improve test coverage: OpenTelemetry.Api CallerArgumentExpressionAttribute

[TimothyMothra]

Contributes to #3353
As of today;

• Overall: 85.80%
• Project: OpenTelemetry.Api: 86.85%
• File: Guard.cs: 0%

This value for Guard isn't correct. Seems that CodeCov is only counting the first class in this file.

Screenshot

Changes

• Update CallerArgumentExpressionAttribute with a link to the original implementation. link.
• Add new tests for CallerArgumentExpressionAttributeTests, borrowed from link
• Cleanup GuardTest.cs
  • move all extra classes inside public class GuardTest.
  • remove #pragma warning disable SA1402 // File may only contain a single type
  • remove #pragma warning disable SA1649 // File name should match first type name

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• Appropriate CHANGELOG.md updated for non-trivial changes
• Design discussion issue #
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #3362 (662bbf7) into main (0a4a625) will decrease coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3362      +/-   ##
==========================================
- Coverage   86.58%   86.50%   -0.09%     
==========================================
  Files         275      275              
  Lines        9978     9978              
==========================================
- Hits         8639     8631       -8     
- Misses       1339     1347       +8     

Impacted Files	Coverage Δ
src/OpenTelemetry.Api/Internal/Guard.cs	0.00% <ø> (ø)
src/OpenTelemetry/Logs/Pool/LogRecordSharedPool.cs	78.94% <0.00%> (-21.06%)	⬇️

[alanwest]

LGTM.

I am curious about

This value for Guard isn't correct. Seems that CodeCov is only counting the first class in this file.

If CallerArgumentExpressionAttribute was moved to its own file does CodeCov account for things correctly? Might be worth experimenting, but I don't feel strongly it has to block this PR.

[TimothyMothra]

If CallerArgumentExpressionAttribute was moved to its own file does CodeCov account for things correctly? Might be worth experimenting, but I don't feel strongly it has to block this PR.

We could experiment with moving CallerArgumentExpressionAttribute inside of Guard. I can look for other nested classes and see if CodeCov reports correctly.

[TimothyMothra]

I can look for other nested classes and see if CodeCov reports correctly.

I reverted the change to Guard.cs.
All the related tests failed.
We should investigate this in a separate PR.