Fix analyzer DLL import settings before Unity refresh

src/NuGetForUnity.Cli/Program.cs

@@ -4,7 +4,6 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
-using System.Text;
 using NugetForUnity;
 using NugetForUnity.Configuration;
 using NugetForUnity.Helper;
@@ -81,7 +80,6 @@ private static void FixRoslynAnalyzerImportSettings()
                 return;
             }
 
-            UTF8Encoding? utf8NoBom = null;
             foreach (var packageDirectoryPath in Directory.EnumerateDirectories(ConfigurationManager.NugetConfigFile.RepositoryPath))
             {
                 var analyzersDirectoryPath = Path.Combine(packageDirectoryPath, "analyzers");
@@ -92,39 +90,7 @@ private static void FixRoslynAnalyzerImportSettings()
 
                 foreach (var analyzerDllPath in Directory.EnumerateFiles(analyzersDirectoryPath, "*.dll", SearchOption.AllDirectories))
                 {
-                    var analyzerDllMetaPath = $"{analyzerDllPath}.meta";
-                    if (File.Exists(analyzerDllMetaPath))
-                    {
-                        continue;
-                    }
-
-                    var isSupportedRoslynAnalyzer = AnalyzerHelper.ShouldEnableRoslynAnalyzer(analyzerDllPath);
-                    var labelsForAsset = isSupportedRoslynAnalyzer ?
-                        """
-                        labels:
-                        - RoslynAnalyzer
-                        """ :
-                        "labels: []";
-                    utf8NoBom ??= new UTF8Encoding(false);
-                    File.WriteAllText(
-                        analyzerDllMetaPath,
-                        $"""
-                         fileFormatVersion: 2
-                         guid: {Guid.NewGuid():N}
-                         {labelsForAsset}
-                         PluginImporter:
-                           serializedVersion: 2
-                           platformData:
-                           - first:
-                               : Any
-                             second:
-                               enabled: 0
-                           - first:
-                               Any:
-                             second:
-                               enabled: 0
-                         """,
-                        utf8NoBom);
+                    AnalyzerHelper.WriteInitialRoslynAnalyzerImportSettings(analyzerDllPath);
                 }
             }
         }

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

@@ -111,11 +111,22 @@ public void InstallRoslynAnalyzerTest([Values] InstallMode installMode)
         var analyzer = new NugetPackageIdentifier("ErrorProne.NET.CoreAnalyzers", "0.1.2") { IsManuallyInstalled = true };
 
         // install the package
-        NugetPackageInstaller.InstallIdentifier(analyzer);
+        NugetPackageInstaller.InstallIdentifier(analyzer, false);
         try
         {
-            AssetDatabase.Refresh();
             var path = $"Assets/Packages/{analyzer.Id}.{analyzer.Version}/analyzers/dotnet/cs/ErrorProne.NET.Core.dll";
+            var analyzerDllPath = Path.Combine(
+                ConfigurationManager.NugetConfigFile.RepositoryPath,
+                $"{analyzer.Id}.{analyzer.Version}",
+                "analyzers",
+                "dotnet",
+                "cs",
+                "ErrorProne.NET.Core.dll");
+            var analyzerMetaPath = $"{analyzerDllPath}.meta";
+            Assert.That(analyzerMetaPath, Does.Exist.IgnoreDirectories, "Expected analyzer import settings before AssetDatabase.Refresh");
+            Assert.That(File.ReadAllText(analyzerMetaPath), Does.Contain("- RoslynAnalyzer"));
+
+            AssetDatabase.Refresh();
             var meta = (PluginImporter)AssetImporter.GetAtPath(path);
 
 #if UNITY_2022_3_OR_NEWER

src/NuGetForUnity/Editor/Helper/AnalyzerHelper.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Linq;
+using System.Text;
 using JetBrains.Annotations;
 using NugetForUnity.Models;
 
@@ -16,6 +17,11 @@ internal static class AnalyzerHelper
         /// </summary>
         private const string AnalyzersFolderName = "analyzers";
 
+        /// <summary>
+        ///     Used to let unity know an asset is a Roslyn-Analyzer.
+        /// </summary>
+        private const string RoslynAnalyzerLabel = "RoslynAnalyzer";
+
         /// <summary>
         ///     Name of the root folder containing dotnet analyzers.
         /// </summary>
@@ -53,6 +59,11 @@ public static bool ShouldEnableRoslynAnalyzer(string path)
                     .Where(version => version != null && version.CompareTo(maxSupportedRoslynVersion) <= 0)
                     .ToArray();
 
+                if (allEnabledRoslynVersions.Length == 0)
+                {
+                    return false;
+                }
+
                 // If most recent valid analyzers exist elsewhere, don't add label `RoslynAnalyzer`
                 var maxMatchingVersion = allEnabledRoslynVersions.Max();
                 if (!allEnabledRoslynVersions.Contains(assetRoslynVersion) || assetRoslynVersion < maxMatchingVersion)
@@ -64,6 +75,55 @@ public static bool ShouldEnableRoslynAnalyzer(string path)
             return true;
         }
 
+        /// <summary>
+        ///     Writes initial Unity import settings for a Roslyn analyzer DLL before Unity imports it for the first time.
+        /// </summary>
+        /// <param name="analyzerDllPath">The path to the analyzer DLL.</param>
+        public static void WriteInitialRoslynAnalyzerImportSettings([NotNull] string analyzerDllPath)
+        {
+            var analyzerDllMetaPath = $"{analyzerDllPath}.meta";
+            if (File.Exists(analyzerDllMetaPath))
+            {
+                return;
+            }
+
+            var labelsForAsset = ShouldEnableRoslynAnalyzer(analyzerDllPath) ?
+                $"labels:{Environment.NewLine}- {RoslynAnalyzerLabel}{Environment.NewLine}" :
+                $"labels: []{Environment.NewLine}";
+
+            File.WriteAllText(
+                analyzerDllMetaPath,
+                "fileFormatVersion: 2" + Environment.NewLine +
+                $"guid: {Guid.NewGuid():N}" + Environment.NewLine +
+                labelsForAsset +
+                "PluginImporter:" + Environment.NewLine +
+                "  externalObjects: {}" + Environment.NewLine +
+                "  serializedVersion: 2" + Environment.NewLine +
+                "  iconMap: {}" + Environment.NewLine +
+                "  executionOrder: {}" + Environment.NewLine +
+                "  defineConstraints: []" + Environment.NewLine +
+                "  isPreloaded: 0" + Environment.NewLine +
+                "  isOverridable: 0" + Environment.NewLine +
+                "  isExplicitlyReferenced: 0" + Environment.NewLine +
+                "  validateReferences: 1" + Environment.NewLine +
+                "  platformData:" + Environment.NewLine +
+                "  - first:" + Environment.NewLine +
+                "      Any: " + Environment.NewLine +
+                "    second:" + Environment.NewLine +
+                "      enabled: 0" + Environment.NewLine +
+                "      settings: {}" + Environment.NewLine +
+                "  - first:" + Environment.NewLine +
+                "      Editor: Editor" + Environment.NewLine +
+                "    second:" + Environment.NewLine +
+                "      enabled: 0" + Environment.NewLine +
+                "      settings:" + Environment.NewLine +
+                "        DefaultValueInitialized: true" + Environment.NewLine +
+                "  userData: " + Environment.NewLine +
+                "  assetBundleName: " + Environment.NewLine +
+                "  assetBundleVariant: " + Environment.NewLine,
+                new UTF8Encoding(false));
+        }
+
         [CanBeNull]
         private static NugetPackageVersion GetRoslynVersionNumberFromAnalyzerPath(string analyzerAssetPath)
         {

src/NuGetForUnity/Editor/NugetPackageInstaller.cs

@@ -5,6 +5,7 @@
 using System.Linq;
 using JetBrains.Annotations;
 using NugetForUnity.Configuration;
+using NugetForUnity.Helper;
 using NugetForUnity.Models;
 using NugetForUnity.PluginSupport;
 using UnityEditor;
@@ -219,6 +220,7 @@ private static PackageInstallOperationResult Install(
                         var libs = new Dictionary<string, List<ZipArchiveEntry>>();
                         var csFiles = new Dictionary<string, List<ZipArchiveEntry>>();
                         var anyFiles = new Dictionary<string, List<ZipArchiveEntry>>();
+                        var extractedAnalyzerDllPaths = new List<string>();
 
                         foreach (var entry in zip.Entries)
                         {
@@ -292,6 +294,13 @@ private static PackageInstallOperationResult Install(
 
                             var extractedFilePath = PackageContentManager.ExtractPackageEntry(entry, baseDirectory);
 
+                            if (extractedFilePath != null &&
+                                entryFullName.StartsWith("analyzers/", StringComparison.Ordinal) &&
+                                entryFullName.EndsWith(".dll", StringComparison.OrdinalIgnoreCase))
+                            {
+                                extractedAnalyzerDllPaths.Add(extractedFilePath);
+                            }
+
                             if (extractedFilePath != null &&
                                 (entryFullName.StartsWith("runtimes/", StringComparison.Ordinal) || entryFullName.Contains("/runtimes/")) &&
                                 RuntimePluginFileExtentions.Any(extension => entryFullName.EndsWith(extension, StringComparison.OrdinalIgnoreCase)))
@@ -336,6 +345,11 @@ private static PackageInstallOperationResult Install(
                         {
                             TryExtractBestFrameworkSources(anyFiles, baseDirectory, package, packageConfig);
                         }
+
+                        foreach (var analyzerDllPath in extractedAnalyzerDllPaths)
+                        {
+                            AnalyzerHelper.WriteInitialRoslynAnalyzerImportSettings(analyzerDllPath);
+                        }
                     }
                 }
                 else