Log exception set in IDiagnosticContext

[angularsen]

Fixes: #270
Depends on: serilog/serilog-extensions-hosting#56

Changes

• RequestLoggingMiddleware.LogCompletion enriches with the exception set in IDiagnosticContext, unless an unhandled exception takes precedence.

Testing

• Add tests on enriching with collected exception and favoring unhandled exception
• Functionally tested and Serilog request log event is correctly enriched with exception set in IDiagnosticContext

[angularsen]

Until serilog/serilog-extensions-hosting#56 is merged and the dependency version of Serilog.Extensions.Hosting is bumped, these tests will fail due to missing overload DiagnosticContextCollector.TryComplete(IEnumerable<LogEventProperty>, Exception).

[angularsen]

@nblumhardt Continuing from serilog/serilog-extensions-hosting#56 (comment):

Since the stored exception is last in wins, should any exception caught in the request handling middleware take precedence over the exception stored in the context?

In our scenario, the response pipeline looks like this:

• MVC Action throws exception A
• Hellang middleware swallows it, calls IDiagnosticContext.SetException(), sets a problem details response
• Some other middleware throws exception B
• Serilog middleware goes wut do? ¯\(ツ)/¯

Going on my gut feeling, I would expect exception B to be logged since it was thrown last in the response pipeline. Also, I believe this requires no additional change to this PR.

What do you think?

I assume a new serilog-extensions-hosting nuget must be released before this PR can pass the tests on the new SetExceptions() method.

[nblumhardt]

Sounds reasonable to me @angularsen 👍

Serilog.Extensions.Hosting 4.2.1-dev-00092 is now on NuGet and can be referenced from this repo to get the PR building 🚀

[angularsen]

@nblumhardt Rebased and upgraded to prerelease nuget, tests are now green.

[nblumhardt]

Looks good! Will be great to try this out in the wild :-)

[angularsen]

Awesome! 🎉 I will give it a spin the coming week and report back.

[angularsen]

Works like a charm!
Exception details enriched as normal when logging exceptions, plus the stacktrace at the bottom.