feat: Allow starting the SDK with an initial scope

[kabiroberai]

📜 Description

This PR adds a SentryOptions.initialScope property, enabling simple configuration of the initial scope used when starting the SDK.

💡 Motivation and Context

The reasons for this change are twofold:

1. Helps avoid the possibility of race conditions between starting the SDK and calling configureScope
2. Allows clients to pass a SentryScope subclass to override certain behaviors. For more context, see the discussion in fix: Propagate span when copying scope #2952.

There is precedent for this option; see #2952 (comment) which mentions a similar initialScope option in the JS SDK.

💚 How did you test it?

Unit tests + production app.

📝 Checklist

You have to check all boxes before merging:

• I reviewed the submitted code.
• 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.
• 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.

[brustolin]

Thanks @kabiroberai for this PR.

Looks good to me.

[philipphofmann]

Thanks for doing this, @kabiroberai. We are close, but as pointed out in the comment below, this PR doesn't align with the approach we already have on JavaScript. I'm sorry if my communication wasn't clear enough, so you now have to adapt the PR.

[philipphofmann]

h: I prefer to align with JavaScript instead of adding an extra method. We should add a method initialScope to the options, basically what we have for SentrySDK.configureScope. The public-facing API should look like this

SentrySDK.start { options in
    options.dsn = "dsn"
    options.initialScope { scope in
        scope.setEnvironment("debug")
        // ...
    }
}

I also think that the API above is cleaner than having to init the options and the scope yourself:

let options = Options()
options.dns = "dsn"

let initialScope = Scope()
scope.setEnvironment("debug")

SentrySDK.start(options: options, scope: initialScope)

[kabiroberai]

Gotcha, done! I also made it possible to pass a whole Scope object by setting initialScopeFactory directly instead of calling initialScope:, which should solve for use case 2 mentioned in the PR description.

[codecov]

Codecov Report

Merging #2982 (810ad99) into main (fd6a31c) will decrease coverage by 0.014%.
The diff coverage is 100.000%.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #2982       +/-   ##
=============================================
- Coverage   80.565%   80.552%   -0.014%     
=============================================
  Files          265       265               
  Lines        24709     24728       +19     
  Branches     10953     10963       +10     
=============================================
+ Hits         19907     19919       +12     
- Misses        4186      4191        +5     
- Partials       616       618        +2     

Impacted Files	Coverage Δ
Sources/Sentry/SentryOptions.m	97.066% <100.000%> (+0.028%)	⬆️
Sources/Sentry/SentrySDK.m	90.178% <100.000%> (+0.044%)	⬆️

... and 8 files with indirect coverage changes

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[kabiroberai]

I wonder whether we should rename this to -configureInitialScope: and rename initialScopeFactory to initialScope — @philipphofmann what do you think? EDIT: brought the API in line with the JS one.

[philipphofmann]

Thanks a lot, @kabiroberai 👏. LGTM

[philipphofmann]

The failing CI jobs have nothing to do with the changes in this PR. We have some fixes on the main branch for https://github.com/getsentry/sentry-cocoa/actions/runs/4879105885/jobs/8705357840?pr=2982, but I don't want it to block this PR.

[philipphofmann]

I will update the docs.

[philipphofmann]

Docs PR getsentry/sentry-docs#6838.