4320 enable warnings as errors and fix any issues

eng/Directory.Build.Common.props

@@ -22,11 +22,10 @@
 
   <PropertyGroup>
     <NoWarn>$(NoWarn);NU1507</NoWarn>
+    <NoWarn>$(NoWarn);NU1701</NoWarn>
   </PropertyGroup>
 
-  <!-- uncomment this in a new PR and fix all errors -->
-  <!-- https://github.com/Azure/azure-functions-core-tools/issues/4320 -->
-  <!-- <PropertyGroup>
+ <!--<PropertyGroup>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
-  </PropertyGroup> -->
+  </PropertyGroup> --> 
 </Project>

src/Cli/ArtifactAssembler/ArtifactAssembler.cs

@@ -277,7 +277,7 @@ private async Task CreateVisualStudioCoreToolsAsync()
             FileUtilities.CopyDirectory(inProcArtifactDirPath, createDirectory ? Path.Combine(consolidatedArtifactDirPath, Constants.InProc8DirectoryName) : consolidatedArtifactDirPath);
             Directory.Delete(inProcArtifactDirPath, true);
 
-            return (artifactDirName, consolidatedArtifactDirPath);
+            return await Task.FromResult((artifactDirName, consolidatedArtifactDirPath));
         }
 
         private async Task CreateCliCoreToolsAsync()
@@ -365,6 +365,7 @@ private async Task CreateCliCoreToolsAsync()
 
             Console.WriteLine("Finished assembling CLI Core Tools artifacts");
             Console.WriteLine();
+            await Task.CompletedTask;
         }
 
         private (string artifactDirectory, string version) GetArtifactDirectoryAndVersionNumber(string extractedRootDirectory, string artifactName)
@@ -420,6 +421,7 @@ private async Task ExtractZipFilesInDirectoryAsync(string zipSourceDir, string e
                 FileUtilities.ExtractToDirectory(zipFile, destinationDir);
                 File.Delete(zipFile);
             }
+            await Task.CompletedTask;
         }
     }
 }

src/Cli/func/Actions/HostActions/StartHostAction.cs

@@ -76,7 +76,7 @@ internal class StartHostAction : BaseAction
 
         public string JsonOutputFile { get; set; }
 
-        public string? HostRuntime { get; set; }
+        public string HostRuntime { get; set; }
 
         public StartHostAction(ISecretsManager secretsManager, IProcessManager processManager)
         {

src/Cli/func/Actions/HostActions/Startup.cs

@@ -137,7 +137,7 @@ public void Configure(IApplicationBuilder app)
                 });
             }
 
-            IApplicationLifetime applicationLifetime = app.ApplicationServices
+             IApplicationLifetime applicationLifetime = app.ApplicationServices
                 .GetRequiredService<IApplicationLifetime>();
 
             app.UseWebJobsScriptHost(applicationLifetime);

src/Cli/func/Actions/HostActions/WebHost/Security/CliAuthenticationHandler.cs

@@ -16,9 +16,10 @@ namespace Azure.Functions.Cli.Actions.HostActions.WebHost.Security
 {
     public class CliAuthenticationHandler<TOptions> : AuthenticationHandler<TOptions> where TOptions : AuthenticationSchemeOptions, new()
     {
-        public CliAuthenticationHandler(IOptionsMonitor<TOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) 
-            : base(options, logger, encoder, clock)
+        public CliAuthenticationHandler(IOptionsMonitor<TOptions> options, ILoggerFactory logger, UrlEncoder encoder, TimeProvider timeProvider) 
+            : base(options, logger, encoder)
         {
+            options.CurrentValue.TimeProvider = timeProvider;
         }
 
         protected override Task<AuthenticateResult> HandleAuthenticateAsync()

src/Cli/func/ConsoleApp.cs

@@ -373,7 +373,7 @@ internal IAction Parse()
                     return action;
                 }
             }
-            catch (CliArgumentsException ex)
+            catch (CliArgumentsException)
             {
                 // TODO: we can probably display help here as well.
                 // This happens for actions that expect an ordered untyped options.

src/Cli/func/Helpers/RetryHelper.cs

@@ -24,7 +24,7 @@ public static async Task Retry(Func<Task> func, int retryCount, TimeSpan retryDe
                 {
                     if (retryCount <= 0)
                     {
-                        throw e;
+                        throw;
                     }
                     retryCount--;
                     if (displayError)
@@ -50,7 +50,7 @@ public static async Task<T> Retry<T>(Func<Task<T>> func, int retryCount, TimeSpa
                 {
                     if (retryCount <= 0)
                     {
-                        throw e;
+                        throw;
                     }
                     retryCount--;
                     if (displayError)

src/Cli/func/Telemetry/ExternalTelemetryProperties.cs

@@ -24,17 +24,14 @@ internal static class ExternalTelemetryProperties
         /// </summary>
         internal static string GetInstallationType()
         {
-            if (RuntimeEnvironment.OperatingSystemPlatform != Platform.Windows)
-            {
-                return "";
-            }
-
             const string Key = @"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion";
             const string ValueName = @"InstallationType";
 
             try
             {
-                return (string)Registry.GetValue(Key, ValueName, defaultValue: "");
+                return RuntimeInformation.IsOSPlatform(OSPlatform.Windows) 
+                    ? Registry.GetValue(Key, ValueName, defaultValue: "") as string
+                    : "";
             }
             // Catch everything: this is for telemetry only.
             catch (Exception e)

src/Cli/func/Telemetry/Telemetry.cs

@@ -92,10 +92,13 @@ private void InitializeTelemetry()
             {
                 var persistenceChannel = new PersistenceChannel.PersistenceChannel(sendersCount: _senderCount);
                 persistenceChannel.SendingInterval = TimeSpan.FromMilliseconds(1);
-                TelemetryConfiguration.Active.TelemetryChannel = persistenceChannel;
+                var telemetryConfiguration = new TelemetryConfiguration
+                {
+                    TelemetryChannel = persistenceChannel,
+                    ConnectionString = $"InstrumentationKey={Constants.TelemetryInstrumentationKey}"
+                };
 
-                _client = new TelemetryClient();
-                _client.InstrumentationKey = Constants.TelemetryInstrumentationKey;
+                _client = new TelemetryClient(telemetryConfiguration);
                 _client.Context.Session.Id = CurrentSessionId;
                 _client.Context.Device.OperatingSystem = RuntimeEnvironment.OperatingSystem;
 

src/CoreToolsHost/AppLoader/HostFxr.cs

@@ -12,6 +12,13 @@ public unsafe struct hostfxr_initialize_parameters
             public nint size;
             public char* host_path;
             public char* dotnet_root;
+
+            public hostfxr_initialize_parameters()
+            {
+                size = sizeof(hostfxr_initialize_parameters);
+                host_path = null;
+                dotnet_root = null;
+            }
         };
 
         [LibraryImport("hostfxr", EntryPoint = "hostfxr_initialize_for_dotnet_command_line",

src/CoreToolsHost/LocalSettingsJsonParser.cs

@@ -9,7 +9,7 @@ namespace CoreToolsHost
 {
     internal static class LocalSettingsJsonParser
     {
-        internal static async Task<JsonDocument> GetLocalSettingsJsonAsJObjectAsync()
+        internal static async Task<JsonDocument?> GetLocalSettingsJsonAsJObjectAsync()
         {
             var fullPath = Path.Combine(Environment.CurrentDirectory, "local.settings.json");