azrepos: add cmd to clear the authority cache

Add a command to enable clearing of the Azure authority cache manually.

docs/usage.md

@@ -30,3 +30,8 @@ Read the [Git manual](https://git-scm.com/docs/gitcredentials#_custom_helpers) a
 Set your user-level Git configuration (`~/.gitconfig`) to use GCM Core. If you pass
 `--system` to these commands, they act on the system-level Git configuration
 (`/etc/gitconfig`) instead.
+
+### azure-repos (experimental)
+
+Interact with the Azure Repos host provider to manage the authentication
+authority cache.

src/shared/Microsoft.AzureRepos/AzureReposHostProvider.cs

@@ -2,6 +2,8 @@
 // Licensed under the MIT license.
 using System;
 using System.Collections.Generic;
+using System.CommandLine;
+using System.CommandLine.Invocation;
 using System.Linq;
 using System.Net.Http;
 using System.Threading.Tasks;
@@ -12,7 +14,7 @@
 
 namespace Microsoft.AzureRepos
 {
-    public class AzureReposHostProvider : DisposableObject, IHostProvider, IConfigurableComponent
+    public class AzureReposHostProvider : DisposableObject, IHostProvider, IConfigurableComponent, ICommandProvider
     {
         private readonly ICommandContext _context;
         private readonly IAzureDevOpsRestApi _azDevOps;
@@ -452,5 +454,29 @@ public Task UnconfigureAsync(ConfigurationTarget target)
         }
 
         #endregion
+
+        #region ICommandProvider
+
+        ProviderCommand ICommandProvider.CreateCommand()
+        {
+            var clearCacheCmd = new Command("clear-cache")
+            {
+                Description = "Clear the Azure authority cache",
+                Handler = CommandHandler.Create(ClearCacheCmd),
+            };
+
+            var rootCmd = new ProviderCommand(this);
+            rootCmd.AddCommand(clearCacheCmd);
+            return rootCmd;
+        }
+
+        private int ClearCacheCmd()
+        {
+            _authorityCache.Clear();
+            _context.Streams.Out.WriteLine("Authority cache cleared");
+            return 0;
+        }
+
+        #endregion
     }
 }