Add optional force parameter to func extensions install command

Author: soninaren

src/Azure.Functions.Cli/Actions/LocalActions/InstallExtensionAction.cs

@@ -21,6 +21,7 @@ internal class InstallExtensionAction : BaseAction
         public string Source { get; set; } = string.Empty;
         public string ConfigPath { get; set; } = string.Empty;
         public bool Csx { get; set; }
+        public bool Force { get; set; } = false;
 
         public InstallExtensionAction(ISecretsManager secretsManager)
         {
@@ -59,6 +60,11 @@ public override ICommandLineParserResult ParseArgs(string[] args)
                 .WithDescription("use old style csx dotnet functions")
                 .Callback(csx => Csx = csx);
 
+            Parser
+                .Setup<bool>('f', "force")
+                .WithDescription("update extensions version when running 'func extensions install'")
+                .Callback(force => Force = force);
+
             return Parser.Parse(args);
         }
 
@@ -75,9 +81,14 @@ public async override Task RunAsync()
 
                 if (string.IsNullOrEmpty(Package) && string.IsNullOrEmpty(Version))
                 {
+                    var project = ProjectHelpers.GetProject(extensionsProj);
                     foreach (var extensionPackage in ExtensionsHelper.GetExtensionPackages())
                     {
-                        await AddPackage(extensionsProj, extensionPackage.Name, extensionPackage.Version);
+                        // Only add / update package referece if it does not exist or forced update is enabled
+                        if (!ProjectHelpers.PackageReferenceExists(project, extensionPackage.Name) || Force)
+                        {
+                            await AddPackage(extensionsProj, extensionPackage.Name, extensionPackage.Version);
+                        }
                     }
                 }
                 else if (!string.IsNullOrEmpty(Package) && !string.IsNullOrEmpty(Version))

src/Azure.Functions.Cli/Common/Constants.cs

@@ -25,6 +25,7 @@ internal static class Constants
         public const string FunctionsExtensionVersion = "FUNCTIONS_EXTENSION_VERSION";
         public const string StorageEmulatorConnectionString = "UseDevelopmentStorage=true";
         public const string AzureWebJobsStorage = "AzureWebJobsStorage";
+        public const string PackageReferenceElementName = "PackageReference";
 
         public static string CliVersion => typeof(Constants).GetTypeInfo().Assembly.GetName().Version.ToString(3);
         public static string CliBetaRevision => typeof(Constants).GetTypeInfo().Assembly.GetName().Version.MinorRevision.ToString();

src/Azure.Functions.Cli/Helpers/ProjectHelpers.cs

@@ -0,0 +1,32 @@
+using System.Linq;
+using Microsoft.Build.Construction;
+using Azure.Functions.Cli.Common;
+using System.Threading.Tasks;
+using System.IO;
+using System.Xml;
+
+namespace Azure.Functions.Cli.Helpers
+{
+    internal static class ProjectHelpers
+    {
+        public static bool PackageReferenceExists(this ProjectRootElement project, string packageId)
+        {
+            ProjectItemElement existingPackageReference = project.Items
+                .FirstOrDefault(item => item.ItemType == Constants.PackageReferenceElementName && item.Include.ToLowerInvariant() == packageId.ToLowerInvariant());
+            return existingPackageReference != null;
+        }
+
+        public static ProjectRootElement GetProject(string path)
+        {
+            ProjectRootElement root = null;
+
+            if (File.Exists(path))
+            {
+                var reader = XmlTextReader.Create(new StringReader(File.ReadAllText(path)));
+                root = ProjectRootElement.Create(reader);
+            }
+
+            return root;
+        }
+    }
+}