From 547db82dc925d3029a14677202e0b3ff973e43b5 Mon Sep 17 00:00:00 2001
From: Giancarlo Buenaflor <giancarlo_buenaflor@yahoo.com>
Date: Thu, 10 Oct 2024 17:11:35 +0200
Subject: [PATCH] fix(app-start): accessing null json fields from
 `fetchNativeAppStart` (#2340)

* update
---
 CHANGELOG.md                                 |  1 +
 flutter/lib/src/native/native_app_start.dart | 28 ++++++++++++++++----
 flutter/test/sentry_native_channel_test.dart | 15 +++++++++++
 3 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a156eb1f6..1933f70105 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@
 - Rounding error used on frames.total and reject frame measurements if frames.total is less than frames.slow or frames.frozen ([#2308](https://github.com/getsentry/sentry-dart/pull/2308))
 - iOS replay integration when only `onErrorSampleRate` is specified ([#2306](https://github.com/getsentry/sentry-dart/pull/2306))
 - Fix TTID timing issue ([#2326](https://github.com/getsentry/sentry-dart/pull/2326))
+- Accessing invalid json fields from `fetchNativeAppStart` should return null ([#2340](https://github.com/getsentry/sentry-dart/pull/2340))
 - Error when calling `SentryFlutter.reportFullyDisplayed()` twice ([#2339](https://github.com/getsentry/sentry-dart/pull/2339))
 
 ### Deprecate
diff --git a/flutter/lib/src/native/native_app_start.dart b/flutter/lib/src/native/native_app_start.dart
index 7b6d53422f..16723400f9 100644
--- a/flutter/lib/src/native/native_app_start.dart
+++ b/flutter/lib/src/native/native_app_start.dart
@@ -1,4 +1,5 @@
 import 'package:meta/meta.dart';
+import 'package:sentry/sentry.dart';
 
 @internal
 class NativeAppStart {
@@ -13,12 +14,29 @@ class NativeAppStart {
   bool isColdStart;
   Map<dynamic, dynamic> nativeSpanTimes;
 
-  factory NativeAppStart.fromJson(Map<String, dynamic> json) {
+  static NativeAppStart? fromJson(Map<String, dynamic> json) {
+    final appStartTime = json['appStartTime'];
+    final pluginRegistrationTime = json['pluginRegistrationTime'];
+    final isColdStart = json['isColdStart'];
+    final nativeSpanTimes = json['nativeSpanTimes'];
+
+    if (appStartTime is! double ||
+        pluginRegistrationTime is! int ||
+        isColdStart is! bool ||
+        nativeSpanTimes is! Map) {
+      // ignore: invalid_use_of_internal_member
+      Sentry.currentHub.options.logger(
+        SentryLevel.warning,
+        'Failed to parse json when capturing App Start metrics. App Start wont be reported.',
+      );
+      return null;
+    }
+
     return NativeAppStart(
-      appStartTime: json['appStartTime'] as double,
-      pluginRegistrationTime: json['pluginRegistrationTime'] as int,
-      isColdStart: json['isColdStart'] as bool,
-      nativeSpanTimes: json['nativeSpanTimes'] as Map<dynamic, dynamic>,
+      appStartTime: appStartTime,
+      pluginRegistrationTime: pluginRegistrationTime,
+      isColdStart: isColdStart,
+      nativeSpanTimes: nativeSpanTimes,
     );
   }
 }
diff --git a/flutter/test/sentry_native_channel_test.dart b/flutter/test/sentry_native_channel_test.dart
index fe5ed79dd6..0e52efbc84 100644
--- a/flutter/test/sentry_native_channel_test.dart
+++ b/flutter/test/sentry_native_channel_test.dart
@@ -52,6 +52,21 @@ void main() {
         expect(actual?.isColdStart, true);
       });
 
+      test('invalid fetchNativeAppStart returns null', () async {
+        when(channel.invokeMethod('fetchNativeAppStart'))
+            .thenAnswer((_) async => {
+                  'pluginRegistrationTime': 'invalid',
+                  'appStartTime': 'invalid',
+                  'isColdStart': 'invalid',
+                  // ignore: inference_failure_on_collection_literal
+                  'nativeSpanTimes': 'invalid',
+                });
+
+        final actual = await sut.fetchNativeAppStart();
+
+        expect(actual, isNull);
+      });
+
       test('beginNativeFrames', () async {
         when(channel.invokeMethod('beginNativeFrames'))
             .thenAnswer((realInvocation) async {});