pkgs/unified_analytics/CHANGELOG.md
index a35dcd692..86fb6ac25 100644
--- a/pkgs/unified_analytics/CHANGELOG.md
+++ b/pkgs/unified_analytics/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.8.6
+
+- Refactored session handler class to use the last modified timestamp as the last ping value
+
 ## 5.8.5
 
 - Fix late initialization error for `Analytics.userProperty` [bug](https://github.com/dart-lang/tools/issues/238)
diff --git a/pkgs/unified_analytics/lib/src/constants.dart b/pkgs/unified_analytics/lib/src/constants.dart
index 8c3193a67..9f85b90a1 100644
--- a/pkgs/unified_analytics/lib/src/constants.dart
+++ b/pkgs/unified_analytics/lib/src/constants.dart
@@ -82,7 +82,7 @@ const int kLogFileLength = 2500;
 const String kLogFileName = 'dart-flutter-telemetry.log';
 
 /// The current version of the package, should be in line with pubspec version.
-const String kPackageVersion = '5.8.5';
+const String kPackageVersion = '5.8.6';
 
 /// The minimum length for a session.
 const int kSessionDurationMinutes = 30;
diff --git a/pkgs/unified_analytics/pubspec.yaml b/pkgs/unified_analytics/pubspec.yaml
index 8cd92f041..121c92170 100644
--- a/pkgs/unified_analytics/pubspec.yaml
+++ b/pkgs/unified_analytics/pubspec.yaml
@@ -4,7 +4,7 @@ description: >-
   to Google Analytics.
 # When updating this, keep the version consistent with the changelog and the
 # value in lib/src/constants.dart.
-version: 5.8.5
+version: 5.8.6
 repository: https://github.com/dart-lang/tools/tree/main/pkgs/unified_analytics
 
 environment:

From 3f7ee72d76a97e22ee6ce0656b13d5d1ac2b75ec Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 28 Feb 2024 16:15:49 -0500
Subject: [PATCH 4/9] Create `sessionFile` in constructor

---
 pkgs/unified_analytics/lib/src/analytics.dart | 5 -----
 pkgs/unified_analytics/lib/src/session.dart   | 6 ++++--
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/analytics.dart b/pkgs/unified_analytics/lib/src/analytics.dart
index 31f2c5de8..0c3a98721 100644
--- a/pkgs/unified_analytics/lib/src/analytics.dart
+++ b/pkgs/unified_analytics/lib/src/analytics.dart
@@ -430,11 +430,6 @@ class AnalyticsImpl implements Analytics {
       homeDirectory: homeDirectory,
       fs: fs,
       errorHandler: _errorHandler,
-      sessionFile: fs.file(p.join(
-        homeDirectory.path,
-        kDartToolDirectoryName,
-        kSessionFileName,
-      )),
     );
     userProperty = UserProperty(
       session: _sessionHandler,
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index 103f62706..cf09a00d8 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -4,6 +4,7 @@
 
 import 'package:clock/clock.dart';
 import 'package:file/file.dart';
+import 'package:path/path.dart' as p;
 
 import 'constants.dart';
 import 'error_handler.dart';
@@ -22,8 +23,9 @@ class Session {
     required this.homeDirectory,
     required this.fs,
     required ErrorHandler errorHandler,
-    required this.sessionFile,
-  })  : _sessionId = DateTime.now().millisecondsSinceEpoch,
+  })  : sessionFile = fs.file(p.join(
+            homeDirectory.path, kDartToolDirectoryName, kSessionFileName)),
+        _sessionId = DateTime.now().millisecondsSinceEpoch,
         _errorHandler = errorHandler;
 
   /// This will use the data parsed from the

From 00568cbea6c4caa81d18fcc55ac1a8db37bf5b8b Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 28 Feb 2024 16:30:07 -0500
Subject: [PATCH 5/9] Simplify `lastPingDateTime`

---
 pkgs/unified_analytics/lib/src/session.dart | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index cf09a00d8..b5c16d155 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -44,8 +44,7 @@ class Session {
 
     // Convert the epoch time from the last ping into datetime and check if we
     // are within the kSessionDurationMinutes.
-    final lastPingDateTime = DateTime.fromMillisecondsSinceEpoch(
-        sessionFile.lastModifiedSync().millisecondsSinceEpoch);
+    final lastPingDateTime = sessionFile.lastModifiedSync();
     if (now.difference(lastPingDateTime).inMinutes > kSessionDurationMinutes) {
       // Update the session file with the latest session id
       _sessionId = now.millisecondsSinceEpoch;

From 66a91987426a940e1aba4cab8b88999f679dbebe Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Thu, 29 Feb 2024 10:46:35 -0500
Subject: [PATCH 6/9] Revert filename + pass session id to initializer

---
 pkgs/unified_analytics/lib/src/constants.dart |  2 +-
 .../lib/src/initializer.dart                  | 13 +++++++--
 pkgs/unified_analytics/lib/src/session.dart   | 28 ++++++++++++++-----
 .../test/unified_analytics_test.dart          |  6 ++--
 4 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/constants.dart b/pkgs/unified_analytics/lib/src/constants.dart
index 9f85b90a1..2ab6bfe2e 100644
--- a/pkgs/unified_analytics/lib/src/constants.dart
+++ b/pkgs/unified_analytics/lib/src/constants.dart
@@ -88,7 +88,7 @@ const String kPackageVersion = '5.8.6';
 const int kSessionDurationMinutes = 30;
 
 /// Name for the json file where the session details will be stored.
-const String kSessionFileName = 'dart-flutter-telemetry.session';
+const String kSessionFileName = 'dart-flutter-telemetry-session.json';
 
 /// The message that should be shown to the user.
 const String kToolsMessage = '''
diff --git a/pkgs/unified_analytics/lib/src/initializer.dart b/pkgs/unified_analytics/lib/src/initializer.dart
index 64d3a0f2c..4f84ef1d5 100644
--- a/pkgs/unified_analytics/lib/src/initializer.dart
+++ b/pkgs/unified_analytics/lib/src/initializer.dart
@@ -75,10 +75,17 @@ class Initializer {
 
   /// Creates the session file which will contain
   /// the current session id which is the current timestamp.
-  static void createSessionFile({required File sessionFile}) {
-    final now = clock.now();
+  ///
+  /// [sessionIdOverride] can be provided as an override, otherwise it
+  /// will use the current timestamp from [Clock.now].
+  static void createSessionFile({
+    required File sessionFile,
+    DateTime? sessionIdOverride,
+  }) {
+    final now = sessionIdOverride ?? clock.now();
     sessionFile.createSync(recursive: true);
-    sessionFile.writeAsStringSync('${now.millisecondsSinceEpoch}');
+    sessionFile
+        .writeAsStringSync('{"session_id": ${now.millisecondsSinceEpoch}}');
   }
 
   /// This will check that there is a client ID populated in
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index b5c16d155..a1d57d841 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'dart:convert';
+
 import 'package:clock/clock.dart';
 import 'package:file/file.dart';
 import 'package:path/path.dart' as p;
@@ -48,7 +50,7 @@ class Session {
     if (now.difference(lastPingDateTime).inMinutes > kSessionDurationMinutes) {
       // Update the session file with the latest session id
       _sessionId = now.millisecondsSinceEpoch;
-      sessionFile.writeAsStringSync('$_sessionId');
+      sessionFile.writeAsStringSync('{"session_id": $_sessionId}');
     }
 
     // Update the last modified timestamp with the current timestamp so that
@@ -78,13 +80,23 @@ class Session {
   /// making updates to the session file.
   void _refreshSessionData() {
     /// Using a nested function here to reduce verbosity
-    void parseContents() =>
-        _sessionId = int.parse(sessionFile.readAsStringSync());
+    void parseContents() {
+      final sessionFileContents = sessionFile.readAsStringSync();
+      final sessionObj =
+          jsonDecode(sessionFileContents) as Map<String, Object?>;
+      _sessionId = sessionObj['session_id'] as int;
+    }
 
     try {
+      // Failing to parse the contents will result in the current timestamp
+      // being used as the session id and will get used to recreate the file
       parseContents();
     } on FormatException catch (err) {
-      Initializer.createSessionFile(sessionFile: sessionFile);
+      final now = clock.now();
+      Initializer.createSessionFile(
+        sessionFile: sessionFile,
+        sessionIdOverride: now,
+      );
 
       _errorHandler.log(Event.analyticsException(
         workflow: 'Session._refreshSessionData',
@@ -93,10 +105,13 @@ class Session {
       ));
 
       // Fallback to setting the session id as the current time
-      final now = clock.now();
       _sessionId = now.millisecondsSinceEpoch;
     } on FileSystemException catch (err) {
-      Initializer.createSessionFile(sessionFile: sessionFile);
+      final now = clock.now();
+      Initializer.createSessionFile(
+        sessionFile: sessionFile,
+        sessionIdOverride: now,
+      );
 
       _errorHandler.log(Event.analyticsException(
         workflow: 'Session._refreshSessionData',
@@ -105,7 +120,6 @@ class Session {
       ));
 
       // Fallback to setting the session id as the current time
-      final now = clock.now();
       _sessionId = now.millisecondsSinceEpoch;
     }
   }
diff --git a/pkgs/unified_analytics/test/unified_analytics_test.dart b/pkgs/unified_analytics/test/unified_analytics_test.dart
index c7ae7a387..b68b4569b 100644
--- a/pkgs/unified_analytics/test/unified_analytics_test.dart
+++ b/pkgs/unified_analytics/test/unified_analytics_test.dart
@@ -143,7 +143,7 @@ void main() {
       final timestamp = clock.now().millisecondsSinceEpoch.toString();
       expect(sessionFile.readAsStringSync(), 'contents');
       analytics.userProperty.preparePayload();
-      expect(sessionFile.readAsStringSync(), timestamp);
+      expect(sessionFile.readAsStringSync(), '{"session_id": $timestamp}');
 
       // Attempting to fetch the session id when malformed should also
       // send an error event while parsing
@@ -184,7 +184,7 @@ void main() {
     expect(errorEvent!.eventData['workflow'], 'Session._refreshSessionData');
     expect(errorEvent.eventData['error'], 'FormatException');
     expect(errorEvent.eventData['description'],
-        'message: Invalid radix-10 number\nsource: not a valid session id');
+        'message: Unexpected character\nsource: not a valid session id');
   });
 
   test('Resetting session file when file is removed', () {
@@ -199,7 +199,7 @@ void main() {
       final timestamp = clock.now().millisecondsSinceEpoch.toString();
       expect(sessionFile.existsSync(), false);
       analytics.userProperty.preparePayload();
-      expect(sessionFile.readAsStringSync(), timestamp);
+      expect(sessionFile.readAsStringSync(), '{"session_id": $timestamp}');
 
       // Attempting to fetch the session id when malformed should also
       // send an error event while parsing

From 60bc72250959b5d58e34321babe5194323f1e732 Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Mon, 4 Mar 2024 15:00:28 -0500
Subject: [PATCH 7/9] Use nullable field for `_sessionId`

---
 pkgs/unified_analytics/lib/src/analytics.dart           | 4 ++--
 pkgs/unified_analytics/lib/src/session.dart             | 5 ++---
 pkgs/unified_analytics/test/unified_analytics_test.dart | 4 ++--
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/pkgs/unified_analytics/lib/src/analytics.dart b/pkgs/unified_analytics/lib/src/analytics.dart
index 0c3a98721..74e455991 100644
--- a/pkgs/unified_analytics/lib/src/analytics.dart
+++ b/pkgs/unified_analytics/lib/src/analytics.dart
@@ -454,8 +454,8 @@ class AnalyticsImpl implements Analytics {
       errorHandler: _errorHandler,
     );
 
-    // Initialize the session handler with the session_id and last_ping
-    // variables by parsing the json file
+    // Initialize the session handler with the session_id 
+    // by parsing the json file
     _sessionHandler.initialize(telemetryEnabled);
   }
 
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index a1d57d841..3b4345288 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -19,7 +19,7 @@ class Session {
   final File sessionFile;
   final ErrorHandler _errorHandler;
 
-  int _sessionId;
+  int? _sessionId;
 
   Session({
     required this.homeDirectory,
@@ -27,7 +27,6 @@ class Session {
     required ErrorHandler errorHandler,
   })  : sessionFile = fs.file(p.join(
             homeDirectory.path, kDartToolDirectoryName, kSessionFileName)),
-        _sessionId = DateTime.now().millisecondsSinceEpoch,
         _errorHandler = errorHandler;
 
   /// This will use the data parsed from the
@@ -40,7 +39,7 @@ class Session {
   ///
   /// Note, the file will always be updated when calling this method
   /// because the last ping variable will always need to be persisted.
-  int getSessionId() {
+  int? getSessionId() {
     _refreshSessionData();
     final now = clock.now();
 
diff --git a/pkgs/unified_analytics/test/unified_analytics_test.dart b/pkgs/unified_analytics/test/unified_analytics_test.dart
index b68b4569b..8c0849338 100644
--- a/pkgs/unified_analytics/test/unified_analytics_test.dart
+++ b/pkgs/unified_analytics/test/unified_analytics_test.dart
@@ -739,7 +739,7 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
               'within the duration');
       expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
           end.millisecondsSinceEpoch,
-          reason: 'The last_ping value should have been updated');
+          reason: 'The last modified value should have been updated');
     });
   });
 
@@ -814,7 +814,7 @@ ${initialTool.label}=$dateStamp,$toolsMessageVersion
               'outside the duration');
       expect(sessionFile.lastModifiedSync().millisecondsSinceEpoch,
           end.millisecondsSinceEpoch,
-          reason: 'The last_ping value should have been updated');
+          reason: 'The last modified value should have been updated');
     });
   });
 

From ff2578aeaf3b383c04e43bcdcec88ce0167b1061 Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Mon, 4 Mar 2024 15:01:24 -0500
Subject: [PATCH 8/9] Format fix

---
 pkgs/unified_analytics/lib/src/analytics.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/unified_analytics/lib/src/analytics.dart b/pkgs/unified_analytics/lib/src/analytics.dart
index 74e455991..0a28a40c6 100644
--- a/pkgs/unified_analytics/lib/src/analytics.dart
+++ b/pkgs/unified_analytics/lib/src/analytics.dart
@@ -454,7 +454,7 @@ class AnalyticsImpl implements Analytics {
       errorHandler: _errorHandler,
     );
 
-    // Initialize the session handler with the session_id 
+    // Initialize the session handler with the session_id
     // by parsing the json file
     _sessionHandler.initialize(telemetryEnabled);
   }

From aac63d2e4dd0442e8920ce780df4abc477e76f1d Mon Sep 17 00:00:00 2001
From: eliasyishak <42216813+eliasyishak@users.noreply.github.com>
Date: Wed, 6 Mar 2024 16:27:20 -0500
Subject: [PATCH 9/9] Change to wip + use `else` block for timestamp

---
 pkgs/unified_analytics/CHANGELOG.md           | 2 +-
 pkgs/unified_analytics/lib/src/constants.dart | 2 +-
 pkgs/unified_analytics/lib/src/session.dart   | 8 ++++----
 pkgs/unified_analytics/pubspec.yaml           | 2 +-
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/pkgs/unified_analytics/CHANGELOG.md b/pkgs/unified_analytics/CHANGELOG.md
index 86fb6ac25..fd40259c2 100644
--- a/pkgs/unified_analytics/CHANGELOG.md
+++ b/pkgs/unified_analytics/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 5.8.6
+## 5.8.6-wip
 
 - Refactored session handler class to use the last modified timestamp as the last ping value
 
diff --git a/pkgs/unified_analytics/lib/src/constants.dart b/pkgs/unified_analytics/lib/src/constants.dart
index 2ab6bfe2e..e9034bbb1 100644
--- a/pkgs/unified_analytics/lib/src/constants.dart
+++ b/pkgs/unified_analytics/lib/src/constants.dart
@@ -82,7 +82,7 @@ const int kLogFileLength = 2500;
 const String kLogFileName = 'dart-flutter-telemetry.log';
 
 /// The current version of the package, should be in line with pubspec version.
-const String kPackageVersion = '5.8.6';
+const String kPackageVersion = '5.8.6-wip';
 
 /// The minimum length for a session.
 const int kSessionDurationMinutes = 30;
diff --git a/pkgs/unified_analytics/lib/src/session.dart b/pkgs/unified_analytics/lib/src/session.dart
index 3b4345288..d19b749c5 100644
--- a/pkgs/unified_analytics/lib/src/session.dart
+++ b/pkgs/unified_analytics/lib/src/session.dart
@@ -50,12 +50,12 @@ class Session {
       // Update the session file with the latest session id
       _sessionId = now.millisecondsSinceEpoch;
       sessionFile.writeAsStringSync('{"session_id": $_sessionId}');
+    } else {
+      // Update the last modified timestamp with the current timestamp so that
+      // we can use it for the next _lastPing calculation
+      sessionFile.setLastModifiedSync(now);
     }
 
-    // Update the last modified timestamp with the current timestamp so that
-    // we can use it for the next _lastPing calculation
-    sessionFile.setLastModifiedSync(now);
-
     return _sessionId;
   }
 
diff --git a/pkgs/unified_analytics/pubspec.yaml b/pkgs/unified_analytics/pubspec.yaml
index 121c92170..6c4f24809 100644
--- a/pkgs/unified_analytics/pubspec.yaml
+++ b/pkgs/unified_analytics/pubspec.yaml
@@ -4,7 +4,7 @@ description: >-
   to Google Analytics.
 # When updating this, keep the version consistent with the changelog and the
 # value in lib/src/constants.dart.
-version: 5.8.6
+version: 5.8.6-wip
 repository: https://github.com/dart-lang/tools/tree/main/pkgs/unified_analytics
 
 environment: