PlatformNotSupportedException on MacOS via Xamarin / Make CacheChanged event configurable

[azuread]

PlatformNotSupportedException on MacOS via Xamarin / Make CacheChanged event configurable

[mrward]

Not seen this error in VS Mac.

VS Mac uses the FileSystemWatcher class from Mono for other things. I suspect this may be specific to Xamarin.Mac projects. VS Mac is a hybrid - .net framework/Xamarin.Mac project.

[mrward]

Yeah looks like it is not implemented for Xamarin.Mac projects unless they target the full framework (which is basically Mono's .NET Framework).

xamarin/xamarin-macios#5197
mono/mono#11832

[tipa]

triggering the event should be configurable, i.e. WithCacheChangedEvent() - allowing developers to disable the event themselves.

Personally, I would appreciate such an option. I do not need the "CacheChanged" event, I simply want to use the MSAL library like on Android/iOS/UWP

[tipa]

I hate to say it but it crashes again. Here logger is null which causes a NullReferenceException in TarceSourceLogger.LogError. Should have actually tested your changes - sorry 🙈

[bgavrilMS]

Interesting. A FileSystemWatcher is used to generate a "CacheChanged" event. It looks like Xamarin does not implement this class, as others have also observed here

We tested this on .net core and .net classic, but not on Mono. @crmann1, @mrward, @sgmunn - did you encounter this issue already ?

[bgavrilMS]

Easy fix would be to just swallow that exception and ignore it. In which case there the event would not fire.

More complex fixes:

• find an alternative implementation for FileSystemWatcher on Mono
• triggering the event should be configurable, i.e. WithCacheChangedEvent() - allowing developers to disable the event themselves.

[bgavrilMS]

Fixed in https://www.nuget.org/packages/Microsoft.Identity.Client.Extensions.Msal/2.10.0-preview