fix: Add persistence for context to fix watchdog termination events

[philprime]

📜 Description

• Adds file persistence of the scope context to serialize for watchdog termination events

• Changes the watchdog termination scope observer as a collective entry point forwarding events to multiple processors to segment the logic into individual, testable components

• Refactors the existing breadcrumb persistence logic into a SentryWatchdogTerminationBreadcrumbProcessor. The implementation is not changed in this PR but prepared for future refactoring. A lot of the file operations are split with the SentryFileManager and would require more work.

• Adds a SentryWatchdogTerminationContextProcessor to process and persist the context to the file system. It uses the newly introduced `Sentry

• To not add even more logic to the SentryFileManager I added a wrapper store SentryScopeContextPersistentStore which handles encoding/decoding and file operations using the file manager.

• The SentryWatchdogTerminationContextProcessor is dispatching the saving via the persistent store on a background thread to reduce the impact on the main thread.

• The dispatch queue wrapper is created by the SentryDispatchFactory

In general I tried to bring a more constructor-based dependency injection style architecture into this PR, to make them replaceable and testable as individual units.

Originally the logic of SentryScopeContextPersistentStore was in the SentryWatchdogTerminationContextProcessor, therefore it's functionality is now slim and we could consider moving the method directly to the SentryWatchdogTerminationScopeObserver, but that would then. not match with the breadcrumb processor.

I believe the additional file is fine for now and can be refactored again at a future point.

💡 Motivation and Context

Closes #5182

💚 How did you test it?

📝 Checklist

You have to check all boxes before merging:

• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

Blocked by

• test: Add test target for SentryTestUtils with additional mock testing #5303
• fix: Add nullability to deserialization method #5313

[codecov]

Codecov Report

Attention: Patch coverage is 99.20692% with 11 lines in your changes missing coverage. Please review.

Project coverage is 93.002%. Comparing base (de32437) to head (212cf4f).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...tence/SentryScopeContextPersistentStoreTests.swift	98.237%	4 Missing ⚠️
...stence/TestSentryScopeContextPersistentStore.swift	60.000%	4 Missing ⚠️
...ersistence/SentryScopeContextPersistentStore.swift	97.530%	2 Missing ⚠️
Sources/Sentry/SentryDependencyContainer.m	96.000%	1 Missing ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #5242       +/-   ##
=============================================
+ Coverage   92.907%   93.002%   +0.095%     
=============================================
  Files          691       702       +11     
  Lines        86706     87873     +1167     
  Branches     31223     31528      +305     
=============================================
+ Hits         80556     81724     +1168     
+ Misses        6050      6049        -1     
  Partials       100       100               

Files with missing lines	Coverage Δ
...ors/SentryWatchdogTerminationBreadcrumbProcessor.m	100.000% <100.000%> (ø)
Sources/Sentry/SentryFileManager.m	94.460% <100.000%> (+0.023%)	⬆️
Sources/Sentry/SentrySDK.m	88.800% <100.000%> (+0.060%)	⬆️
...es/Sentry/SentryWatchdogTerminationScopeObserver.m	55.555% <100.000%> (-19.170%)	⬇️
Sources/Sentry/SentryWatchdogTerminationTracker.m	100.000% <100.000%> (ø)
...try/SentryWatchdogTerminationTrackingIntegration.m	84.285% <100.000%> (-0.090%)	⬇️
...rs/SentryWatchdogTerminationContextProcessor.swift	100.000% <100.000%> (ø)
...yTests/Helper/SentryDependencyContainerTests.swift	100.000% <100.000%> (ø)
...ts/SentryTests/Helper/SentryFileManagerTests.swift	97.106% <100.000%> (+0.059%)	⬆️
...yWatchdogTerminationBreadcrumbProcessorTests.swift	100.000% <100.000%> (ø)
... and 13 more

... and 10 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1233.39 ms	1243.00 ms	9.61 ms
Size	23.76 KiB	836.21 KiB	812.45 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
8cf5bca	1231.33 ms	1237.81 ms	6.48 ms
de033da	1206.55 ms	1217.08 ms	10.53 ms
beb7ff7	1211.40 ms	1224.12 ms	12.73 ms
5949b9e	1235.45 ms	1260.21 ms	24.76 ms
4bca912	1252.42 ms	1260.06 ms	7.64 ms
313b1d9	1240.18 ms	1258.44 ms	18.26 ms
5783680	1223.63 ms	1243.60 ms	19.97 ms
2124551	1201.23 ms	1225.34 ms	24.11 ms
b9b0f0a	1220.20 ms	1229.27 ms	9.06 ms
c0ff306	1218.92 ms	1240.64 ms	21.72 ms

App size

Revision	Plain	With Sentry	Diff
8cf5bca	21.58 KiB	671.30 KiB	649.72 KiB
de033da	21.58 KiB	418.15 KiB	396.57 KiB
beb7ff7	21.58 KiB	669.46 KiB	647.87 KiB
5949b9e	22.30 KiB	832.29 KiB	809.98 KiB
4bca912	22.85 KiB	411.14 KiB	388.29 KiB
313b1d9	22.85 KiB	414.11 KiB	391.26 KiB
5783680	21.58 KiB	714.18 KiB	692.60 KiB
2124551	22.85 KiB	411.69 KiB	388.84 KiB
b9b0f0a	20.76 KiB	434.94 KiB	414.18 KiB
c0ff306	20.76 KiB	434.65 KiB	413.89 KiB

Previous results on branch: philprime/issue-5182

Startup times

Revision	Plain	With Sentry	Diff
9b69890	1244.68 ms	1258.16 ms	13.48 ms
69ce027	1232.45 ms	1251.65 ms	19.21 ms
c34e9ed	1223.86 ms	1249.84 ms	25.98 ms
c5b273a	1212.13 ms	1235.94 ms	23.81 ms
c3fb252	1224.10 ms	1245.00 ms	20.90 ms
bcd1b71	1217.71 ms	1229.96 ms	12.25 ms
8c53c21	1223.46 ms	1246.42 ms	22.96 ms
c9efa02	1229.42 ms	1251.57 ms	22.16 ms
496853a	1225.18 ms	1244.33 ms	19.15 ms
691ac4a	1218.51 ms	1244.67 ms	26.16 ms

App size

Revision	Plain	With Sentry	Diff
9b69890	23.76 KiB	874.87 KiB	851.11 KiB
69ce027	23.76 KiB	829.42 KiB	805.66 KiB
c34e9ed	23.76 KiB	829.34 KiB	805.59 KiB
c5b273a	23.76 KiB	829.41 KiB	805.65 KiB
c3fb252	23.76 KiB	835.19 KiB	811.43 KiB
bcd1b71	23.76 KiB	829.42 KiB	805.66 KiB
8c53c21	23.76 KiB	829.42 KiB	805.66 KiB
c9efa02	23.76 KiB	829.31 KiB	805.55 KiB
496853a	23.76 KiB	830.09 KiB	806.33 KiB
691ac4a	23.76 KiB	836.21 KiB	812.45 KiB

[metcalfealex]

👋 Any idea when this fix might get merged? We are very interested in it 😄 as its blocking us from upgrading Sentry from 8.43.0 to the latest version (we are using Sentry RN and would like to upgrade to pick up the Xcode 16.3 fixes)

[philprime]

Hi @metcalfealex I believe the PR is ready for review now. As soon as my colleagues get a chance to review it, we'll make sure to merge it soon. This issue has the highest priority right now, but grew larger in size than expected.

[philipphofmann]

Thanks for integrating all the feedback. I found a few minor issues, and one important one to address before we can merge this.

[philipphofmann]

LGTM, thanks. I know that there are still a few comments to resolve, but I have no strong opinion on these. I don't want to block this PR any longer. Please let me know if you want a nother round of review.

[github-actions]

🚨 Detected changes in high risk code 🚨

High-risk code can easily blow up and is hard to test. We had severe bugs in the past. Be extra careful when changing these files, and have an extra careful look at these:

• Sources/Sentry/SentryFileManager.m

[metcalfealex]

Thanks for getting this in @philprime !

Any idea when a release will be out with this fix? To complicate things we would also need the sentry RN version to pick it up 🙏

[philprime]

@metcalfealex I'll check internally regarding any additional work that should be done before the next release and will get back to you when I have an ETA.

[philprime]

@metcalfealex we released this change in the latest version https://github.com/getsentry/sentry-cocoa/releases/tag/8.52.0

Please notice the warning on the in the release notes, as we are currently working on a hotfix 8.52.1, you might want to wait for.

[metcalfealex]

Thanks @philipphofmann! we really appreciate the quick turnaound!
btw any chance we can get a new patch release for sentry RN to pick up the patched 8.52.1 version?