More package creation updates

nkolev92 · nkolev92 · commit 79be6ed902f0 · 2026-03-17T11:11:51.000-07:00
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/IPackageMetadata.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/IPackageMetadata.cs
@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using NuGet.Packaging.Core;
@@ -12,26 +10,26 @@ namespace NuGet.Packaging
 {
     public interface IPackageMetadata
     {
-        string Id { get; }
-        NuGetVersion Version { get; }
+        string? Id { get; }
+        NuGetVersion? Version { get; }
 
-        string Title { get; }
+        string? Title { get; }
         IEnumerable<string> Authors { get; }
         IEnumerable<string> Owners { get; }
-        Uri IconUrl { get; }
-        Uri LicenseUrl { get; }
-        Uri ProjectUrl { get; }
+        Uri? IconUrl { get; }
+        Uri? LicenseUrl { get; }
+        Uri? ProjectUrl { get; }
         bool RequireLicenseAcceptance { get; }
         bool DevelopmentDependency { get; }
-        string Description { get; }
-        string Summary { get; }
-        string ReleaseNotes { get; }
-        string Language { get; }
-        string Tags { get; }
+        string? Description { get; }
+        string? Summary { get; }
+        string? ReleaseNotes { get; }
+        string? Language { get; }
+        string? Tags { get; }
         bool Serviceable { get; }
-        string Copyright { get; }
-        string Icon { get; }
-        string Readme { get; }
+        string? Copyright { get; }
+        string? Icon { get; }
+        string? Readme { get; }
 
         /// <summary>
         /// Specifies assemblies from GAC that the package depends on.
@@ -48,7 +46,7 @@ public interface IPackageMetadata
         /// </summary>
         IEnumerable<PackageDependencyGroup> DependencyGroups { get; }
 
-        Version MinClientVersion { get; }
+        Version? MinClientVersion { get; }
 
         /// <summary>
         /// Returns sets of Content Files specified in the manifest.
@@ -57,9 +55,9 @@ public interface IPackageMetadata
 
         IEnumerable<PackageType> PackageTypes { get; }
 
-        RepositoryMetadata Repository { get; }
+        RepositoryMetadata? Repository { get; }
 
-        LicenseMetadata LicenseMetadata { get; }
+        LicenseMetadata? LicenseMetadata { get; }
 
         IEnumerable<FrameworkReferenceGroup> FrameworkReferenceGroups { get; }
     }
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/LicenseMetadata.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/LicenseMetadata.cs
@@ -91,7 +91,7 @@ public override int GetHashCode()
             return combiner.CombinedHash;
         }
 
-        public Uri? LicenseUrl
+        public Uri LicenseUrl
         {
             get
             {
@@ -104,7 +104,7 @@ public Uri? LicenseUrl
                         return new Uri(GenerateLicenseServiceLink(License));
 
                     default:
-                        return null;
+                        throw new NotSupportedException($"Unsupported license type: {Type}");
                 }
             }
         }
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/ManifestSchemaUtility.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/ManifestSchemaUtility.cs
@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Globalization;
 using System.Linq;
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/ManifestVersionUtility.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Authoring/ManifestVersionUtility.cs
@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Linq;
 
diff --git a/src/NuGet.Core/NuGet.Packaging/PackageCreation/Xml/PackageMetadataXmlExtensions.cs b/src/NuGet.Core/NuGet.Packaging/PackageCreation/Xml/PackageMetadataXmlExtensions.cs
@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -138,11 +136,11 @@ public static XElement ToXElement(this ManifestMetadata metadata, XNamespace ns,
             return elem;
         }
 
-        private static XElement GetXElementFromGroupableItemSets<TSet, TItem>(
+        private static XElement? GetXElementFromGroupableItemSets<TSet, TItem>(
             XNamespace ns,
             IEnumerable<TSet> objectSets,
             Func<TSet, bool> isGroupable,
-            Func<TSet, string> getGroupIdentifer,
+            Func<TSet, string?> getGroupIdentifer,
             Func<TSet, IEnumerable<TItem>> getItems,
             Func<XNamespace, TItem, XElement> getXElementFromItem,
             string parentName,
@@ -233,7 +231,7 @@ private static XElement GetXElementFromPackageDependency(XNamespace ns, PackageD
             return new XElement(ns + "dependency", attributes);
         }
 
-        private static XElement GetXElementFromFrameworkAssemblies(XNamespace ns, IEnumerable<FrameworkAssemblyReference> references)
+        private static XElement? GetXElementFromFrameworkAssemblies(XNamespace ns, IEnumerable<FrameworkAssemblyReference> references)
         {
             if (references == null || !references.Any())
             {
@@ -250,7 +248,7 @@ private static XElement GetXElementFromFrameworkAssemblies(XNamespace ns, IEnume
                             null)));
         }
 
-        private static XElement GetXElementFromManifestContentFiles(XNamespace ns, IEnumerable<ManifestContentFiles> contentFiles)
+        private static XElement? GetXElementFromManifestContentFiles(XNamespace ns, IEnumerable<ManifestContentFiles> contentFiles)
         {
             if (contentFiles == null || !contentFiles.Any())
             {
@@ -263,34 +261,32 @@ private static XElement GetXElementFromManifestContentFiles(XNamespace ns, IEnum
 
         private static XElement GetXElementFromManifestContentFile(XNamespace ns, ManifestContentFiles file)
         {
-            var attributes = new List<XAttribute>();
-
-            attributes.Add(GetXAttributeFromNameAndValue("include", file.Include));
-            attributes.Add(GetXAttributeFromNameAndValue("exclude", file.Exclude));
-            attributes.Add(GetXAttributeFromNameAndValue("buildAction", file.BuildAction));
-            attributes.Add(GetXAttributeFromNameAndValue("copyToOutput", file.CopyToOutput));
-            attributes.Add(GetXAttributeFromNameAndValue("flatten", file.Flatten));
-
-            attributes = attributes.Where(xAtt => xAtt != null).ToList();
-
-            return new XElement(ns + Files, attributes);
+            var attributes = new List<XAttribute?>
+            {
+                GetXAttributeFromNameAndValue("include", file.Include),
+                GetXAttributeFromNameAndValue("exclude", file.Exclude),
+                GetXAttributeFromNameAndValue("buildAction", file.BuildAction),
+                GetXAttributeFromNameAndValue("copyToOutput", file.CopyToOutput),
+                GetXAttributeFromNameAndValue("flatten", file.Flatten)
+            };
+
+            return new XElement(ns + Files, attributes.Where(xAtt => xAtt != null));
         }
 
         private static XElement GetXElementFromLicenseMetadata(XNamespace ns, LicenseMetadata metadata)
         {
-            var attributes = new List<XAttribute>();
+            var attributes = new List<XAttribute?>();
 
             attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Type, metadata.Type.ToString().ToLowerInvariant()));
             if (!metadata.Version.Equals(LicenseMetadata.EmptyVersion))
             {
                 attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Version, metadata.Version));
             }
-            attributes = attributes.Where(xAtt => xAtt != null).ToList();
 
-            return new XElement(ns + NuspecUtility.License, metadata.License, attributes);
+            return new XElement(ns + NuspecUtility.License, metadata.License, attributes.Where(xAtt => xAtt != null));
         }
 
-        private static XElement GetXElementFromManifestRepository(XNamespace ns, RepositoryMetadata repository)
+        private static XElement? GetXElementFromManifestRepository(XNamespace ns, RepositoryMetadata repository)
         {
             var attributeList = new List<XAttribute>();
             if (repository != null && !string.IsNullOrEmpty(repository.Type))
@@ -305,12 +301,12 @@ private static XElement GetXElementFromManifestRepository(XNamespace ns, Reposit
 
             if (!string.IsNullOrEmpty(repository?.Branch))
             {
-                attributeList.Add(new XAttribute(NuspecUtility.RepositoryBranch, repository.Branch));
+                attributeList.Add(new XAttribute(NuspecUtility.RepositoryBranch, repository!.Branch!));
             }
 
             if (!string.IsNullOrEmpty(repository?.Commit))
             {
-                attributeList.Add(new XAttribute(NuspecUtility.RepositoryCommit, repository.Commit));
+                attributeList.Add(new XAttribute(NuspecUtility.RepositoryCommit, repository!.Commit!));
             }
 
             if (attributeList.Count > 0)
@@ -335,20 +331,18 @@ private static XElement GetXElementFromManifestPackageTypes(XNamespace ns, IEnum
 
         private static XElement GetXElementFromManifestPackageType(XNamespace ns, PackageType packageType)
         {
-            var attributes = new List<XAttribute>();
+            var attributes = new List<XAttribute?>();
 
             attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Name, packageType.Name));
             if (packageType.Version != PackageType.EmptyVersion)
             {
                 attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Version, packageType.Version));
             }
 
-            attributes = attributes.Where(xAtt => xAtt != null).ToList();
-
-            return new XElement(ns + NuspecUtility.PackageType, attributes);
+            return new XElement(ns + NuspecUtility.PackageType, attributes.Where(xAtt => xAtt != null));
         }
 
-        private static XAttribute GetXAttributeFromNameAndValue(string name, object value)
+        private static XAttribute? GetXAttributeFromNameAndValue(string name, object? value)
         {
             if (name == null || value == null)
             {
@@ -358,7 +352,7 @@ private static XAttribute GetXAttributeFromNameAndValue(string name, object valu
             return new XAttribute(name, value);
         }
 
-        private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T value)
+        private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T? value)
             where T : class
         {
             if (value != null)
@@ -367,7 +361,7 @@ private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, strin
             }
         }
 
-        private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T value, Func<T, object> process)
+        private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T? value, Func<T, object> process)
             where T : class
         {
             if (value != null)
diff --git a/src/NuGet.Core/NuGet.Packaging/PublicAPI/net472/PublicAPI.Shipped.txt b/src/NuGet.Core/NuGet.Packaging/PublicAPI/net472/PublicAPI.Shipped.txt
@@ -331,7 +331,7 @@ NuGet.Packaging.LicenseMetadata.Equals(NuGet.Packaging.LicenseMetadata? other) -
 NuGet.Packaging.LicenseMetadata.License.get -> string!
 NuGet.Packaging.LicenseMetadata.LicenseExpression.get -> NuGet.Packaging.Licenses.NuGetLicenseExpression?
 NuGet.Packaging.LicenseMetadata.LicenseMetadata(NuGet.Packaging.LicenseType type, string! license, NuGet.Packaging.Licenses.NuGetLicenseExpression? expression, System.Collections.Generic.IReadOnlyList<string!>? warningsAndErrors, System.Version! version) -> void
-NuGet.Packaging.LicenseMetadata.LicenseUrl.get -> System.Uri?
+NuGet.Packaging.LicenseMetadata.LicenseUrl.get -> System.Uri!
 NuGet.Packaging.LicenseMetadata.Type.get -> NuGet.Packaging.LicenseType
 NuGet.Packaging.LicenseMetadata.Version.get -> System.Version!
 NuGet.Packaging.LicenseMetadata.WarningsAndErrors.get -> System.Collections.Generic.IReadOnlyList<string!>?
@@ -1538,11 +1538,11 @@ static NuGet.Packaging.Licenses.NuGetLicenseExpressionExtensions.OnEachLeafNode(
 ~static NuGet.Packaging.Manifest.ReadFrom(System.IO.Stream stream, System.Func<string, string> propertyProvider, bool validateSchema) -> NuGet.Packaging.Manifest
 ~static NuGet.Packaging.Manifest.ReadFrom(System.IO.Stream stream, bool validateSchema) -> NuGet.Packaging.Manifest
 ~static NuGet.Packaging.Manifest.Validate(NuGet.Packaging.Manifest manifest) -> void
-~static NuGet.Packaging.ManifestSchemaUtility.GetManifestSchemaSet(string schemaNamespace) -> System.Xml.Schema.XmlSchemaSet
-~static NuGet.Packaging.ManifestSchemaUtility.GetSchemaNamespace(int version) -> string
-~static NuGet.Packaging.ManifestSchemaUtility.GetVersionFromNamespace(string namespace) -> int
-~static NuGet.Packaging.ManifestSchemaUtility.IsKnownSchema(string schemaNamespace) -> bool
-~static NuGet.Packaging.ManifestVersionUtility.GetManifestVersion(NuGet.Packaging.ManifestMetadata metadata) -> int
+static NuGet.Packaging.ManifestSchemaUtility.GetManifestSchemaSet(string! schemaNamespace) -> System.Xml.Schema.XmlSchemaSet!
+static NuGet.Packaging.ManifestSchemaUtility.GetSchemaNamespace(int version) -> string!
+static NuGet.Packaging.ManifestSchemaUtility.GetVersionFromNamespace(string! namespace) -> int
+static NuGet.Packaging.ManifestSchemaUtility.IsKnownSchema(string! schemaNamespace) -> bool
+static NuGet.Packaging.ManifestVersionUtility.GetManifestVersion(NuGet.Packaging.ManifestMetadata! metadata) -> int
 static NuGet.Packaging.MinClientVersionUtility.GetNuGetClientVersion() -> NuGet.Versioning.NuGetVersion!
 static NuGet.Packaging.MinClientVersionUtility.IsMinClientVersionCompatible(NuGet.Packaging.Core.NuspecCoreReaderBase! nuspecReader) -> bool
 static NuGet.Packaging.MinClientVersionUtility.IsMinClientVersionCompatible(NuGet.Versioning.NuGetVersion! packageMinClientVersion) -> bool
diff --git a/src/NuGet.Core/NuGet.Packaging/PublicAPI/net472/PublicAPI.Unshipped.txt b/src/NuGet.Core/NuGet.Packaging/PublicAPI/net472/PublicAPI.Unshipped.txt
@@ -1,4 +1,29 @@
 #nullable enable
+NuGet.Packaging.IPackageMetadata.Authors.get -> System.Collections.Generic.IEnumerable<string!>!
+NuGet.Packaging.IPackageMetadata.ContentFiles.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.ManifestContentFiles!>!
+NuGet.Packaging.IPackageMetadata.Copyright.get -> string?
+NuGet.Packaging.IPackageMetadata.DependencyGroups.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.PackageDependencyGroup!>!
+NuGet.Packaging.IPackageMetadata.Description.get -> string?
+NuGet.Packaging.IPackageMetadata.FrameworkReferenceGroups.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.FrameworkReferenceGroup!>!
+NuGet.Packaging.IPackageMetadata.FrameworkReferences.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.FrameworkAssemblyReference!>!
+NuGet.Packaging.IPackageMetadata.Icon.get -> string?
+NuGet.Packaging.IPackageMetadata.IconUrl.get -> System.Uri?
+NuGet.Packaging.IPackageMetadata.Id.get -> string?
+NuGet.Packaging.IPackageMetadata.Language.get -> string?
+NuGet.Packaging.IPackageMetadata.LicenseMetadata.get -> NuGet.Packaging.LicenseMetadata?
+NuGet.Packaging.IPackageMetadata.LicenseUrl.get -> System.Uri?
+NuGet.Packaging.IPackageMetadata.MinClientVersion.get -> System.Version?
+NuGet.Packaging.IPackageMetadata.Owners.get -> System.Collections.Generic.IEnumerable<string!>!
+NuGet.Packaging.IPackageMetadata.PackageAssemblyReferences.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.PackageReferenceSet!>!
+NuGet.Packaging.IPackageMetadata.PackageTypes.get -> System.Collections.Generic.IEnumerable<NuGet.Packaging.Core.PackageType!>!
+NuGet.Packaging.IPackageMetadata.ProjectUrl.get -> System.Uri?
+NuGet.Packaging.IPackageMetadata.Readme.get -> string?
+NuGet.Packaging.IPackageMetadata.ReleaseNotes.get -> string?
+NuGet.Packaging.IPackageMetadata.Repository.get -> NuGet.Packaging.Core.RepositoryMetadata?
+NuGet.Packaging.IPackageMetadata.Summary.get -> string?
+NuGet.Packaging.IPackageMetadata.Tags.get -> string?
+NuGet.Packaging.IPackageMetadata.Title.get -> string?
+NuGet.Packaging.IPackageMetadata.Version.get -> NuGet.Versioning.NuGetVersion?
 ~NuGet.Packaging.PackageBuilder.PackageBuilder(string path, string basePath, System.Func<string, string> propertyProvider, bool includeEmptyDirectories, bool deterministic, NuGet.Common.ILogger logger, string versionOverride) -> void
 ~NuGet.Packaging.PackageBuilder.PackageBuilder(string path, string basePath, System.Func<string, string> propertyProvider, bool includeEmptyDirectories, bool deterministic, string versionOverride) -> void
 ~NuGet.Packaging.PackageBuilder.PackageBuilder(string path, System.Func<string, string> propertyProvider, bool includeEmptyDirectories, bool deterministic, NuGet.Common.ILogger logger, string versionOverride) -> void
diff --git a/src/NuGet.Core/NuGet.Packaging/PublicAPI/net8.0/PublicAPI.Shipped.txt b/src/NuGet.Core/NuGet.Packaging/PublicAPI/net8.0/PublicAPI.Shipped.txt
@@ -331,7 +331,7 @@ NuGet.Packaging.LicenseMetadata.Equals(NuGet.Packaging.LicenseMetadata? other) -
 NuGet.Packaging.LicenseMetadata.License.get -> string!
 NuGet.Packaging.LicenseMetadata.LicenseExpression.get -> NuGet.Packaging.Licenses.NuGetLicenseExpression?
 NuGet.Packaging.LicenseMetadata.LicenseMetadata(NuGet.Packaging.LicenseType type, string! license, NuGet.Packaging.Licenses.NuGetLicenseExpression? expression, System.Collections.Generic.IReadOnlyList<string!>? warningsAndErrors, System.Version! version) -> void
-NuGet.Packaging.LicenseMetadata.LicenseUrl.get -> System.Uri?
+NuGet.Packaging.LicenseMetadata.LicenseUrl.get -> System.Uri!
 NuGet.Packaging.LicenseMetadata.Type.get -> NuGet.Packaging.LicenseType
 NuGet.Packaging.LicenseMetadata.Version.get -> System.Version!
 NuGet.Packaging.LicenseMetadata.WarningsAndErrors.get -> System.Collections.Generic.IReadOnlyList<string!>?
@@ -1523,10 +1523,10 @@ static NuGet.Packaging.Licenses.NuGetLicenseExpressionExtensions.OnEachLeafNode(
 ~static NuGet.Packaging.Manifest.ReadFrom(System.IO.Stream stream, System.Func<string, string> propertyProvider, bool validateSchema) -> NuGet.Packaging.Manifest
 ~static NuGet.Packaging.Manifest.ReadFrom(System.IO.Stream stream, bool validateSchema) -> NuGet.Packaging.Manifest
 ~static NuGet.Packaging.Manifest.Validate(NuGet.Packaging.Manifest manifest) -> void
-~static NuGet.Packaging.ManifestSchemaUtility.GetSchemaNamespace(int version) -> string
-~static NuGet.Packaging.ManifestSchemaUtility.GetVersionFromNamespace(string namespace) -> int
-~static NuGet.Packaging.ManifestSchemaUtility.IsKnownSchema(string schemaNamespace) -> bool
-~static NuGet.Packaging.ManifestVersionUtility.GetManifestVersion(NuGet.Packaging.ManifestMetadata metadata) -> int
+static NuGet.Packaging.ManifestSchemaUtility.GetSchemaNamespace(int version) -> string!
+static NuGet.Packaging.ManifestSchemaUtility.GetVersionFromNamespace(string! namespace) -> int
+static NuGet.Packaging.ManifestSchemaUtility.IsKnownSchema(string! schemaNamespace) -> bool
+static NuGet.Packaging.ManifestVersionUtility.GetManifestVersion(NuGet.Packaging.ManifestMetadata! metadata) -> int
 static NuGet.Packaging.MinClientVersionUtility.GetNuGetClientVersion() -> NuGet.Versioning.NuGetVersion!
 static NuGet.Packaging.MinClientVersionUtility.IsMinClientVersionCompatible(NuGet.Packaging.Core.NuspecCoreReaderBase! nuspecReader) -> bool
 static NuGet.Packaging.MinClientVersionUtility.IsMinClientVersionCompatible(NuGet.Versioning.NuGetVersion! packageMinClientVersion) -> bool
diff --git a/src/NuGet.Core/NuGet.Packaging/PublicAPI/net8.0/PublicAPI.Unshipped.txt b/src/NuGet.Core/NuGet.Packaging/PublicAPI/net8.0/PublicAPI.Unshipped.txt

Original file line number	Diff line number	Diff line change
`@@ -91,7 +91,7 @@ public override int GetHashCode()`
`91`	`91`	`return combiner.CombinedHash;`
`92`	`92`	`}`
`93`	`93`
`94`		`- public Uri? LicenseUrl`
	`94`	`+ public Uri LicenseUrl`
`95`	`95`	`{`
`96`	`96`	`get`
`97`	`97`	`{`
`@@ -104,7 +104,7 @@ public Uri? LicenseUrl`
`104`	`104`	`return new Uri(GenerateLicenseServiceLink(License));`
`105`	`105`
`106`	`106`	`default:`
`107`		`- return null;`
	`107`	`+ throw new NotSupportedException($"Unsupported license type: {Type}");`
`108`	`108`	`}`
`109`	`109`	`}`
`110`	`110`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,8 +1,6 @@`
`1`	`1`	`// Copyright (c) .NET Foundation. All rights reserved.`
`2`	`2`	`// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.`
`3`	`3`
`4`		`-#nullable disable`
`5`		`-`
`6`	`4`	`using System;`
`7`	`5`	`using System.Collections.Generic;`
`8`	`6`	`using System.Linq;`
`@@ -138,11 +136,11 @@ public static XElement ToXElement(this ManifestMetadata metadata, XNamespace ns,`
`138`	`136`	`return elem;`
`139`	`137`	`}`
`140`	`138`
`141`		`- private static XElement GetXElementFromGroupableItemSets<TSet, TItem>(`
	`139`	`+ private static XElement? GetXElementFromGroupableItemSets<TSet, TItem>(`
`142`	`140`	`XNamespace ns,`
`143`	`141`	`IEnumerable<TSet> objectSets,`
`144`	`142`	`Func<TSet, bool> isGroupable,`
`145`		`- Func<TSet, string> getGroupIdentifer,`
	`143`	`+ Func<TSet, string?> getGroupIdentifer,`
`146`	`144`	`Func<TSet, IEnumerable<TItem>> getItems,`
`147`	`145`	`Func<XNamespace, TItem, XElement> getXElementFromItem,`
`148`	`146`	`string parentName,`
`@@ -233,7 +231,7 @@ private static XElement GetXElementFromPackageDependency(XNamespace ns, PackageD`
`233`	`231`	`return new XElement(ns + "dependency", attributes);`
`234`	`232`	`}`
`235`	`233`
`236`		`- private static XElement GetXElementFromFrameworkAssemblies(XNamespace ns, IEnumerable<FrameworkAssemblyReference> references)`
	`234`	`+ private static XElement? GetXElementFromFrameworkAssemblies(XNamespace ns, IEnumerable<FrameworkAssemblyReference> references)`
`237`	`235`	`{`
`238`	`236`	`if (references == null \|\| !references.Any())`
`239`	`237`	`{`
`@@ -250,7 +248,7 @@ private static XElement GetXElementFromFrameworkAssemblies(XNamespace ns, IEnume`
`250`	`248`	`null)));`
`251`	`249`	`}`
`252`	`250`
`253`		`- private static XElement GetXElementFromManifestContentFiles(XNamespace ns, IEnumerable<ManifestContentFiles> contentFiles)`
	`251`	`+ private static XElement? GetXElementFromManifestContentFiles(XNamespace ns, IEnumerable<ManifestContentFiles> contentFiles)`
`254`	`252`	`{`
`255`	`253`	`if (contentFiles == null \|\| !contentFiles.Any())`
`256`	`254`	`{`
`@@ -263,34 +261,32 @@ private static XElement GetXElementFromManifestContentFiles(XNamespace ns, IEnum`
`263`	`261`
`264`	`262`	`private static XElement GetXElementFromManifestContentFile(XNamespace ns, ManifestContentFiles file)`
`265`	`263`	`{`
`266`		`- var attributes = new List<XAttribute>();`
`267`		`-`
`268`		`- attributes.Add(GetXAttributeFromNameAndValue("include", file.Include));`
`269`		`- attributes.Add(GetXAttributeFromNameAndValue("exclude", file.Exclude));`
`270`		`- attributes.Add(GetXAttributeFromNameAndValue("buildAction", file.BuildAction));`
`271`		`- attributes.Add(GetXAttributeFromNameAndValue("copyToOutput", file.CopyToOutput));`
`272`		`- attributes.Add(GetXAttributeFromNameAndValue("flatten", file.Flatten));`
`273`		`-`
`274`		`- attributes = attributes.Where(xAtt => xAtt != null).ToList();`
`275`		`-`
`276`		`- return new XElement(ns + Files, attributes);`
	`264`	`+ var attributes = new List<XAttribute?>`
	`265`	`+ {`
	`266`	`+ GetXAttributeFromNameAndValue("include", file.Include),`
	`267`	`+ GetXAttributeFromNameAndValue("exclude", file.Exclude),`
	`268`	`+ GetXAttributeFromNameAndValue("buildAction", file.BuildAction),`
	`269`	`+ GetXAttributeFromNameAndValue("copyToOutput", file.CopyToOutput),`
	`270`	`+ GetXAttributeFromNameAndValue("flatten", file.Flatten)`
	`271`	`+ };`
	`272`	`+`
	`273`	`+ return new XElement(ns + Files, attributes.Where(xAtt => xAtt != null));`
`277`	`274`	`}`
`278`	`275`
`279`	`276`	`private static XElement GetXElementFromLicenseMetadata(XNamespace ns, LicenseMetadata metadata)`
`280`	`277`	`{`
`281`		`- var attributes = new List<XAttribute>();`
	`278`	`+ var attributes = new List<XAttribute?>();`
`282`	`279`
`283`	`280`	`attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Type, metadata.Type.ToString().ToLowerInvariant()));`
`284`	`281`	`if (!metadata.Version.Equals(LicenseMetadata.EmptyVersion))`
`285`	`282`	`{`
`286`	`283`	`attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Version, metadata.Version));`
`287`	`284`	`}`
`288`		`- attributes = attributes.Where(xAtt => xAtt != null).ToList();`
`289`	`285`
`290`		`- return new XElement(ns + NuspecUtility.License, metadata.License, attributes);`
	`286`	`+ return new XElement(ns + NuspecUtility.License, metadata.License, attributes.Where(xAtt => xAtt != null));`
`291`	`287`	`}`
`292`	`288`
`293`		`- private static XElement GetXElementFromManifestRepository(XNamespace ns, RepositoryMetadata repository)`
	`289`	`+ private static XElement? GetXElementFromManifestRepository(XNamespace ns, RepositoryMetadata repository)`
`294`	`290`	`{`
`295`	`291`	`var attributeList = new List<XAttribute>();`
`296`	`292`	`if (repository != null && !string.IsNullOrEmpty(repository.Type))`
`@@ -305,12 +301,12 @@ private static XElement GetXElementFromManifestRepository(XNamespace ns, Reposit`
`305`	`301`
`306`	`302`	`if (!string.IsNullOrEmpty(repository?.Branch))`
`307`	`303`	`{`
`308`		`- attributeList.Add(new XAttribute(NuspecUtility.RepositoryBranch, repository.Branch));`
	`304`	`+ attributeList.Add(new XAttribute(NuspecUtility.RepositoryBranch, repository!.Branch!));`
`309`	`305`	`}`
`310`	`306`
`311`	`307`	`if (!string.IsNullOrEmpty(repository?.Commit))`
`312`	`308`	`{`
`313`		`- attributeList.Add(new XAttribute(NuspecUtility.RepositoryCommit, repository.Commit));`
	`309`	`+ attributeList.Add(new XAttribute(NuspecUtility.RepositoryCommit, repository!.Commit!));`
`314`	`310`	`}`
`315`	`311`
`316`	`312`	`if (attributeList.Count > 0)`
`@@ -335,20 +331,18 @@ private static XElement GetXElementFromManifestPackageTypes(XNamespace ns, IEnum`
`335`	`331`
`336`	`332`	`private static XElement GetXElementFromManifestPackageType(XNamespace ns, PackageType packageType)`
`337`	`333`	`{`
`338`		`- var attributes = new List<XAttribute>();`
	`334`	`+ var attributes = new List<XAttribute?>();`
`339`	`335`
`340`	`336`	`attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Name, packageType.Name));`
`341`	`337`	`if (packageType.Version != PackageType.EmptyVersion)`
`342`	`338`	`{`
`343`	`339`	`attributes.Add(GetXAttributeFromNameAndValue(NuspecUtility.Version, packageType.Version));`
`344`	`340`	`}`
`345`	`341`
`346`		`- attributes = attributes.Where(xAtt => xAtt != null).ToList();`
`347`		`-`
`348`		`- return new XElement(ns + NuspecUtility.PackageType, attributes);`
	`342`	`+ return new XElement(ns + NuspecUtility.PackageType, attributes.Where(xAtt => xAtt != null));`
`349`	`343`	`}`
`350`	`344`
`351`		`- private static XAttribute GetXAttributeFromNameAndValue(string name, object value)`
	`345`	`+ private static XAttribute? GetXAttributeFromNameAndValue(string name, object? value)`
`352`	`346`	`{`
`353`	`347`	`if (name == null \|\| value == null)`
`354`	`348`	`{`
`@@ -358,7 +352,7 @@ private static XAttribute GetXAttributeFromNameAndValue(string name, object valu`
`358`	`352`	`return new XAttribute(name, value);`
`359`	`353`	`}`
`360`	`354`
`361`		`- private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T value)`
	`355`	`+ private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T? value)`
`362`	`356`	`where T : class`
`363`	`357`	`{`
`364`	`358`	`if (value != null)`
`@@ -367,7 +361,7 @@ private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, strin`
`367`	`361`	`}`
`368`	`362`	`}`
`369`	`363`
`370`		`- private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T value, Func<T, object> process)`
	`364`	`+ private static void AddElementIfNotNull<T>(XElement parent, XNamespace ns, string name, T? value, Func<T, object> process)`
`371`	`365`	`where T : class`
`372`	`366`	`{`
`373`	`367`	`if (value != null)`