Added support for installing packages as optional

Delivers #2439

Added a new method to IInstaller to support marking some packages as optional.
Added a new property bool IsPartOfAnOptionalWorkload to IInstallUnityDescriptor.
Updated IInstallUnitDescriptorFactory to pipe the additional data during template installation.

Updated all the implementations of the above interfaces to comply with the changes.
Updated the tests that were broken because of the changes.

src/Microsoft.TemplateEngine.Abstractions/TemplateUpdates/IInstallUnitDescriptor.cs

@@ -21,5 +21,7 @@ public interface IInstallUnitDescriptor
         string UninstallString { get; }
 
         IReadOnlyList<string> DetailKeysDisplayOrder { get; }
+
+        bool IsPartOfAnOptionalWorkload { get; }
     }
 }

src/Microsoft.TemplateEngine.Abstractions/TemplateUpdates/IInstallUnitDescriptorFactory.cs

@@ -7,9 +7,10 @@ namespace Microsoft.TemplateEngine.Abstractions.TemplateUpdates
     public interface IInstallUnitDescriptorFactory : IIdentifiedComponent
     {
         // for existing descriptors saved in the metadata
-        bool TryCreateFromDetails(Guid descriptorId, string identifier, Guid mountPointId, IReadOnlyDictionary<string, string> details, out IInstallUnitDescriptor descriptor);
+        bool TryCreateFromDetails(Guid descriptorId, string identifier, Guid mountPointId, bool isPartOfAnOptionalWorkload,
+            IReadOnlyDictionary<string, string> details, out IInstallUnitDescriptor descriptor);
 
         // for creating from a mount point
-        bool TryCreateFromMountPoint(IMountPoint mountPoint, out IReadOnlyList<IInstallUnitDescriptor> descriptorList);
+        bool TryCreateFromMountPoint(IMountPoint mountPoint, bool isPartOfAnOptionalWorkload, out IReadOnlyList<IInstallUnitDescriptor> descriptorList);
     }
 }

src/Microsoft.TemplateEngine.Cli/IInstaller.cs

@@ -10,5 +10,7 @@ public interface IInstaller : IInstallerBase
         void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources, bool debugAllowDevInstall);
 
         void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources, bool debugAllowDevInstall, bool interactive);
+
+        void InstallPackages(IEnumerable<InstallationRequest> installationRequests, IList<string> nuGetSources = null, bool debugAllowDevInstall = false, bool interactive = false);
     }
 }

src/Microsoft.TemplateEngine.Cli/InstallationRequest.cs

@@ -0,0 +1,59 @@
+using System;
+
+namespace Microsoft.TemplateEngine.Cli
+{
+    public struct InstallationRequest : IEquatable<InstallationRequest>
+    {
+        public InstallationRequest(string installString, bool isPartOfAnOptionalWorkload = false)
+        {
+            InstallString = installString;
+            IsPartOfAnOptionalWorkload = isPartOfAnOptionalWorkload;
+        }
+
+        /// <summary>
+        /// String to identify the package/directory/archive containing the templates
+        /// </summary>
+        public string InstallString { get; set; }
+
+        /// <summary>
+        /// Is this package being installed as part of an optional workload?
+        /// </summary>
+        public bool IsPartOfAnOptionalWorkload { get; set; }
+
+        public bool Equals(InstallationRequest other)
+        {
+            return InstallString == other.InstallString &&
+                IsPartOfAnOptionalWorkload == other.IsPartOfAnOptionalWorkload;
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (!(obj is InstallationRequest other))
+            {
+                return false;
+            }
+
+            return Equals(other);
+        }
+
+        public override string ToString()
+        {
+            return $"{(IsPartOfAnOptionalWorkload ? "[OW]" : string.Empty)}{InstallString}";
+        }
+
+        public override int GetHashCode()
+        {
+            return unchecked((InstallString?.GetHashCode() ?? 0) + 13 * IsPartOfAnOptionalWorkload.GetHashCode());
+        }
+
+        public static bool operator ==(InstallationRequest x, InstallationRequest y)
+        {
+            return x.Equals(y);
+        }
+
+        public static bool operator !=(InstallationRequest x, InstallationRequest y)
+        {
+            return !(x == y);
+        }
+    }
+}

src/Microsoft.TemplateEngine.Cli/Installer.cs

@@ -1,16 +1,16 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
 using Microsoft.TemplateEngine.Abstractions;
 using Microsoft.TemplateEngine.Abstractions.Mount;
 using Microsoft.TemplateEngine.Abstractions.TemplateUpdates;
 using Microsoft.TemplateEngine.Edge;
 using Microsoft.TemplateEngine.Edge.Settings;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
 
 namespace Microsoft.TemplateEngine.Cli
 {
@@ -25,37 +25,51 @@ public Installer(IEngineEnvironmentSettings environmentSettings)
             _paths = new Paths(environmentSettings);
         }
 
-        public void AddInstallDescriptorForLocation(Guid mountPointId, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
+        public void AddInstallDescriptorForLocation(Guid mountPointId, bool isPartOfAnOptionalWorkload, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
         {
-            ((SettingsLoader)(_environmentSettings.SettingsLoader)).InstallUnitDescriptorCache.TryAddDescriptorForLocation(mountPointId, out descriptorList);
+            ((SettingsLoader)(_environmentSettings.SettingsLoader)).InstallUnitDescriptorCache.TryAddDescriptorForLocation(mountPointId, isPartOfAnOptionalWorkload, out descriptorList);
         }
 
-        public void InstallPackages(IEnumerable<string> installationRequests) => InstallPackages(installationRequests, null, false, false);
+        public void InstallPackages(IEnumerable<string> installationRequests)
+            => InstallPackages(installationRequests, null, false, false);
 
-        public void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources) => InstallPackages(installationRequests, nuGetSources, false, false);
+        public void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources)
+            => InstallPackages(installationRequests, nuGetSources, false, false);
 
-        public void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources, bool debugAllowDevInstall) => InstallPackages(installationRequests, nuGetSources, debugAllowDevInstall, false);
+        public void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources, bool debugAllowDevInstall)
+            => InstallPackages(installationRequests, nuGetSources, debugAllowDevInstall, false);
 
         public void InstallPackages(IEnumerable<string> installationRequests, IList<string> nuGetSources, bool debugAllowDevInstall, bool interactive)
+            => InstallPackages(installationRequests.Select(x => new InstallationRequest(x)), nuGetSources, debugAllowDevInstall, interactive);
+
+        public void InstallPackages(IEnumerable<InstallationRequest> installationRequests, IList<string> nuGetSources = null, bool debugAllowDevInstall = false, bool interactive = false)
         {
-            List<string> localSources = new List<string>();
+            List<InstallationRequest> localSources = new List<InstallationRequest>();
             List<Package> packages = new List<Package>();
+            List<Package> packagesFromOptionalWorkloads = new List<Package>();
 
-            foreach (string request in installationRequests)
+            foreach (InstallationRequest request in installationRequests)
             {
-                string req = request;
+                string req = request.InstallString;
 
                 //If the request string doesn't have any wild cards or probable path indicators,
                 //  and doesn't have a "::" delimiter either, try to convert it to "latest package"
                 //  form
-                if (OriginalRequestIsImplicitPackageVersionSyntax(request))
+                if (OriginalRequestIsImplicitPackageVersionSyntax(request.InstallString))
                 {
                     req += "::*";
                 }
 
                 if (Package.TryParse(req, out Package package))
                 {
-                    packages.Add(package);
+                    if (request.IsPartOfAnOptionalWorkload)
+                    {
+                        packagesFromOptionalWorkloads.Add(package);
+                    }
+                    else
+                    {
+                        packages.Add(package);
+                    }
                 }
                 else
                 {
@@ -68,10 +82,19 @@ public void InstallPackages(IEnumerable<string> installationRequests, IList<stri
                 InstallLocalPackages(localSources, debugAllowDevInstall);
             }
 
-            if (packages.Count > 0)
+            if (packages.Count + packagesFromOptionalWorkloads.Count > 0)
             {
-                IList<string> additionalDotNetArguments = (interactive) ? new string[] { "--interactive" } : null;
-                InstallRemotePackages(packages, nuGetSources, additionalDotNetArguments);
+                IList<string> additionalDotNetArguments = interactive ? new string[] { "--interactive" } : null;
+
+                if (packages.Count > 0)
+                {
+                    InstallRemotePackages(packages, nuGetSources, additionalDotNetArguments, false);
+                }
+
+                if (packagesFromOptionalWorkloads.Count > 0)
+                {
+                    InstallRemotePackages(packagesFromOptionalWorkloads, nuGetSources, additionalDotNetArguments, true);
+                }
             }
 
             _environmentSettings.SettingsLoader.Save();
@@ -197,7 +220,15 @@ private IReadOnlyCollection<Guid> GetDescendantMountPointsFromParent(Guid parent
             return mountPoints;
         }
 
-        private void InstallRemotePackages(List<Package> packages, IList<string> nuGetSources, IList<string> additionalDotNetArguments)
+        /// <summary>
+        /// Acquires given nuget packages with 'dotnet restore' and installs them.
+        /// </summary>
+        /// <param name="packages">Packages to be installed.</param>
+        /// <param name="nuGetSources">Nuget sources to look for the packages.</param>
+        /// <param name="additionalDotNetArguments">Additional arguments to be passed to 'dotnet restore'.</param>
+        /// <param name="isPartOfAnOptionalWorkload">Specifies if given packages are part of an optional workload. This should be correct for
+        /// each of the specified packages (do not mix optional and non-optional packages when calling this method).</param>
+        private void InstallRemotePackages(List<Package> packages, IList<string> nuGetSources, IList<string> additionalDotNetArguments, bool isPartOfAnOptionalWorkload)
         {
             const string packageRef = @"    <PackageReference Include=""{0}"" Version=""{1}"" />";
             const string projectFile = @"<Project ToolsVersion=""15.0"" Sdk=""Microsoft.NET.Sdk"">
@@ -250,40 +281,40 @@ private void InstallRemotePackages(List<Package> packages, IList<string> nuGetSo
             string stagingDir = Path.Combine(_paths.User.ScratchDir, "Staging");
             _paths.CreateDirectory(stagingDir);
 
-            List<string> newLocalPackages = new List<string>();
+            List<InstallationRequest> newLocalPackages = new List<InstallationRequest>();
             foreach (string packagePath in _paths.EnumerateFiles(restored, "*.nupkg", SearchOption.AllDirectories))
             {
                 string stagingPathForPackage = Path.Combine(stagingDir, Path.GetFileName(packagePath));
                 _paths.Copy(packagePath, stagingPathForPackage);
-                newLocalPackages.Add(stagingPathForPackage);
+                newLocalPackages.Add(new InstallationRequest(stagingPathForPackage, isPartOfAnOptionalWorkload));
             }
 
             InstallLocalPackages(newLocalPackages, false);
             _paths.DeleteDirectory(_paths.User.ScratchDir);
         }
 
-        private void InstallLocalPackages(IReadOnlyList<string> packageNames, bool debugAllowDevInstall)
+        private void InstallLocalPackages(IEnumerable<InstallationRequest> localInstallationRequests, bool debugAllowDevInstall)
         {
-            foreach (string package in packageNames)
+            foreach (InstallationRequest localInstallRequest in localInstallationRequests)
             {
-                if (package == null)
+                if (string.IsNullOrWhiteSpace(localInstallRequest.InstallString))
                 {
                     continue;
                 }
 
-                string pkg = package.Trim();
-                pkg = _environmentSettings.Environment.ExpandEnvironmentVariables(pkg);
+                string req = localInstallRequest.InstallString.Trim();
+                req = _environmentSettings.Environment.ExpandEnvironmentVariables(req);
                 string pattern = null;
 
-                int wildcardIndex = pkg.IndexOfAny(new[] { '*', '?' });
+                int wildcardIndex = req.IndexOfAny(new[] { '*', '?' });
 
                 if (wildcardIndex > -1)
                 {
-                    int lastSlashBeforeWildcard = pkg.LastIndexOfAny(new[] { '\\', '/' });
+                    int lastSlashBeforeWildcard = req.LastIndexOfAny(new[] { '\\', '/' });
                     if (lastSlashBeforeWildcard >= 0)
                     {
-                        pattern = pkg.Substring(lastSlashBeforeWildcard + 1);
-                        pkg = pkg.Substring(0, lastSlashBeforeWildcard);
+                        pattern = req.Substring(lastSlashBeforeWildcard + 1);
+                        req = req.Substring(0, lastSlashBeforeWildcard);
                     }
                 }
 
@@ -293,16 +324,16 @@ private void InstallLocalPackages(IReadOnlyList<string> packageNames, bool debug
 
                     if (pattern != null)
                     {
-                        string fullDirectory = new DirectoryInfo(pkg).FullName;
+                        string fullDirectory = new DirectoryInfo(req).FullName;
                         installString = Path.Combine(fullDirectory, pattern);
                     }
-                    else if (_environmentSettings.Host.FileSystem.DirectoryExists(pkg) || _environmentSettings.Host.FileSystem.FileExists(pkg))
+                    else if (_environmentSettings.Host.FileSystem.DirectoryExists(req) || _environmentSettings.Host.FileSystem.FileExists(req))
                     {
-                        installString = new DirectoryInfo(pkg).FullName;
+                        installString = new DirectoryInfo(req).FullName;
                     }
                     else
                     {
-                        _environmentSettings.Host.OnNonCriticalError("InvalidPackageSpecification", string.Format(LocalizableStrings.CouldNotFindItemToInstall, pkg), null, 0);
+                        _environmentSettings.Host.OnNonCriticalError("InvalidPackageSpecification", string.Format(LocalizableStrings.CouldNotFindItemToInstall, req), null, 0);
                     }
 
                     if (installString != null)
@@ -311,7 +342,7 @@ private void InstallLocalPackages(IReadOnlyList<string> packageNames, bool debug
 
                         foreach (Guid mountPointId in contentMountPointIds)
                         {
-                            AddInstallDescriptorForLocation(mountPointId, out IReadOnlyList<IInstallUnitDescriptor> descriptorList);
+                            AddInstallDescriptorForLocation(mountPointId, localInstallRequest.IsPartOfAnOptionalWorkload, out IReadOnlyList<IInstallUnitDescriptor> descriptorList);
 
                             foreach (IInstallUnitDescriptor descriptor in descriptorList)
                             {
@@ -322,7 +353,7 @@ private void InstallLocalPackages(IReadOnlyList<string> packageNames, bool debug
                 }
                 catch (Exception ex)
                 {
-                    _environmentSettings.Host.OnNonCriticalError("InvalidPackageSpecification", string.Format(LocalizableStrings.BadPackageSpec, pkg), null, 0);
+                    _environmentSettings.Host.OnNonCriticalError("InvalidPackageSpecification", string.Format(LocalizableStrings.BadPackageSpec, req), null, 0);
 
                     if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable("DOTNET_NEW_DEBUG")))
                     {

src/Microsoft.TemplateEngine.Edge/Settings/InstallUnitDescriptorCache.cs

@@ -41,7 +41,7 @@ public bool TryGetDescriptorForTemplate(ITemplateInfo templateInfo, out IInstall
         [JsonProperty]
         public IReadOnlyDictionary<Guid, IInstallUnitDescriptor> Descriptors => _cache;
 
-        public bool TryAddDescriptorForLocation(Guid mountPointId, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
+        public bool TryAddDescriptorForLocation(Guid mountPointId, bool isPartOfAnOptionalWorkload, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
         {
             IMountPoint mountPoint = null;
 
@@ -53,7 +53,7 @@ public bool TryAddDescriptorForLocation(Guid mountPointId, out IReadOnlyList<IIn
                     return false;
                 }
 
-                if (InstallUnitDescriptorFactory.TryCreateFromMountPoint(_environmentSettings, mountPoint, out descriptorList))
+                if (InstallUnitDescriptorFactory.TryCreateFromMountPoint(_environmentSettings, mountPoint, isPartOfAnOptionalWorkload, out descriptorList))
                 {
                     foreach (IInstallUnitDescriptor descriptor in descriptorList)
                     {

src/Microsoft.TemplateEngine.Edge/TemplateUpdates/DefaultInstallUnitDescriptor.cs

@@ -7,13 +7,14 @@ namespace Microsoft.TemplateEngine.Edge.TemplateUpdates
 {
     public sealed class DefaultInstallUnitDescriptor : IInstallUnitDescriptor
     {
-        public DefaultInstallUnitDescriptor(Guid descriptorId, Guid mountPointId, string identifier)
+        public DefaultInstallUnitDescriptor(Guid descriptorId, Guid mountPointId, string identifier, bool isPartOfAnOptionalWorkload)
         {
             DescriptorId = descriptorId;
             MountPointId = mountPointId;
             Identifier = identifier;
             Details = _details;
             DetailKeysDisplayOrder = Empty<string>.List.Value;
+            IsPartOfAnOptionalWorkload = isPartOfAnOptionalWorkload;
         }
 
         private static readonly IReadOnlyDictionary<string, string> _details = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
@@ -31,5 +32,7 @@ public DefaultInstallUnitDescriptor(Guid descriptorId, Guid mountPointId, string
         public string UninstallString => Identifier;
 
         public IReadOnlyList<string> DetailKeysDisplayOrder { get; }
+
+        public bool IsPartOfAnOptionalWorkload { get; }
     }
 }

src/Microsoft.TemplateEngine.Edge/TemplateUpdates/DefaultInstallUnitDescriptorFactory.cs

@@ -11,17 +11,18 @@ public class DefaultInstallUnitDescriptorFactory : IInstallUnitDescriptorFactory
 
         public Guid Id => FactoryId;
 
-        public bool TryCreateFromDetails(Guid descriptorId, string identifier, Guid mountPointId, IReadOnlyDictionary<string, string> details, out IInstallUnitDescriptor descriptor)
+        public bool TryCreateFromDetails(Guid descriptorId, string identifier, Guid mountPointId, bool isPartOfAnOptionalWorkload,
+            IReadOnlyDictionary<string, string> details, out IInstallUnitDescriptor descriptor)
         {
-            descriptor = new DefaultInstallUnitDescriptor(descriptorId, mountPointId, identifier);
+            descriptor = new DefaultInstallUnitDescriptor(descriptorId, mountPointId, identifier, isPartOfAnOptionalWorkload);
             return true;
         }
 
-        public bool TryCreateFromMountPoint(IMountPoint mountPoint, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
+        public bool TryCreateFromMountPoint(IMountPoint mountPoint, bool isPartOfAnOptionalWorkload, out IReadOnlyList<IInstallUnitDescriptor> descriptorList)
         {
             descriptorList = new List<IInstallUnitDescriptor>()
             {
-                new DefaultInstallUnitDescriptor(Guid.NewGuid(), mountPoint.Info.MountPointId, mountPoint.Info.Place),
+                new DefaultInstallUnitDescriptor(Guid.NewGuid(), mountPoint.Info.MountPointId, mountPoint.Info.Place, isPartOfAnOptionalWorkload),
             };
 
             return true;