Avoid unzipping .nupkg every time we need to read from .nuspec by saving .nuspec inside the package folder instead of .nupkg

src/NuGetForUnity.Tests/Assets/Tests/Editor/NuGetTests.cs

@@ -317,21 +317,25 @@ public void InstallAndSearchLocalPackageSource([Values] bool hierarchical)
             // get the package file by installing it
             NugetPackageInstaller.InstallIdentifier(package);
             Assert.IsTrue(InstalledPackagesManager.IsInstalled(package), "The package was NOT installed: {0} {1}", package.Id, package.Version);
-            var packageFilePath = Path.Combine(
+            var nuspecFilePath = Path.Combine(
                 ConfigurationManager.NugetConfigFile.RepositoryPath,
                 $"{package.Id}.{package.Version}",
-                package.PackageFileName);
-            Assert.That(packageFilePath, Does.Exist.IgnoreDirectories);
+                package.SpecificationFileName);
+            Assert.That(nuspecFilePath, Does.Exist.IgnoreDirectories);
+
+            var nupkgFileName = $"{package.Id}.{package.Version}.nupkg";
+            var nupkgFilePath = Path.Combine(PackageCacheManager.CacheOutputDirectory, nupkgFileName);
+            Assert.That(nupkgFilePath, Does.Exist.IgnoreDirectories);
 
             // Hierarchical folder structures are supported in NuGet 3.3+.
             // └─<packageID>
             //   └─<version>
-            //     └─<packageID>.<version>.nupkg
+            //     └─<packageID>.<packageVersion>.nupkg
             var targetDirectory = Path.Combine(
                 tempDirectoryPath,
                 hierarchical ? $"{package.Id}{Path.DirectorySeparatorChar}{package.Version}" : string.Empty);
             Directory.CreateDirectory(targetDirectory);
-            File.Copy(packageFilePath, Path.Combine(targetDirectory, Path.GetFileName(packageFilePath)));
+            File.Copy(nupkgFilePath, Path.Combine(targetDirectory, nupkgFileName));
             NugetPackageUninstaller.UninstallAll(InstalledPackagesManager.InstalledPackages.ToList());
             Assert.IsFalse(InstalledPackagesManager.IsInstalled(package), "The package is STILL installed: {0} {1}", package.Id, package.Version);
 

src/NuGetForUnity/Editor/InstalledPackagesManager.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.IO.Compression;
 using System.Linq;
 using NugetForUnity.Configuration;
 using NugetForUnity.Helper;
@@ -170,14 +171,33 @@ internal static void UpdateInstalledPackages()
             var stopwatch = Stopwatch.StartNew();
             var manuallyInstalledPackagesNumber = 0;
 
-            // a package that was installed via NuGet will have the .nupkg it came from inside the folder
+            // a package that was installed via a old version of NuGetForUnity will have the .nupkg it came from inside the folder,
+            // as we updated the behavior to only keep the .nuspec. So we need to extract the .nuspec from the .nupkg
             var nupkgFiles = Directory.GetFiles(ConfigurationManager.NugetConfigFile.RepositoryPath, "*.nupkg", SearchOption.AllDirectories);
             foreach (var nupkgFile in nupkgFiles)
             {
-                var package = NugetPackageLocal.FromNupkgFile(
-                    nupkgFile,
-                    new NugetPackageSourceLocal("Nupkg file from Project", Path.GetDirectoryName(nupkgFile)));
-                AddPackageToInstalledInternal(package, ref manuallyInstalledPackagesNumber);
+                using (var zip = ZipFile.OpenRead(nupkgFile))
+                {
+                    foreach (var entry in zip.Entries)
+                    {
+                        var entryFullName = entry.FullName;
+
+                        // extract only .nuspec and .nuspec.meta files
+                        if (entryFullName.EndsWith(".nuspec.meta", StringComparison.Ordinal) ||
+                            entryFullName.EndsWith(".nuspec", StringComparison.Ordinal))
+                        {
+                            PackageContentManager.ExtractPackageEntry(entry, Path.GetDirectoryName(nupkgFile));
+                        }
+                    }
+                }
+
+                // delete .nupkg and its .meta file to sync compatibility
+                File.Delete(nupkgFile);
+                var metaFile = $"{nupkgFile}.meta";
+                if (File.Exists(metaFile))
+                {
+                    File.Delete($"{nupkgFile}.meta");
+                }
             }
 
             // if the source code & assets for a package are pulled directly into the project (ex: via a symlink/junction) it should have a .nuspec defining the package
@@ -226,16 +246,16 @@ internal static bool RemoveUnnecessaryPackages()
                     continue;
                 }
 
-                var pkgPath = Path.Combine(folder, $"{folderName}.nupkg");
-                if (!File.Exists(pkgPath))
+                var nuspecPath = Directory.GetFiles(folder, "*.nuspec").FirstOrDefault();
+                if (!File.Exists(nuspecPath))
                 {
-                    // ignore folder not containing a nuget-package
+                    // ignore folder not containing a nuspec file
                     continue;
                 }
 
-                var package = NugetPackageLocal.FromNupkgFile(
-                    pkgPath,
-                    new NugetPackageSourceLocal("Nupkg file already installed", Path.GetDirectoryName(pkgPath)));
+                var package = NugetPackageLocal.FromNuspecFile(
+                    nuspecPath,
+                    new NugetPackageSourceLocal("Nuspec file already installed", Path.GetDirectoryName(nuspecPath)));
 
                 var installed = PackagesConfigFile.Packages.Any(packageId => packageId.Equals(package));
 

src/NuGetForUnity/Editor/Models/NugetPackageIdentifier.cs

@@ -62,7 +62,7 @@ public string Version
         public string PackageFileName => $"{Id}.{Version}.nupkg";
 
         /// <inheritdoc />
-        public string SpecificationFileName => $"{Id}.{Version}.nuspec";
+        public string SpecificationFileName => $"{Id}.nuspec";
 
         /// <inheritdoc />
         public bool IsPrerelease => PackageVersion.IsPrerelease;

src/NuGetForUnity/Editor/Models/NugetPackageLocal.cs

@@ -57,5 +57,18 @@ public static NugetPackageLocal FromNupkgFile(string nupkgFilePath, NugetPackage
             package.DownloadUrl = nupkgFilePath;
             return package;
         }
+
+        /// <summary>
+        ///     Loads a <see cref="NugetPackageLocal" /> from the .nuspec file at the given file-path.
+        /// </summary>
+        /// <param name="nuspecFilePath">The file-path to the .nuspec file to load.</param>
+        /// <param name="packageSource">The source this package was downloaded with / provided by.</param>
+        /// <returns>The <see cref="NugetPackageLocal" /> loaded from the .nuspec file.</returns>
+        public static NugetPackageLocal FromNuspecFile(string nuspecFilePath, NugetPackageSourceLocal packageSource)
+        {
+            var package = FromNuspec(NuspecFile.Load(nuspecFilePath), packageSource);
+            package.DownloadUrl = nuspecFilePath;
+            return package;
+        }
     }
 }

src/NuGetForUnity/Editor/Models/NugetPackageV2.cs

@@ -41,18 +41,5 @@ public static NugetPackageV2 FromNuspec(NuspecFile nuspec, NugetPackageSourceV2
             FillFromNuspec(nuspec, package);
             return package;
         }
-
-        /// <summary>
-        ///     Loads a <see cref="NugetPackageV2" /> from the .nupkg file at the given file-path.
-        /// </summary>
-        /// <param name="nupkgFilePath">The file-path to the .nupkg file to load.</param>
-        /// <param name="packageSource">The source this package was downloaded with / provided by.</param>
-        /// <returns>The <see cref="NugetPackageV2" /> loaded from the .nupkg file.</returns>
-        public static NugetPackageV2 FromNupkgFile(string nupkgFilePath, NugetPackageSourceV2 packageSource)
-        {
-            var package = FromNuspec(NuspecFile.FromNupkgFile(nupkgFilePath), packageSource);
-            package.DownloadUrl = nupkgFilePath;
-            return package;
-        }
     }
 }

src/NuGetForUnity/Editor/NugetPackageInstaller.cs

@@ -176,7 +176,7 @@ private static bool Install(INugetPackage package, bool refreshAssets, bool inst
                         foreach (var entry in zip.Entries)
                         {
                             var entryFullName = entry.FullName;
-                            if (PackageContentManager.ShouldSkipUnpackingOnPath(entryFullName, package.Id))
+                            if (PackageContentManager.ShouldSkipUnpackingOnPath(entryFullName))
                             {
                                 continue;
                             }
@@ -227,9 +227,6 @@ private static bool Install(INugetPackage package, bool refreshAssets, bool inst
                             Debug.LogWarningFormat("Couldn't find a library folder with a supported target-framework for the package {0}", package);
                         }
                     }
-
-                    // copy the .nupkg inside the Unity project
-                    File.Copy(cachedPackagePath, Path.Combine(baseDirectory, package.PackageFileName), true);
                 }
                 else
                 {

src/NuGetForUnity/Editor/NuspecFile.cs

@@ -139,7 +139,7 @@ public static NuspecFile FromNupkgFile(string nupkgFilePath)
         {
             var nuspec = new NuspecFile();
 
-            if (File.Exists(nupkgFilePath))
+            try
             {
                 // get the .nuspec file from inside the .nupkg
                 using (var zip = ZipFile.OpenRead(nupkgFilePath))
@@ -152,8 +152,9 @@ public static NuspecFile FromNupkgFile(string nupkgFilePath)
                     }
                 }
             }
-            else
+            catch (Exception e)
             {
+                Debug.LogException(e);
                 Debug.LogErrorFormat("Package could not be read: {0}", nupkgFilePath);
                 nuspec.Description = $"COULD NOT LOAD {nupkgFilePath}";
             }

src/NuGetForUnity/Editor/PackageContentManager.cs

@@ -108,14 +108,8 @@ internal static void CleanInstallationDirectory(INugetPackageIdentifier package)
         /// </param>
         /// <param name="packageId">The id of the package that is extracted.</param>
         /// <returns>True if the file can be skipped, is not needed.</returns>
-        internal static bool ShouldSkipUnpackingOnPath(string path, string packageId)
+        internal static bool ShouldSkipUnpackingOnPath(string path)
         {
-            // skip a remnant .meta file that may exist from packages created by Unity
-            if (path.EndsWith($"{packageId}.nuspec.meta", StringComparison.Ordinal))
-            {
-                return true;
-            }
-
             // skip directories & files that NuGet normally deletes
             if (path.StartsWith("_rels/", StringComparison.Ordinal) || path.Contains("/_rels/"))
             {
@@ -127,11 +121,6 @@ internal static bool ShouldSkipUnpackingOnPath(string path, string packageId)
                 return true;
             }
 
-            if (path.EndsWith($"{packageId}.nuspec", StringComparison.Ordinal))
-            {
-                return true;
-            }
-
             if (path.EndsWith("[Content_Types].xml", StringComparison.Ordinal))
             {
                 return true;