Fix build warnings (#4458)

* Fix low-risk build warnings

* Fix IDE2000 build warnings

* Fix CA1852 build warnings

* Fix CS4014 build warnings

* Fix safe CA1822 build warning

* Fix IDE0031 build warnings

* Fix IDE0051 build warnings

* Fix CA1830 and CA1835 build warnings

* Fix CS0067 build warnings

* Fix CA2201 build warnings

* Fix safe nullability build warnings

* Fix remaining CA1416 build warnings

* Finalize build warning cleanup

* Fix verified final build warnings

* Fix generated CS4014 build warnings

* Fix CI meta-test for AutoUpdater serialization

Author: mamoreau-devolutions

src/Directory.Build.props

@@ -52,5 +52,6 @@
     <PropertyGroup>
         <LangVersion>latest</LangVersion>
         <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
+        <NoWarn>$(NoWarn);EnableGenerateDocumentationFile</NoWarn>
     </PropertyGroup>
 </Project>

src/UniGetUI.Core.Classes.Tests/TaskRecyclerTests.cs

@@ -1,3 +1,5 @@
+using System.Diagnostics.CodeAnalysis;
+
 namespace UniGetUI.Core.Classes.Tests;
 
 public class TaskRecyclerTests
@@ -8,16 +10,18 @@ private int MySlowMethod1()
         return new Random().Next();
     }
 
-    private class TestClass
+    private sealed class TestClass
     {
         public TestClass() {}
 
+        [SuppressMessage("Performance", "CA1822:Mark members as static", Justification = "Instance methods are required to validate TaskRecycler instance-bound delegate behavior.")]
         public string SlowMethod2()
         {
             Thread.Sleep(1000);
             return new Random().Next().ToString();
         }
 
+        [SuppressMessage("Performance", "CA1822:Mark members as static", Justification = "Instance methods are required to validate TaskRecycler instance-bound delegate behavior.")]
         public string SlowMethod3()
         {
             Thread.Sleep(1000);

src/UniGetUI.Core.Classes/TaskRecycler.cs

@@ -93,7 +93,6 @@ public static void RemoveFromCache(Func<ReturnT> method)
 
     // ---------------------------------------------------------------------------------------------------------------
 
-
     /// <summary>
     /// Handles running the task if no such task was found on cache, and returning the cached task if it was found.
     /// </summary>

src/UniGetUI.Core.Data/CoreCredentialStore.cs

@@ -93,6 +93,7 @@ public static void DeleteSecret(string resourceName, string userName)
         }
     }
 
+#if !WINDOWS
     private static string GetStorageDirectory()
         => Path.Join(CoreData.UniGetUIDataDirectory, "SecureStorage");
 
@@ -104,4 +105,5 @@ private static string GetStableFileName(string resourceName, string userName)
         byte[] hash = SHA256.HashData(Encoding.UTF8.GetBytes($"{resourceName}\n{userName}"));
         return Convert.ToHexString(hash) + ".secret";
     }
+#endif
 }

src/UniGetUI.Core.Data/CoreData.cs

@@ -59,7 +59,7 @@ public static string UniGetUIDataDirectory
                     }
                 } else if (IS_PORTABLE is true)
                 {
-                    return PORTABLE_PATH ?? throw new Exception("This shouldn't be possible");
+                    return PORTABLE_PATH ?? throw new InvalidOperationException("This shouldn't be possible");
                 }
 
                 string old_path = Path.Join(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".wingetui");

src/UniGetUI.Core.IconStore/IconDatabase.cs

@@ -19,7 +19,6 @@ public struct IconCount
             public IconCount() { }
         }
 
-
         private static IconDatabase? __instance;
         public static IconDatabase Instance
         {
@@ -57,7 +56,6 @@ public async Task LoadIconAndScreenshotsDatabaseAsync()
 
                 Logger.ImportantInfo("Downloaded new icons and screenshots successfully!");
 
-
                 if (!File.Exists(IconsAndScreenshotsFile))
                 {
                     Logger.Error("Icon Database file not found");
@@ -74,7 +72,6 @@ public async Task LoadIconAndScreenshotsDatabaseAsync()
             await LoadFromCacheAsync();
         }
 
-
         public async Task LoadFromCacheAsync()
         {
             try

src/UniGetUI.Core.SecureSettings/SecureSettings.cs

@@ -34,7 +34,6 @@ public static string ResolveKey(K key)
         };
     }
 
-
     private static readonly Dictionary<string, bool> _cache = new();
 
     public static class Args

src/UniGetUI.Core.Settings.Tests/SettingsTest.cs

@@ -18,7 +18,7 @@ public sealed class SerializableTest
         public SerializableTestSub sub { get; set; }
     }
 
-    public class SettingsTest
+    public class SettingsTest : IDisposable
     {
         private readonly string _testRoot;
 
@@ -50,7 +50,6 @@ public void Dispose()
         private string GetNewSettingPath(string fileName) => Path.Combine(_newConfigurationDirectory, fileName);
         private string GetOldSettingsPath(string fileName) => Path.Combine(_oldConfigurationDirectory, fileName);
 
-
         [Fact]
         public void TestSettingsSaveToNewDirectory()
         {
@@ -175,7 +174,9 @@ public void TestListSettings(string SettingName, string[] ls1Array, int[] ls2Arr
             Assert.Equal("this is now a test case", Settings.GetListItem<string>(SettingName, 3));
             Assert.Null(Settings.GetListItem<string>(SettingName, 4));
 
-            Assert.Equal(Settings.GetListItem<string>(SettingName, 0), JsonSerializer.Deserialize<List<string>>(File.ReadAllText(Path.Join(CoreData.UniGetUIUserConfigurationDirectory, $"{SettingName}.json")), Settings.SerializationOptions)[0]);
+            List<string>? persistedList = JsonSerializer.Deserialize<List<string>>(File.ReadAllText(Path.Join(CoreData.UniGetUIUserConfigurationDirectory, $"{SettingName}.json")), Settings.SerializationOptions);
+            Assert.NotNull(persistedList);
+            Assert.Equal(Settings.GetListItem<string>(SettingName, 0), persistedList[0]);
             Settings.ClearList(SettingName);
             Assert.Empty(Settings.GetList<object>(SettingName) ?? ["this shouldn't be null; something's wrong"]);
 

src/UniGetUI.Core.Settings/SettingsEngine_Dictionaries.cs

@@ -10,7 +10,7 @@ public static partial class Settings
         private static readonly ConcurrentDictionary<K, Dictionary<object, object?>> _dictionarySettings = new();
 
         // Returns an empty dictionary if the setting doesn't exist and null if the types are invalid
-        private static Dictionary<KeyT, ValueT?> _getDictionary<KeyT, ValueT>(K key)
+        private static Dictionary<KeyT, ValueT?>? _getDictionary<KeyT, ValueT>(K key)
             where KeyT : notnull
          {
             string setting = ResolveKey(key);
@@ -73,7 +73,7 @@ public static partial class Settings
         }
 
         // Returns an empty dictionary if the setting doesn't exist and null if the types are invalid
-        public static IReadOnlyDictionary<KeyT, ValueT?> GetDictionary<KeyT, ValueT>(K settingsKey)
+        public static IReadOnlyDictionary<KeyT, ValueT?>? GetDictionary<KeyT, ValueT>(K settingsKey)
             where KeyT : notnull
         {
             return _getDictionary<KeyT, ValueT?>(settingsKey);

src/UniGetUI.Core.Tools/DWMThreadHelper.cs

@@ -144,7 +144,6 @@ private static void ChangeState(bool suspend, IntPtr expectedAdress, ref bool Is
             return;
         }
 
-
         if (suspend)
         {
             uint res = SuspendThread(hThread);