fix: Add null-handling for sentry level parsing

[philprime]

This PR is derived from #5572 in an effort to make the large amount of changes easier to review for #5577.

The function sentryLevelForString is used to map a NSString to a SentryLevel and expects a non-null input value.

This is an important fix, because the implementation uses SentryLevelHelper which is a Swift file, and while the Objective-C code can deal with null values, in Swift it would actually be considered force-unwrapped and crash.

sentry-cocoa/Sources/Sentry/SentryLevelMapper.m

Lines 5 to 9 in 1936411

	SentryLevel
	sentryLevelForString(NSString *string)
	{
	return [SentryLevelHelper levelForName:string];
	}

sentry-cocoa/Sources/Swift/Core/Helper/Log/SentryLevel.swift

Lines 38 to 47 in 1936411

	@objcMembers
	@_spi(Private) public class SentryLevelHelper: NSObject {
	public static func nameForLevel(_ level: SentryLevel) -> String {
	return level.description
	}
	public static func levelForName(_ name: String) -> SentryLevel {
	.fromName(name)
	}
	}

This is something we must keep in mind when bridging Objective-C files to Swift (cc @noahsmartin as you are currently most active in this field).

#skip-changelog

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.439%. Comparing base (5bf2b17) to head (ab53288).
⚠️ Report is 8 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #5803       +/-   ##
=============================================
- Coverage   86.595%   86.439%   -0.156%     
=============================================
  Files          423       423               
  Lines        36360     36349       -11     
  Branches     17178     15557     -1621     
=============================================
- Hits         31486     31420       -66     
- Misses        4827      4887       +60     
+ Partials        47        42        -5     

Files with missing lines	Coverage Δ
Sources/Sentry/SentryHub.m	98.086% <100.000%> (+0.006%)	⬆️
Sources/Sentry/SentryLevelMapper.m	100.000% <ø> (ø)
Sources/Swift/Core/Helper/Log/SentryLevel.swift	100.000% <100.000%> (ø)

... and 17 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1222.39 ms	1242.74 ms	20.36 ms
Size	23.75 KiB	913.13 KiB	889.39 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
162cd7f	1230.59 ms	1256.76 ms	26.16 ms
9add417	1224.33 ms	1243.06 ms	18.73 ms
a2a3bfb	1227.94 ms	1261.26 ms	33.32 ms
d38165b	1211.41 ms	1242.49 ms	31.08 ms
c63e0fe	1230.58 ms	1253.94 ms	23.35 ms
65ebbdb	1233.96 ms	1255.79 ms	21.83 ms
7c7ac56	1225.90 ms	1250.22 ms	24.33 ms
6d40fee	1217.47 ms	1245.37 ms	27.90 ms
4e3915a	1230.02 ms	1258.90 ms	28.88 ms
1936411	1231.51 ms	1253.27 ms	21.76 ms

App size

Revision	Plain	With Sentry	Diff
162cd7f	23.75 KiB	908.39 KiB	884.64 KiB
9add417	23.75 KiB	908.40 KiB	884.65 KiB
a2a3bfb	23.75 KiB	872.67 KiB	848.92 KiB
d38165b	23.75 KiB	855.37 KiB	831.62 KiB
c63e0fe	23.74 KiB	874.08 KiB	850.33 KiB
65ebbdb	23.75 KiB	902.33 KiB	878.59 KiB
7c7ac56	23.75 KiB	902.49 KiB	878.74 KiB
6d40fee	23.75 KiB	912.37 KiB	888.63 KiB
4e3915a	23.75 KiB	858.69 KiB	834.94 KiB
1936411	23.74 KiB	913.39 KiB	889.64 KiB

Previous results on branch: philprime/strict-nullability-14

Startup times

Revision	Plain	With Sentry	Diff
fbf9909	1221.20 ms	1239.04 ms	17.84 ms

App size

Revision	Plain	With Sentry	Diff
fbf9909	23.74 KiB	913.70 KiB	889.96 KiB

[philipphofmann]

LGTM

[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/SentrySerialization.m

[philipphofmann]

Again LGTM