Add Roslyn analyser to block DateTime Now properties

[rbev]

Follow up from #5843

Adds new entries to the BannedSymbols.txt file to discourage direct usage of certain date and time properties. Instead, it recommends using TimeProvider as a replacement.

[warwickschroeder]

Is the BannedSymbols file even used/referenced? There should be warnings but there arnt.

ServiceControl/src/ServiceControl.LicenseManagement/LicenseDetails.cs

Line 61 in 1dc6fb8

ExpirationDate = DateTime.UtcNow.Date.AddDays(-2), //HasLicenseDateExpired uses a grace period of 1 day

Also, once wired up would throw errors in CI as it treats warnings as errors.

Should "DateTime.Today" be banned as well?

[rbev]

Is the BannedSymbols file even used/referenced? There should be warnings but there arnt.

ServiceControl/src/ServiceControl.LicenseManagement/LicenseDetails.cs

Line 61 in 1dc6fb8

ExpirationDate = DateTime.UtcNow.Date.AddDays(-2), //HasLicenseDateExpired uses a grace period of 1 day

Also, once wired up would throw errors in CI as it treats warnings as errors.

Should "DateTime.Today" be banned as well?

That's so strange, I was surprised I got no errors so I added a reference, it wasn't a warning it completely failed the build locally without a #pragma. I didn't go searching, I just assumed you did an amazing job removing them all.

I'll look into why those ones don't create errors.

[johnsimons]

Shouldn't we use

dotnet_diagnostic.RS0030.severity = hint

So that devs are aware of it?

Actually, to make sure devs do the right thing, should we use inline pragmas, and not disable it in .editorconfig?

[rbev]

Abandoning as it was decided that this analyser did not provide enough value while there are so many exceptions in the project.