Enabling nullability in NuGet.Packaging - Package Reading APIs, PackageArchiveReader and all its interfaces (#7210)

Author: nkolev92

src/NuGet.Core/NuGet.Packaging/Core/ExtractPackageFileDelegate.cs

@@ -12,5 +12,5 @@ namespace NuGet.Packaging.Core
     /// <param name="targetPath">The path to write to.</param>
     /// <param name="fileStream">The file <see cref="Stream"/>.</param>
     /// <returns>The file name if the file was written; otherwise <see langword="null" />.</returns>
-    public delegate string ExtractPackageFileDelegate(string sourceFile, string targetPath, Stream fileStream);
+    public delegate string? ExtractPackageFileDelegate(string sourceFile, string targetPath, Stream fileStream);
 }

src/NuGet.Core/NuGet.Packaging/Core/INuspecCoreReader.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.Collections.Generic;
 using NuGet.Versioning;
 
@@ -17,18 +15,22 @@ public interface INuspecCoreReader
         /// <summary>
         /// Package Id
         /// </summary>
-        /// <returns></returns>
+        /// <remarks>NU_NULL_INC :This method is annotated as not nullable intentionally.
+        /// The null return is possible only with malformed nuspecs and practically illegal in cases dealing with an actual package.</remarks>
+        /// <returns>package id</returns>
         string GetId();
 
         /// <summary>
         /// Package Version
         /// </summary>
+        /// <remarks>NU_NULL_INC :This method is annotated as not nullable intentionally.
+        /// The null return is possible only with malformed nuspecs and practically illegal in cases dealing with an actual package.</remarks>
         NuGetVersion GetVersion();
 
         /// <summary>
         /// Minimum client version needed to consume the package.
         /// </summary>
-        NuGetVersion GetMinClientVersion();
+        NuGetVersion? GetMinClientVersion();
 
         /// <summary>
         /// Gets zero or more package types from the .nuspec.

src/NuGet.Core/NuGet.Packaging/Core/NuspecCoreReader.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.Collections.Generic;
 using System.IO;
 using System.Xml.Linq;
@@ -50,7 +48,7 @@ public virtual IEnumerable<PackageDependency> GetDependencies()
                     range = VersionRange.Parse(versionNode.Value);
                 }
 
-                yield return new PackageDependency(node.Attribute(XName.Get(Id)).Value, range);
+                yield return new PackageDependency(node.Attribute(XName.Get(Id))!.Value, range);
             }
 
             yield break;

src/NuGet.Core/NuGet.Packaging/Core/NuspecCoreReaderBase.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.Globalization;
@@ -20,8 +18,8 @@ namespace NuGet.Packaging.Core
     public abstract class NuspecCoreReaderBase : INuspecCoreReader
     {
         private readonly XDocument _xml;
-        private XElement _metadataNode;
-        private Dictionary<string, string> _metadataValues;
+        private XElement? _metadataNode;
+        private Dictionary<string, string>? _metadataValues;
 
         protected const string Metadata = "metadata";
         protected const string Id = "id";
@@ -79,25 +77,29 @@ public NuspecCoreReaderBase(XDocument xml)
         /// <summary>
         /// Id of the package
         /// </summary>
+        /// <remarks>NU_NULL_INC :This method is annotated as not nullable intentionally.
+        /// The null return is possible only with malformed nuspecs and practically illegal in cases dealing with an actual package.</remarks>
         public virtual string GetId()
         {
             var node = MetadataNode.Elements(XName.Get(Id, MetadataNode.GetDefaultNamespace().NamespaceName)).FirstOrDefault();
-            return node == null ? null : node.Value;
+            return node == null ? null! : node.Value;
         }
 
         /// <summary>
         /// Version of the package
         /// </summary>
+        /// <remarks>NU_NULL_INC :This method is annotated as not nullable intentionally.
+        /// The null return is possible only with malformed nuspecs and practically illegal in cases dealing with an actual package.</remarks>
         public virtual NuGetVersion GetVersion()
         {
             var node = MetadataNode.Elements(XName.Get(Version, MetadataNode.GetDefaultNamespace().NamespaceName)).FirstOrDefault();
-            return node == null ? null : NuGetVersion.Parse(node.Value);
+            return node == null ? null! : NuGetVersion.Parse(node.Value);
         }
 
         /// <summary>
         /// The minimum client version this package supports.
         /// </summary>
-        public virtual NuGetVersion GetMinClientVersion()
+        public virtual NuGetVersion? GetMinClientVersion()
         {
             var node = MetadataNode.Attribute(XName.Get(MinClientVersion));
             return node == null ? null : NuGetVersion.Parse(node.Value);
@@ -144,7 +146,7 @@ public virtual IEnumerable<KeyValuePair<string, string>> GetMetadata()
         /// </summary>
         public virtual string GetMetadataValue(string name)
         {
-            string metadataValue;
+            string? metadataValue;
             MetadataValues.TryGetValue(name, out metadataValue);
             return metadataValue ?? string.Empty;
         }
@@ -183,7 +185,7 @@ protected XElement MetadataNode
                 if (_metadataNode == null)
                 {
                     // find the metadata node regardless of the NS, some legacy packages have the NS here instead of on package
-                    _metadataNode = _xml.Root.Elements().FirstOrDefault(e => StringComparer.Ordinal.Equals(e.Name.LocalName, Metadata));
+                    _metadataNode = _xml.Root!.Elements().FirstOrDefault(e => StringComparer.Ordinal.Equals(e.Name.LocalName, Metadata));
 
                     if (_metadataNode == null)
                     {

src/NuGet.Core/NuGet.Packaging/Definitions/IPackageDownloader.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.Threading;
 using System.Threading.Tasks;
@@ -78,6 +76,6 @@ public interface IPackageDownloader : IDisposable
         /// Sets a throttle for package downloads.
         /// </summary>
         /// <param name="throttle">A throttle.  Can be <see langword="null" />.</param>
-        void SetThrottle(SemaphoreSlim throttle);
+        void SetThrottle(SemaphoreSlim? throttle);
     }
 }

src/NuGet.Core/NuGet.Packaging/NupkgMetadata/NupkgMetadataFile.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 NuGet.Shared;
 
@@ -12,11 +10,11 @@ public class NupkgMetadataFile : IEquatable<NupkgMetadataFile>
     {
         public int Version { get; set; } = NupkgMetadataFileFormat.Version;
 
-        public string ContentHash { get; set; }
+        public string? ContentHash { get; set; }
 
-        public string Source { get; set; }
+        public string? Source { get; set; }
 
-        public bool Equals(NupkgMetadataFile other)
+        public bool Equals(NupkgMetadataFile? other)
         {
             if (other == null)
             {
@@ -33,7 +31,7 @@ public bool Equals(NupkgMetadataFile other)
                 StringComparer.Ordinal.Equals(Source, other.Source);
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             return Equals(obj as NupkgMetadataFile);
         }

src/NuGet.Core/NuGet.Packaging/NupkgMetadata/NupkgMetadataFileFormat.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.IO;
@@ -46,7 +44,7 @@ public static NupkgMetadataFile Read(Stream stream, ILogger log, string path)
 
             try
             {
-                NupkgMetadataFile nupkgMetadata = JsonSerializer.Deserialize<NupkgMetadataFile>(stream, JsonContext.NupkgMetadataFile);
+                NupkgMetadataFile? nupkgMetadata = JsonSerializer.Deserialize<NupkgMetadataFile>(stream, JsonContext.NupkgMetadataFile);
                 if (nupkgMetadata == null)
                 {
                     throw new InvalidDataException();
@@ -76,7 +74,7 @@ public static void Write(string filePath, NupkgMetadataFile hashFile)
         {
             // Create the directory if it does not exist
             var fileInfo = new FileInfo(filePath);
-            fileInfo.Directory.Create();
+            fileInfo.Directory!.Create();
 
             using (var stream = new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None))
             {