CmdPal: Null pattern matching based on is expression rather than overridable operators (#40972)

What the title says. 😄 

Rather than relying on the potentially overloaded `!=` or `==` operators
when checking for null, now we'll use the `is` expression (possibly
combined with the `not` operator) to ensure correct checking. Probably
overkill for many of these classes, but decided to err on the side of
consistency. Would matter more on classes that may be inherited or
extended.

Using `is` and `is not` will provide us a guarantee that no
user-overloaded equality operators (`==`/`!=`) is invoked when a
`expression is null` is evaluated.

In code form, changed all instances of:

```c#
something != null

something == null
```

to:

```c#
something is not null

something is null
```

The one exception was checking null on a `KeyChord`. `KeyChord` is a
struct which is never null so VS will raise an error when trying this
versus just providing a warning when using `keyChord != null`. In
reality, we shouldn't do this check because it can't ever be null. In
the case of a `KeyChord` it **would** be a `KeyChord` equivalent to:

```c#
KeyChord keyChord = new ()
{
    Modifiers = 0,
    Vkey = 0,
    ScanCode = 0
};
```

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/AllAppsPage.cs

@@ -2,16 +2,12 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using System.Numerics;
-using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using ManagedCommon;
-using Microsoft.CmdPal.Ext.Apps.Commands;
 using Microsoft.CmdPal.Ext.Apps.Programs;
 using Microsoft.CmdPal.Ext.Apps.Properties;
 using Microsoft.CmdPal.Ext.Apps.State;
@@ -145,7 +141,7 @@ public sealed partial class AllAppsPage : ListPage
         */
         var existingAppItem = allApps.FirstOrDefault(f => f.AppIdentifier == e.AppIdentifier);
 
-        if (existingAppItem != null)
+        if (existingAppItem is not null)
         {
             var appListItem = new AppListItem(existingAppItem, true, e.IsPinned);
 

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/AppCache.cs

@@ -4,7 +4,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.CmdPal.Ext.Apps.Programs;
@@ -66,7 +65,7 @@ public sealed partial class AppCache : IDisposable
 
     private void UpdateUWPIconPath(Theme theme)
     {
-        if (_packageRepository != null)
+        if (_packageRepository is not null)
         {
             foreach (UWPApplication app in _packageRepository)
             {

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/AppListItem.cs

@@ -72,7 +72,7 @@ internal sealed partial class AppListItem : ListItem
             try
             {
                 var stream = await ThumbnailHelper.GetThumbnail(_app.ExePath, true);
-                if (stream != null)
+                if (stream is not null)
                 {
                     heroImage = IconInfo.FromStream(stream);
                 }
@@ -106,7 +106,7 @@ internal sealed partial class AppListItem : ListItem
             try
             {
                 var stream = await ThumbnailHelper.GetThumbnail(_app.ExePath);
-                if (stream != null)
+                if (stream is not null)
                 {
                     var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                     icon = new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Programs/AppxPackageHelper.cs

@@ -6,9 +6,7 @@ using System;
 using System.Collections.Generic;
 using ManagedCommon;
 using Microsoft.CmdPal.Ext.Apps.Utils;
-using Microsoft.UI.Xaml.Controls;
 using Windows.Win32;
-using Windows.Win32.Foundation;
 using Windows.Win32.Storage.Packaging.Appx;
 using Windows.Win32.System.Com;
 
@@ -51,14 +49,14 @@ public static class AppxPackageHelper
                 {
                     result.Add((IntPtr)manifestApp);
                 }
-                else if (manifestApp != null)
+                else if (manifestApp is not null)
                 {
                     manifestApp->Release();
                 }
             }
             catch (Exception ex)
             {
-                if (manifestApp != null)
+                if (manifestApp is not null)
                 {
                     manifestApp->Release();
                 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Programs/PackageManagerWrapper.cs

@@ -22,11 +22,11 @@ public class PackageManagerWrapper : IPackageManager
     {
         var user = WindowsIdentity.GetCurrent().User;
 
-        if (user != null)
+        if (user is not null)
         {
             var pkgs = _packageManager.FindPackagesForUser(user.Value);
 
-            return pkgs.Select(PackageWrapper.GetWrapperFromPackage).Where(package => package != null);
+            return pkgs.Select(PackageWrapper.GetWrapperFromPackage).Where(package => package is not null);
         }
 
         return Enumerable.Empty<IPackage>();

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Programs/UWP.cs

@@ -11,9 +11,7 @@ using System.Threading.Tasks;
 using System.Xml.Linq;
 using ManagedCommon;
 using Microsoft.CmdPal.Ext.Apps.Utils;
-using Microsoft.CommandPalette.Extensions.Toolkit;
 using Windows.Win32;
-using Windows.Win32.Foundation;
 using Windows.Win32.Storage.Packaging.Appx;
 using Windows.Win32.System.Com;
 
@@ -99,7 +97,7 @@ public partial class UWP
     private static string[] XmlNamespaces(string path)
     {
         var z = XDocument.Load(path);
-        if (z.Root != null)
+        if (z.Root is not null)
         {
             var namespaces = z.Root.Attributes().
                 Where(a => a.IsNamespaceDeclaration).

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Programs/UWPApplication.cs

@@ -308,7 +308,7 @@ public class UWPApplication : IProgram
     private bool SetScaleIcons(string path, string colorscheme, bool highContrast = false)
     {
         var extension = Path.GetExtension(path);
-        if (extension != null)
+        if (extension is not null)
         {
             var end = path.Length - extension.Length;
             var prefix = path.Substring(0, end);
@@ -363,7 +363,7 @@ public class UWPApplication : IProgram
     private bool SetTargetSizeIcon(string path, string colorscheme, bool highContrast = false)
     {
         var extension = Path.GetExtension(path);
-        if (extension != null)
+        if (extension is not null)
         {
             var end = path.Length - extension.Length;
             var prefix = path.Substring(0, end);
@@ -576,7 +576,7 @@ public class UWPApplication : IProgram
 
             var group = new DrawingGroup();
             var converted = ColorConverter.ConvertFromString(currentBackgroundColor);
-            if (converted != null)
+            if (converted is not null)
             {
                 var color = (Color)converted;
                 var brush = new SolidColorBrush(color);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Programs/Win32Program.cs

@@ -170,7 +170,7 @@ public class Win32Program : IProgram
 
     public bool QueryEqualsNameForRunCommands(string query)
     {
-        if (query != null && AppType == ApplicationType.RunCommand)
+        if (query is not null && AppType == ApplicationType.RunCommand)
         {
             // Using OrdinalIgnoreCase since this is used internally
             if (!query.Equals(Name, StringComparison.OrdinalIgnoreCase) && !query.Equals(ExecutableName, StringComparison.OrdinalIgnoreCase))
@@ -667,7 +667,7 @@ public class Win32Program : IProgram
         var paths = new List<string>();
         using (var root = Registry.LocalMachine.OpenSubKey(appPaths))
         {
-            if (root != null)
+            if (root is not null)
             {
                 paths.AddRange(GetPathsFromRegistry(root));
             }
@@ -675,7 +675,7 @@ public class Win32Program : IProgram
 
         using (var root = Registry.CurrentUser.OpenSubKey(appPaths))
         {
-            if (root != null)
+            if (root is not null)
             {
                 paths.AddRange(GetPathsFromRegistry(root));
             }
@@ -700,7 +700,7 @@ public class Win32Program : IProgram
         {
             using (var key = root.OpenSubKey(subkey))
             {
-                if (key == null)
+                if (key is null)
                 {
                     return string.Empty;
                 }
@@ -742,13 +742,13 @@ public class Win32Program : IProgram
 
         public bool Equals(Win32Program? app1, Win32Program? app2)
         {
-            if (app1 == null && app2 == null)
+            if (app1 is null && app2 is null)
             {
                 return true;
             }
 
-            return app1 != null
-                    && app2 != null
+            return app1 is not null
+                    && app2 is not null
                     && (app1.Name?.ToUpperInvariant(), app1.ExecutableName?.ToUpperInvariant(), app1.FullPath?.ToUpperInvariant())
                     .Equals((app2.Name?.ToUpperInvariant(), app2.ExecutableName?.ToUpperInvariant(), app2.FullPath?.ToUpperInvariant()));
         }
@@ -908,7 +908,7 @@ public class Win32Program : IProgram
             Parallel.ForEach(paths, source =>
             {
                 var program = GetProgramFromPath(source);
-                if (program != null)
+                if (program is not null)
                 {
                     programsList.Add(program);
                 }
@@ -918,7 +918,7 @@ public class Win32Program : IProgram
             Parallel.ForEach(runCommandPaths, source =>
             {
                 var program = GetRunCommandProgramFromPath(source);
-                if (program != null)
+                if (program is not null)
                 {
                     runCommandProgramsList.Add(program);
                 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Storage/FileSystemWatcherWrapper.cs

@@ -19,7 +19,7 @@ public sealed partial class FileSystemWatcherWrapper : FileSystemWatcher, IFileS
         get => this.Filters;
         set
         {
-            if (value != null)
+            if (value is not null)
             {
                 foreach (var filter in value)
                 {

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Storage/Win32ProgramRepository.cs

@@ -10,7 +10,6 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Threading.Tasks;
 using ManagedCommon;
-using Microsoft.CmdPal.Ext.Apps.Programs;
 using Win32Program = Microsoft.CmdPal.Ext.Apps.Programs.Win32Program;
 
 namespace Microsoft.CmdPal.Ext.Apps.Storage;
@@ -53,7 +52,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
                 if (!string.IsNullOrEmpty(appPath))
                 {
                     Win32Program? app = Win32Program.GetAppFromPath(appPath);
-                    if (app != null)
+                    if (app is not null)
                     {
                         Add(app);
                         _isDirty = true;
@@ -137,7 +136,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
         }
 
         // To remove the old app which has been renamed and to add the new application.
-        if (oldApp != null)
+        if (oldApp is not null)
         {
             if (string.IsNullOrWhiteSpace(oldApp.Name) || string.IsNullOrWhiteSpace(oldApp.ExecutableName) || string.IsNullOrWhiteSpace(oldApp.FullPath))
             {
@@ -149,7 +148,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
             }
         }
 
-        if (newApp != null)
+        if (newApp is not null)
         {
             Add(newApp);
             _isDirty = true;
@@ -177,7 +176,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
             if (extension.Equals(LnkExtension, StringComparison.OrdinalIgnoreCase))
             {
                 app = GetAppWithSameLnkFilePath(path);
-                if (app == null)
+                if (app is null)
                 {
                     // Cancelled links won't have a resolved path.
                     app = GetAppWithSameNameAndExecutable(Path.GetFileNameWithoutExtension(path), Path.GetFileName(path));
@@ -197,7 +196,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
             Logger.LogError(ex.Message);
         }
 
-        if (app != null)
+        if (app is not null)
         {
             Remove(app);
             _isDirty = true;
@@ -244,7 +243,7 @@ internal sealed partial class Win32ProgramRepository : ListRepository<Programs.W
         if (!Path.GetExtension(path).Equals(UrlExtension, StringComparison.OrdinalIgnoreCase) && !Path.GetExtension(path).Equals(LnkExtension, StringComparison.OrdinalIgnoreCase))
         {
             Programs.Win32Program? app = Programs.Win32Program.GetAppFromPath(path);
-            if (app != null)
+            if (app is not null)
             {
                 Add(app);
                 _isDirty = true;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Utils/ComFreeHelper.cs

@@ -2,7 +2,6 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.System.Com;
@@ -27,7 +26,7 @@ public static class ComFreeHelper
     public static unsafe void ComObjectRelease<T>(T* comPtr)
         where T : unmanaged
     {
-        if (comPtr != null)
+        if (comPtr is not null)
         {
             ((IUnknown*)comPtr)->Release();
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Utils/ShellLinkHelper.cs

@@ -3,8 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Text;
-using ManagedCommon;
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.System.Com;
@@ -37,7 +35,7 @@ public class ShellLinkHelper : IShellLinkHelper
         IPersistFile* persistFile = null;
         Guid iid = typeof(IPersistFile).GUID;
         ((IUnknown*)link)->QueryInterface(&iid, (void**)&persistFile);
-        if (persistFile != null)
+        if (persistFile is not null)
         {
             using var persistFileHandle = new SafeComHandle((IntPtr)persistFile);
             try

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Utils/ShellLocalization.cs

@@ -45,7 +45,7 @@ public class ShellLocalization
 
             var filename = ComFreeHelper.GetStringAndFree(hr, filenamePtr);
 
-            if (filename == null)
+            if (filename is null)
             {
                 return string.Empty;
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Apps/Utils/ThemeHelper.cs

@@ -32,7 +32,7 @@ public static class ThemeHelper
 
         // Retrieve the registry value, which is a DWORD (0 or 1)
         var registryValueObj = Registry.GetValue(registryKey, registryValue, null);
-        if (registryValueObj != null)
+        if (registryValueObj is not null)
         {
             // 0 = Dark mode, 1 = Light mode
             var isLightMode = Convert.ToBoolean((int)registryValueObj, CultureInfo.InvariantCulture);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/AddBookmarkForm.cs

@@ -63,7 +63,7 @@ internal sealed partial class AddBookmarkForm : FormContent
     public override CommandResult SubmitForm(string payload)
     {
         var formInput = JsonNode.Parse(payload);
-        if (formInput == null)
+        if (formInput is null)
         {
             return CommandResult.GoHome();
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/BookmarkPlaceholderForm.cs

@@ -73,7 +73,7 @@ internal sealed partial class BookmarkPlaceholderForm : FormContent
         // parse the submitted JSON and then open the link
         var formInput = JsonNode.Parse(payload);
         var formObject = formInput?.AsObject();
-        if (formObject == null)
+        if (formObject is null)
         {
             return CommandResult.GoHome();
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/BookmarksCommandProvider.cs

@@ -49,7 +49,7 @@ public partial class BookmarksCommandProvider : CommandProvider
 
     private void SaveAndUpdateCommands()
     {
-        if (_bookmarks != null)
+        if (_bookmarks is not null)
         {
             var jsonPath = BookmarksCommandProvider.StateJsonPath();
             Bookmarks.WriteToFile(jsonPath, _bookmarks);
@@ -64,12 +64,12 @@ public partial class BookmarksCommandProvider : CommandProvider
         List<CommandItem> collected = [];
         collected.Add(new CommandItem(_addNewCommand));
 
-        if (_bookmarks == null)
+        if (_bookmarks is null)
         {
             LoadBookmarksFromFile();
         }
 
-        if (_bookmarks != null)
+        if (_bookmarks is not null)
         {
             collected.AddRange(_bookmarks.Data.Select(BookmarkToCommandItem));
         }
@@ -93,7 +93,7 @@ public partial class BookmarksCommandProvider : CommandProvider
             Logger.LogError(ex.Message);
         }
 
-        if (_bookmarks == null)
+        if (_bookmarks is null)
         {
             _bookmarks = new();
         }
@@ -134,7 +134,7 @@ public partial class BookmarksCommandProvider : CommandProvider
             name: Resources.bookmarks_delete_name,
             action: () =>
             {
-                if (_bookmarks != null)
+                if (_bookmarks is not null)
                 {
                     ExtensionHost.LogMessage($"Deleting bookmark ({bookmark.Name},{bookmark.Bookmark})");
 

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Bookmark/UrlCommand.cs

@@ -73,7 +73,7 @@ public partial class UrlCommand : InvokableCommand
         if (string.IsNullOrEmpty(args))
         {
             var uri = GetUri(exe);
-            if (uri != null)
+            if (uri is not null)
             {
                 _ = Launcher.LaunchUriAsync(uri);
             }
@@ -109,7 +109,7 @@ public partial class UrlCommand : InvokableCommand
         // First, try to get the icon from the thumbnail helper
         // This works for local files and folders
         icon = await MaybeGetIconForPath(target);
-        if (icon != null)
+        if (icon is not null)
         {
             return icon;
         }
@@ -142,7 +142,7 @@ public partial class UrlCommand : InvokableCommand
         {
             // If the executable exists, try to get the icon from the file
             icon = await MaybeGetIconForPath(fullExePath);
-            if (icon != null)
+            if (icon is not null)
             {
                 return icon;
             }
@@ -154,7 +154,7 @@ public partial class UrlCommand : InvokableCommand
         try
         {
             var uri = GetUri(baseString);
-            if (uri != null)
+            if (uri is not null)
             {
                 var hostname = uri.Host;
                 var faviconUrl = $"{uri.Scheme}://{hostname}/favicon.ico";
@@ -176,7 +176,7 @@ public partial class UrlCommand : InvokableCommand
         try
         {
             var stream = await ThumbnailHelper.GetThumbnail(target);
-            if (stream != null)
+            if (stream is not null)
             {
                 var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                 return new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Calc/Helper/NumberTranslator.cs

@@ -107,7 +107,7 @@ public class NumberTranslator
             // Currently, we only convert base literals (hexadecimal, binary, octal) to decimal.
             var converted = ConvertBaseLiteral(token, cultureTo);
 
-            if (converted != null)
+            if (converted is not null)
             {
                 outputBuilder.Append(converted);
                 continue;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Calc/Helper/ResultHelper.cs

@@ -16,7 +16,7 @@ public static class ResultHelper
     public static ListItem CreateResult(decimal? roundedResult, CultureInfo inputCulture, CultureInfo outputCulture, string query, ISettingsInterface settings, TypedEventHandler<object, object> handleSave)
     {
         // Return null when the expression is not a valid calculator query.
-        if (roundedResult == null)
+        if (roundedResult is null)
         {
             return null;
         }
@@ -48,7 +48,7 @@ public static class ResultHelper
     public static ListItem CreateResult(decimal? roundedResult, CultureInfo inputCulture, CultureInfo outputCulture, string query)
     {
         // Return null when the expression is not a valid calculator query.
-        if (roundedResult == null)
+        if (roundedResult is null)
         {
             return null;
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Calc/Pages/CalculatorListPage.cs

@@ -82,7 +82,7 @@ public sealed partial class CalculatorListPage : DynamicListPage
         {
             this._items.Clear();
 
-            if (result != null)
+            if (result is not null)
             {
                 this._items.Add(result);
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Calc/Pages/FallbackCalculatorItem.cs

@@ -28,7 +28,7 @@ public sealed partial class FallbackCalculatorItem : FallbackCommandItem
     {
         var result = QueryHelper.Query(query, _settings, true, null);
 
-        if (result == null)
+        if (result is null)
         {
             _copyCommand.Text = string.Empty;
             _copyCommand.Name = string.Empty;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.ClipboardHistory/Helpers/ClipboardHelper.cs

@@ -139,7 +139,7 @@ internal static class ClipboardHelper
         switch (clipboardFormat)
         {
             case ClipboardFormat.Text:
-                if (clipboardItem.Content == null)
+                if (clipboardItem.Content is null)
                 {
                     ExtensionHost.LogMessage(new LogMessage() { Message = "No valid clipboard content" });
                     return;
@@ -152,7 +152,7 @@ internal static class ClipboardHelper
                 break;
 
             case ClipboardFormat.Image:
-                if (clipboardItem.ImageData == null)
+                if (clipboardItem.ImageData is null)
                 {
                     ExtensionHost.LogMessage(new LogMessage() { Message = "No valid clipboard content" });
                     return;
@@ -240,7 +240,7 @@ internal static class ClipboardHelper
     internal static async Task<SoftwareBitmap?> GetClipboardImageContentAsync(DataPackageView clipboardData)
     {
         using var stream = await GetClipboardImageStreamAsync(clipboardData);
-        if (stream != null)
+        if (stream is not null)
         {
             var decoder = await BitmapDecoder.CreateAsync(stream);
             return await decoder.GetSoftwareBitmapAsync();
@@ -255,7 +255,7 @@ internal static class ClipboardHelper
         {
             var storageItems = await clipboardData.GetStorageItemsAsync();
             var file = storageItems.Count == 1 ? storageItems[0] as StorageFile : null;
-            if (file != null)
+            if (file is not null)
             {
                 return await file.OpenReadAsync();
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.ClipboardHistory/Models/ClipboardItem.cs

@@ -37,7 +37,7 @@ public class ClipboardItem
     }
 
     [MemberNotNullWhen(true, nameof(ImageData))]
-    private bool IsImage => ImageData != null;
+    private bool IsImage => ImageData is not null;
 
     [MemberNotNullWhen(true, nameof(Content))]
     private bool IsText => !string.IsNullOrEmpty(Content);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.ClipboardHistory/Pages/ClipboardHistoryListPage.cs

@@ -54,7 +54,7 @@ internal sealed partial class ClipboardHistoryListPage : ListPage
         try
         {
             var allowClipboardHistory = Registry.GetValue(registryKey, "AllowClipboardHistory", null);
-            return allowClipboardHistory != null ? (int)allowClipboardHistory == 0 : false;
+            return allowClipboardHistory is not null ? (int)allowClipboardHistory == 0 : false;
         }
         catch (Exception)
         {
@@ -100,7 +100,7 @@ internal sealed partial class ClipboardHistoryListPage : ListPage
                 {
                     var imageReceived = await item.Item.Content.GetBitmapAsync();
 
-                    if (imageReceived != null)
+                    if (imageReceived is not null)
                     {
                         item.ImageData = imageReceived;
                     }
@@ -141,7 +141,7 @@ internal sealed partial class ClipboardHistoryListPage : ListPage
         for (var i = 0; i < clipboardHistory.Count; i++)
         {
             var item = clipboardHistory[i];
-            if (item != null)
+            if (item is not null)
             {
                 listItems.Add(item.ToListItem());
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/FallbackOpenFileItem.cs

@@ -46,7 +46,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
             return;
         }
 
-        if (_suppressCallback != null && _suppressCallback(query))
+        if (_suppressCallback is not null && _suppressCallback(query))
         {
             Command = new NoOpCommand();
             Title = string.Empty;
@@ -71,7 +71,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
             try
             {
                 var stream = ThumbnailHelper.GetThumbnail(item.FullPath).Result;
-                if (stream != null)
+                if (stream is not null)
                 {
                     var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                     Icon = new IconInfo(data, data);
@@ -92,7 +92,7 @@ internal sealed partial class FallbackOpenFileItem : FallbackCommandItem, System
                 _searchEngine.Query(query, _queryCookie);
                 var results = _searchEngine.FetchItems(0, 20, _queryCookie, out var _);
 
-                if (results.Count == 0 || ((results[0] as IndexerListItem) == null))
+                if (results.Count == 0 || ((results[0] as IndexerListItem) is null))
                 {
                     // Exit 2: We searched for the file, and found nothing. Oh well.
                     // Hide ourselves.

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Indexer/DataSourceManager.cs

@@ -16,7 +16,7 @@ internal static class DataSourceManager
 
     public static IDBInitialize GetDataSource()
     {
-        if (_dataSource == null)
+        if (_dataSource is null)
         {
             InitializeDataSource();
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Indexer/SearchQuery.cs

@@ -12,7 +12,6 @@ using ManagedCsWin32;
 using Microsoft.CmdPal.Ext.Indexer.Indexer.OleDB;
 using Microsoft.CmdPal.Ext.Indexer.Indexer.SystemSearch;
 using Microsoft.CmdPal.Ext.Indexer.Indexer.Utils;
-using static Microsoft.CmdPal.Ext.Indexer.Indexer.Utils.NativeHelpers;
 
 namespace Microsoft.CmdPal.Ext.Indexer.Indexer;
 
@@ -54,14 +53,14 @@ internal sealed partial class SearchQuery : IDisposable
         try
         {
             queryTpTimer = new Timer(QueryTimerCallback, this, Timeout.Infinite, Timeout.Infinite);
-            if (queryTpTimer == null)
+            if (queryTpTimer is null)
             {
                 Logger.LogError("Failed to create query timer");
                 return;
             }
 
             queryCompletedEvent = new EventWaitHandle(false, EventResetMode.ManualReset);
-            if (queryCompletedEvent == null)
+            if (queryCompletedEvent is null)
             {
                 Logger.LogError("Failed to create query completed event");
                 return;
@@ -85,7 +84,7 @@ internal sealed partial class SearchQuery : IDisposable
         // Are we currently doing work? If so, let's cancel
         lock (_lockObject)
         {
-            if (queryTpTimer != null)
+            if (queryTpTimer is not null)
             {
                 queryTpTimer.Change(Timeout.Infinite, Timeout.Infinite);
                 queryTpTimer.Dispose();
@@ -117,7 +116,7 @@ internal sealed partial class SearchQuery : IDisposable
             try
             {
                 // We need to generate a search query string with the search text the user entered above
-                if (currentRowset != null)
+                if (currentRowset is not null)
                 {
                     // We have a previous rowset, this means the user is typing and we should store this
                     // recapture the where ID from this so the next ExecuteSync call will be faster
@@ -146,14 +145,14 @@ internal sealed partial class SearchQuery : IDisposable
         {
             getRow.GetRowFromHROW(null, rowHandle, ref Unsafe.AsRef(in IID.IPropertyStore), out var propertyStore);
 
-            if (propertyStore == null)
+            if (propertyStore is null)
             {
                 Logger.LogError("Failed to get IPropertyStore interface");
                 return false;
             }
 
             var searchResult = SearchResult.Create(propertyStore);
-            if (searchResult == null)
+            if (searchResult is null)
             {
                 Logger.LogError("Failed to create search result");
                 return false;
@@ -171,7 +170,7 @@ internal sealed partial class SearchQuery : IDisposable
 
     public bool FetchRows(int offset, int limit)
     {
-        if (currentRowset == null)
+        if (currentRowset is null)
         {
             Logger.LogError("No rowset to fetch rows from");
             return false;
@@ -241,7 +240,7 @@ internal sealed partial class SearchQuery : IDisposable
     {
         var queryStr = QueryStringBuilder.GeneratePrimingQuery();
         var rowset = ExecuteCommand(queryStr);
-        if (rowset != null)
+        if (rowset is not null)
         {
             reuseRowset = rowset;
             reuseWhereID = GetReuseWhereId(reuseRowset);
@@ -261,7 +260,7 @@ internal sealed partial class SearchQuery : IDisposable
             var guid = typeof(IDBCreateCommand).GUID;
             session.CreateSession(IntPtr.Zero, ref guid, out var ppDBSession);
 
-            if (ppDBSession == null)
+            if (ppDBSession is null)
             {
                 Logger.LogError("CreateSession failed");
                 return null;
@@ -271,7 +270,7 @@ internal sealed partial class SearchQuery : IDisposable
             guid = typeof(ICommandText).GUID;
             createCommand.CreateCommand(IntPtr.Zero, ref guid, out ICommandText commandText);
 
-            if (commandText == null)
+            if (commandText is null)
             {
                 Logger.LogError("Failed to get ICommandText interface");
                 return null;
@@ -342,13 +341,13 @@ internal sealed partial class SearchQuery : IDisposable
     {
         var rowsetInfo = (IRowsetInfo)rowset;
 
-        if (rowsetInfo == null)
+        if (rowsetInfo is null)
         {
             return 0;
         }
 
         var prop = GetPropset(rowsetInfo);
-        if (prop == null)
+        if (prop is null)
         {
             return 0;
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Indexer/SearchResult.cs

@@ -26,7 +26,7 @@ internal sealed class SearchResult
         ItemUrl = url;
         IsFolder = isFolder;
 
-        if (LaunchUri == null || LaunchUri.Length == 0)
+        if (LaunchUri is null || LaunchUri.Length == 0)
         {
             // Launch the file with the default app, so use the file path
             LaunchUri = filePath;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Indexer/Utils/QueryStringBuilder.cs

@@ -5,8 +5,6 @@
 using System;
 using System.Globalization;
 using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices;
-using System.Runtime.InteropServices.Marshalling;
 using ManagedCommon;
 using ManagedCsWin32;
 using Microsoft.CmdPal.Ext.Indexer.Indexer.SystemSearch;
@@ -28,7 +26,7 @@ internal sealed partial class QueryStringBuilder
 
     public static string GenerateQuery(string searchText, uint whereId)
     {
-        if (queryHelper == null)
+        if (queryHelper is null)
         {
             ISearchManager searchManager;
 
@@ -43,13 +41,13 @@ internal sealed partial class QueryStringBuilder
             }
 
             ISearchCatalogManager catalogManager = searchManager.GetCatalog(SystemIndex);
-            if (catalogManager == null)
+            if (catalogManager is null)
             {
                 throw new ArgumentException($"Failed to get catalog manager for {SystemIndex}");
             }
 
             queryHelper = catalogManager.GetQueryHelper();
-            if (queryHelper == null)
+            if (queryHelper is null)
             {
                 throw new ArgumentException("Failed to get query helper from catalog manager");
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Pages/ActionsListContextItem.cs

@@ -44,12 +44,12 @@ internal sealed partial class ActionsListContextItem : CommandContextItem, IDisp
     {
         lock (UpdateMoreCommandsLock)
         {
-            if (actionRuntime == null)
+            if (actionRuntime is null)
             {
                 actionRuntime = ActionRuntimeManager.InstanceAsync.GetAwaiter().GetResult();
             }
 
-            if (actionRuntime == null)
+            if (actionRuntime is null)
             {
                 return;
             }
@@ -62,7 +62,7 @@ internal sealed partial class ActionsListContextItem : CommandContextItem, IDisp
         {
             var extension = System.IO.Path.GetExtension(fullPath).ToLower(CultureInfo.InvariantCulture);
             ActionEntity entity = null;
-            if (extension != null)
+            if (extension is not null)
             {
                 if (extension == ".jpg" || extension == ".jpeg" || extension == ".png")
                 {
@@ -74,7 +74,7 @@ internal sealed partial class ActionsListContextItem : CommandContextItem, IDisp
                 }
             }
 
-            if (entity == null)
+            if (entity is null)
             {
                 entity = actionRuntime.EntityFactory.CreateFileEntity(fullPath);
             }
@@ -100,7 +100,7 @@ internal sealed partial class ActionsListContextItem : CommandContextItem, IDisp
     {
         lock (UpdateMoreCommandsLock)
         {
-            if (actionRuntime != null)
+            if (actionRuntime is not null)
             {
                 actionRuntime.ActionCatalog.Changed -= ActionCatalog_Changed;
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Pages/DirectoryExplorePage.cs

@@ -35,14 +35,14 @@ public sealed partial class DirectoryExplorePage : DynamicListPage
 
     public override void UpdateSearchText(string oldSearch, string newSearch)
     {
-        if (_directoryContents == null)
+        if (_directoryContents is null)
         {
             return;
         }
 
         if (string.IsNullOrEmpty(newSearch))
         {
-            if (_filteredContents != null)
+            if (_filteredContents is not null)
             {
                 _filteredContents = null;
                 RaiseItemsChanged(-1);
@@ -58,7 +58,7 @@ public sealed partial class DirectoryExplorePage : DynamicListPage
             newSearch,
             (s, i) => ListHelpers.ScoreListItem(s, i));
 
-        if (_filteredContents != null)
+        if (_filteredContents is not null)
         {
             lock (_filteredContents)
             {
@@ -75,12 +75,12 @@ public sealed partial class DirectoryExplorePage : DynamicListPage
 
     public override IListItem[] GetItems()
     {
-        if (_filteredContents != null)
+        if (_filteredContents is not null)
         {
             return _filteredContents.ToArray();
         }
 
-        if (_directoryContents != null)
+        if (_directoryContents is not null)
         {
             return _directoryContents.ToArray();
         }
@@ -120,7 +120,7 @@ public sealed partial class DirectoryExplorePage : DynamicListPage
                 try
                 {
                     var stream = ThumbnailHelper.GetThumbnail(item.FilePath).Result;
-                    if (stream != null)
+                    if (stream is not null)
                     {
                         var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                         icon = new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/Pages/DirectoryPage.cs

@@ -31,7 +31,7 @@ public sealed partial class DirectoryPage : ListPage
 
     public override IListItem[] GetItems()
     {
-        if (_directoryContents != null)
+        if (_directoryContents is not null)
         {
             return _directoryContents.ToArray();
         }
@@ -86,7 +86,7 @@ public sealed partial class DirectoryPage : ListPage
                 try
                 {
                     var stream = ThumbnailHelper.GetThumbnail(item.FilePath).Result;
-                    if (stream != null)
+                    if (stream is not null)
                     {
                         var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                         icon = new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Indexer/SearchEngine.cs

@@ -42,7 +42,7 @@ public sealed partial class SearchEngine : IDisposable
     {
         hasMore = false;
         var results = new List<IListItem>();
-        if (_searchQuery != null)
+        if (_searchQuery is not null)
         {
             var cookie = _searchQuery.Cookie;
             if (cookie == queryCookie)
@@ -59,7 +59,7 @@ public sealed partial class SearchEngine : IDisposable
                     try
                     {
                         var stream = ThumbnailHelper.GetThumbnail(result.LaunchUri).Result;
-                        if (stream != null)
+                        if (stream is not null)
                         {
                             var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                             icon = new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Helpers/RegistryHelper.cs

@@ -7,7 +7,6 @@ using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics;
 using System.Linq;
-using ManagedCommon;
 using Microsoft.CmdPal.Ext.Registry.Classes;
 using Microsoft.CmdPal.Ext.Registry.Constants;
 using Microsoft.CmdPal.Ext.Registry.Properties;
@@ -118,7 +117,7 @@ internal static class RegistryHelper
                 subKey = result.First().Key;
             }
 
-            if (result.Count > 1 || subKey == null)
+            if (result.Count > 1 || subKey is null)
             {
                 break;
             }
@@ -183,7 +182,7 @@ internal static class RegistryHelper
                 if (string.Equals(subKey, searchSubKey, StringComparison.OrdinalIgnoreCase))
                 {
                     var key = parentKey.OpenSubKey(subKey, RegistryKeyPermissionCheck.ReadSubTree);
-                    if (key != null)
+                    if (key is not null)
                     {
                         list.Add(new RegistryEntry(key));
                     }
@@ -194,7 +193,7 @@ internal static class RegistryHelper
                 try
                 {
                     var key = parentKey.OpenSubKey(subKey, RegistryKeyPermissionCheck.ReadSubTree);
-                    if (key != null)
+                    if (key is not null)
                     {
                         list.Add(new RegistryEntry(key));
                     }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Helpers/ResultHelper.cs

@@ -88,7 +88,7 @@ internal static class ResultHelper
                 foreach (var valueName in valueNames)
                 {
                     var value = key.GetValue(valueName);
-                    if (value != null)
+                    if (value is not null)
                     {
                         valueList.Add(KeyValuePair.Create(valueName, value));
                     }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Helpers/ValueHelper.cs

@@ -26,7 +26,7 @@ internal static class ValueHelper
     {
         var unformattedValue = key.GetValue(valueName);
 
-        if (unformattedValue == null)
+        if (unformattedValue is null)
         {
             throw new InvalidOperationException($"Cannot proceed when {nameof(unformattedValue)} is null.");
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Shell/Commands/ExecuteItem.cs

@@ -46,7 +46,7 @@ internal sealed partial class ExecuteItem : InvokableCommand
 
     private void Execute(Func<ProcessStartInfo, Process?> startProcess, ProcessStartInfo info)
     {
-        if (startProcess == null)
+        if (startProcess is null)
         {
             return;
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Shell/Helpers/ShellListPageHelpers.cs

@@ -126,7 +126,7 @@ public class ShellListPageHelpers
             return null;
         }
 
-        if (li != null)
+        if (li is not null)
         {
             li.TextToSuggest = searchText;
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Shell/Pages/RunExeItem.cs

@@ -78,7 +78,7 @@ internal sealed partial class RunExeItem : ListItem
         try
         {
             var stream = await ThumbnailHelper.GetThumbnail(FullExePath);
-            if (stream != null)
+            if (stream is not null)
             {
                 var data = new IconData(RandomAccessStreamReference.CreateFromStream(stream));
                 icon = new IconInfo(data, data);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Shell/Pages/ShellListPage.cs

@@ -245,14 +245,14 @@ internal sealed partial class ShellListPage : DynamicListPage, IDisposable
         var histItemsNotInSearch =
             _historyItems
                 .Where(kv => !kv.Key.Equals(newSearch, StringComparison.OrdinalIgnoreCase));
-        if (_exeItem != null)
+        if (_exeItem is not null)
         {
             // If we have an exe item, we want to remove it from the history items
             histItemsNotInSearch = histItemsNotInSearch
                 .Where(kv => !kv.Value.Title.Equals(_exeItem.Title, StringComparison.OrdinalIgnoreCase));
         }
 
-        if (_uriItem != null)
+        if (_uriItem is not null)
         {
             // If we have an uri item, we want to remove it from the history items
             histItemsNotInSearch = histItemsNotInSearch
@@ -307,8 +307,8 @@ internal sealed partial class ShellListPage : DynamicListPage, IDisposable
         }
 
         var filteredTopLevel = ListHelpers.FilterList(_topLevelItems, SearchText);
-        List<ListItem> uriItems = _uriItem != null ? [_uriItem] : [];
-        List<ListItem> exeItems = _exeItem != null ? [_exeItem] : [];
+        List<ListItem> uriItems = _uriItem is not null ? [_uriItem] : [];
+        List<ListItem> exeItems = _exeItem is not null ? [_exeItem] : [];
 
         return
             exeItems
@@ -459,7 +459,7 @@ internal sealed partial class ShellListPage : DynamicListPage, IDisposable
         var hist = _historyService.GetRunHistory();
         var histItems = hist
             .Select(h => (h, ShellListPageHelpers.ListItemForCommandString(h, AddToHistory)))
-            .Where(tuple => tuple.Item2 != null)
+            .Where(tuple => tuple.Item2 is not null)
             .Select(tuple => (tuple.h, tuple.Item2!))
             .ToList();
         _historyItems.Clear();

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Shell/PathListItem.cs

@@ -72,7 +72,7 @@ internal sealed partial class PathListItem : ListItem
         _icon = new Lazy<IconInfo>(() =>
         {
             var iconStream = ThumbnailHelper.GetThumbnail(path).Result;
-            var icon = iconStream != null ? IconInfo.FromStream(iconStream) :
+            var icon = iconStream is not null ? IconInfo.FromStream(iconStream) :
              _isDirectory ? Icons.FolderIcon : Icons.RunV2Icon;
             return icon;
         });

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.System/FallbackSystemCommandItem.cs

@@ -57,7 +57,7 @@ internal sealed partial class FallbackSystemCommandItem : FallbackCommandItem
             }
         }
 
-        if (result == null)
+        if (result is null)
         {
             Command = null;
             Title = string.Empty;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.System/Helpers/NetworkConnectionProperties.cs

@@ -155,7 +155,7 @@ internal sealed class NetworkConnectionProperties
     internal static List<NetworkConnectionProperties> GetList()
     {
         var interfaces = NetworkInterface.GetAllNetworkInterfaces()
-                                         .Where(x => x.NetworkInterfaceType != NetworkInterfaceType.Loopback && x.GetPhysicalAddress() != null)
+                                         .Where(x => x.NetworkInterfaceType != NetworkInterfaceType.Loopback && x.GetPhysicalAddress() is not null)
                                          .Select(i => new NetworkConnectionProperties(i))
                                          .OrderByDescending(i => i.IPv4) // list IPv4 first
                                          .ThenBy(i => i.IPv6Primary) // then IPv6
@@ -195,9 +195,9 @@ internal sealed class NetworkConnectionProperties
             CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Ip6Site}:**\n\n* ", IPv6SiteLocal) +
             CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Ip6Unique}:**\n\n* ", IPv6UniqueLocal) +
             CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Gateways}:**\n\n* ", Gateways) +
-            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Dhcp}:**\n\n* ", DhcpServers == null ? string.Empty : DhcpServers) +
-            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Dns}:**\n\n* ", DnsServers == null ? string.Empty : DnsServers) +
-            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Wins}:**\n\n* ", WinsServers == null ? string.Empty : WinsServers) +
+            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Dhcp}:**\n\n* ", DhcpServers is null ? string.Empty : DhcpServers) +
+            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Dns}:**\n\n* ", DnsServers is null ? string.Empty : DnsServers) +
+            CreateIpInfoForDetailsText($"**{Resources.Microsoft_plugin_sys_Wins}:**\n\n* ", WinsServers is null ? string.Empty : WinsServers) +
             $"\n\n**{Resources.Microsoft_plugin_sys_AdapterName}:** {Adapter}" +
             $"\n\n**{Resources.Microsoft_plugin_sys_PhysicalAddress}:** {PhysicalAddress}" +
             $"\n\n**{Resources.Microsoft_plugin_sys_Speed}:** {GetFormattedSpeedValue(Speed)}";

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/FallbackTimeDateItem.cs

@@ -4,11 +4,9 @@
 
 using System;
 using System.Collections.Generic;
-using System.Drawing;
 using System.Globalization;
 using System.Linq;
 using Microsoft.CmdPal.Ext.TimeDate.Helpers;
-using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
 
 namespace Microsoft.CmdPal.Ext.TimeDate;
@@ -66,7 +64,7 @@ internal sealed partial class FallbackTimeDateItem : FallbackCommandItem
             }
         }
 
-        if (result != null)
+        if (result is not null)
         {
             Title = result.Title;
             Subtitle = result.Subtitle;
@@ -90,7 +88,7 @@ internal sealed partial class FallbackTimeDateItem : FallbackCommandItem
 
         foreach (var option in _validOptions)
         {
-            if (option == null)
+            if (option is null)
             {
                 continue;
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/Helpers/AvailableResultsList.cs

@@ -29,7 +29,7 @@ internal static class AvailableResultsList
 
         var timeExtended = timeLongFormat ?? settings.TimeWithSecond;
         var dateExtended = dateLongFormat ?? settings.DateWithWeekday;
-        var isSystemDateTime = timestamp == null;
+        var isSystemDateTime = timestamp is null;
         var dateTimeNow = timestamp ?? DateTime.Now;
         var dateTimeNowUtc = dateTimeNow.ToUniversalTime();
         var firstWeekRule = firstWeekOfYear ?? TimeAndDateHelper.GetCalendarWeekRule(settings.FirstWeekOfYear);

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.TimeDate/Helpers/SettingsManager.cs

@@ -103,7 +103,7 @@ public class SettingsManager : JsonSettingsManager, ISettingsInterface
     {
         get
         {
-            if (_firstWeekOfYear.Value == null || string.IsNullOrEmpty(_firstWeekOfYear.Value))
+            if (_firstWeekOfYear.Value is null || string.IsNullOrEmpty(_firstWeekOfYear.Value))
             {
                 return -1;
             }
@@ -123,7 +123,7 @@ public class SettingsManager : JsonSettingsManager, ISettingsInterface
     {
         get
         {
-            if (_firstDayOfWeek.Value == null || string.IsNullOrEmpty(_firstDayOfWeek.Value))
+            if (_firstDayOfWeek.Value is null || string.IsNullOrEmpty(_firstDayOfWeek.Value))
             {
                 return -1;
             }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WebSearch/Helpers/DefaultBrowserInfo.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading;
 using ManagedCommon;
@@ -87,7 +86,7 @@ public static class DefaultBrowserInfo
                 var appName = GetRegistryValue($@"HKEY_CLASSES_ROOT\{progId}\Application", "ApplicationName")
                     ?? GetRegistryValue($@"HKEY_CLASSES_ROOT\{progId}", "FriendlyTypeName");
 
-                if (appName != null)
+                if (appName is not null)
                 {
                     // Handle indirect strings:
                     if (appName.StartsWith('@'))

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WebSearch/Helpers/SettingsManager.cs

@@ -67,7 +67,7 @@ public class SettingsManager : JsonSettingsManager
 
     public void SaveHistory(HistoryItem historyItem)
     {
-        if (historyItem == null)
+        if (historyItem is null)
         {
             return;
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WebSearch/Pages/WebSearchListPage.cs

@@ -34,7 +34,7 @@ internal sealed partial class WebSearchListPage : DynamicListPage
         Id = "com.microsoft.cmdpal.websearch";
         _settingsManager = settingsManager;
         _historyItems = _settingsManager.ShowHistory != Resources.history_none ? _settingsManager.LoadHistory() : null;
-        if (_historyItems != null)
+        if (_historyItems is not null)
         {
             _allItems.AddRange(_historyItems);
         }
@@ -55,7 +55,7 @@ internal sealed partial class WebSearchListPage : DynamicListPage
         ArgumentNullException.ThrowIfNull(query);
         IEnumerable<ListItem>? filteredHistoryItems = null;
 
-        if (_historyItems != null)
+        if (_historyItems is not null)
         {
             filteredHistoryItems = _settingsManager.ShowHistory != Resources.history_none ? ListHelpers.FilterList(_historyItems, query).OfType<ListItem>() : null;
         }
@@ -74,7 +74,7 @@ internal sealed partial class WebSearchListPage : DynamicListPage
             results.Add(result);
         }
 
-        if (filteredHistoryItems != null)
+        if (filteredHistoryItems is not null)
         {
             results.AddRange(filteredHistoryItems);
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WinGet/Pages/InstallPackageCommand.cs

@@ -5,7 +5,6 @@
 using System;
 using System.Globalization;
 using System.Text;
-using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
@@ -79,7 +78,7 @@ public partial class InstallPackageCommand : InvokableCommand
     {
         // TODO: LOCK in here, so this can only be invoked once until the
         // install / uninstall is done. Just use like, an atomic
-        if (_installTask != null)
+        if (_installTask is not null)
         {
             return CommandResult.KeepOpen();
         }
@@ -143,7 +142,7 @@ public partial class InstallPackageCommand : InvokableCommand
             {
                 await Task.Delay(2500).ConfigureAwait(false);
 
-                if (_installTask == null)
+                if (_installTask is null)
                 {
                     WinGetExtensionHost.Instance.HideStatus(_installBanner);
                 }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WinGet/Pages/InstallPackageListItem.cs

@@ -34,7 +34,7 @@ public partial class InstallPackageListItem : ListItem
 
         var version = _package.DefaultInstallVersion ?? _package.InstalledVersion;
         var versionTagText = "Unknown";
-        if (version != null)
+        if (version is not null)
         {
             versionTagText = version.Version == "Unknown" && version.PackageCatalog.Info.Id == "StoreEdgeFD" ? "msstore" : version.Version;
         }
@@ -60,11 +60,11 @@ public partial class InstallPackageListItem : ListItem
             Logger.LogWarning($"{ex.ErrorCode}");
         }
 
-        if (metadata != null)
+        if (metadata is not null)
         {
             if (metadata.Tags.Where(t => t.Equals(WinGetExtensionPage.ExtensionsTag, StringComparison.OrdinalIgnoreCase)).Any())
             {
-                if (_installCommand != null)
+                if (_installCommand is not null)
                 {
                     _installCommand.SkipDependencies = true;
                 }
@@ -172,7 +172,7 @@ public partial class InstallPackageListItem : ListItem
             return;
         }
 
-        var isInstalled = _package.InstalledVersion != null;
+        var isInstalled = _package.InstalledVersion is not null;
 
         var installedState = isInstalled ?
             (_package.IsUpdateAvailable ?
@@ -193,11 +193,11 @@ public partial class InstallPackageListItem : ListItem
                 Icon = Icons.DeleteIcon,
             };
 
-            if (WinGetStatics.AppSearchCallback != null)
+            if (WinGetStatics.AppSearchCallback is not null)
             {
                 var callback = WinGetStatics.AppSearchCallback;
-                var installedApp = callback(_package.DefaultInstallVersion == null ? _package.Name : _package.DefaultInstallVersion.DisplayName);
-                if (installedApp != null)
+                var installedApp = callback(_package.DefaultInstallVersion is null ? _package.Name : _package.DefaultInstallVersion.DisplayName);
+                if (installedApp is not null)
                 {
                     this.Command = installedApp.Command;
                     contextMenu = [.. installedApp.MoreCommands];

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WinGet/Pages/WinGetExtensionPage.cs

@@ -53,7 +53,7 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
         {
             // emptySearchForTag ===
             // we don't have results yet, we haven't typed anything, and we're searching for a tag
-            var emptySearchForTag = _results == null &&
+            var emptySearchForTag = _results is null &&
                 string.IsNullOrEmpty(SearchText) &&
                 HasTag;
 
@@ -64,7 +64,7 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
                 return items;
             }
 
-            if (_results != null && _results.Any())
+            if (_results is not null && _results.Any())
             {
                 ListItem[] results = _results.Select(PackageToListItem).ToArray();
                 IsLoading = false;
@@ -100,7 +100,7 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
     private void DoUpdateSearchText(string newSearch)
     {
         // Cancel any ongoing search
-        if (_cancellationTokenSource != null)
+        if (_cancellationTokenSource is not null)
         {
             Logger.LogDebug("Cancelling old search", memberName: nameof(DoUpdateSearchText));
             _cancellationTokenSource.Cancel();
@@ -221,7 +221,7 @@ internal sealed partial class WinGetExtensionPage : DynamicListPage, IDisposable
         // WinGetStatics static ctor when we were created.
         PackageCatalog catalog = await catalogTask.Value;
 
-        if (catalog == null)
+        if (catalog is null)
         {
             // This error should have already been displayed by WinGetStatics
             return [];

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Commands/SwitchToWindowCommand.cs

@@ -18,10 +18,10 @@ internal sealed partial class SwitchToWindowCommand : InvokableCommand
     {
         Name = Resources.switch_to_command_title;
         _window = window;
-        if (_window != null)
+        if (_window is not null)
         {
             var p = Process.GetProcessById((int)_window.Process.ProcessID);
-            if (p != null)
+            if (p is not null)
             {
                 try
                 {

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Components/ResultHelper.cs

@@ -23,7 +23,7 @@ internal static class ResultHelper
     /// <returns>List of results</returns>
     internal static List<WindowWalkerListItem> GetResultList(List<SearchResult> searchControllerResults, bool isKeywordSearch)
     {
-        if (searchControllerResults == null || searchControllerResults.Count == 0)
+        if (searchControllerResults is null || searchControllerResults.Count == 0)
         {
             return [];
         }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Helpers/VirtualDesktopHelper.cs

@@ -83,7 +83,7 @@ public class VirtualDesktopHelper
     /// <summary>
     /// Gets a value indicating whether the Virtual Desktop Manager is initialized successfully
     /// </summary>
-    public bool VirtualDesktopManagerInitialized => _virtualDesktopManager != null;
+    public bool VirtualDesktopManagerInitialized => _virtualDesktopManager is not null;
 
     /// <summary>
     /// Method to update the list of Virtual Desktops from Registry
@@ -98,10 +98,10 @@ public class VirtualDesktopHelper
 
         // List of all desktops
         using RegistryKey? virtualDesktopKey = Registry.CurrentUser.OpenSubKey(registryExplorerVirtualDesktops, false);
-        if (virtualDesktopKey != null)
+        if (virtualDesktopKey is not null)
         {
             var allDeskValue = (byte[]?)virtualDesktopKey.GetValue("VirtualDesktopIDs", null) ?? Array.Empty<byte>();
-            if (allDeskValue != null)
+            if (allDeskValue is not null)
             {
                 // We clear only, if we can read from registry. Otherwise, we keep the existing values.
                 _availableDesktops.Clear();
@@ -124,10 +124,10 @@ public class VirtualDesktopHelper
         // Guid for current desktop
         var virtualDesktopsKeyName = _isWindowsEleven ? registryExplorerVirtualDesktops : registrySessionVirtualDesktops;
         using RegistryKey? virtualDesktopsKey = Registry.CurrentUser.OpenSubKey(virtualDesktopsKeyName, false);
-        if (virtualDesktopsKey != null)
+        if (virtualDesktopsKey is not null)
         {
             var currentVirtualDesktopValue = virtualDesktopsKey.GetValue("CurrentVirtualDesktop", null);
-            if (currentVirtualDesktopValue != null)
+            if (currentVirtualDesktopValue is not null)
             {
                 _currentDesktop = new Guid((byte[])currentVirtualDesktopValue);
             }
@@ -268,7 +268,7 @@ public class VirtualDesktopHelper
         using RegistryKey? deskSubKey = Registry.CurrentUser.OpenSubKey(registryPath, false);
         var desktopName = deskSubKey?.GetValue("Name");
 
-        return (desktopName != null) ? (string)desktopName : defaultName;
+        return (desktopName is not null) ? (string)desktopName : defaultName;
     }
 
     /// <summary>
@@ -313,7 +313,7 @@ public class VirtualDesktopHelper
     /// <returns>HResult of the called method as integer.</returns>
     public int GetWindowDesktopId(IntPtr hWindow, out Guid desktopId)
     {
-        if (_virtualDesktopManager == null)
+        if (_virtualDesktopManager is null)
         {
             ExtensionHost.LogMessage(new LogMessage() { Message = "VirtualDesktopHelper.GetWindowDesktopId() failed: The instance of <IVirtualDesktopHelper> isn't available." });
             desktopId = Guid.Empty;
@@ -330,7 +330,7 @@ public class VirtualDesktopHelper
     /// <returns>An instance of <see cref="VDesktop"/> for the desktop where the window is assigned to, or an empty instance of <see cref="VDesktop"/> on failure.</returns>
     public VDesktop GetWindowDesktop(IntPtr hWindow)
     {
-        if (_virtualDesktopManager == null)
+        if (_virtualDesktopManager is null)
         {
             ExtensionHost.LogMessage(new LogMessage() { Message = "VirtualDesktopHelper.GetWindowDesktop() failed: The instance of <IVirtualDesktopHelper> isn't available." });
             return CreateVDesktopInstance(Guid.Empty);
@@ -348,7 +348,7 @@ public class VirtualDesktopHelper
     /// <returns>Type of <see cref="VirtualDesktopAssignmentType"/>.</returns>
     public VirtualDesktopAssignmentType GetWindowDesktopAssignmentType(IntPtr hWindow, Guid? desktop = null)
     {
-        if (_virtualDesktopManager == null)
+        if (_virtualDesktopManager is null)
         {
             ExtensionHost.LogMessage(new LogMessage() { Message = "VirtualDesktopHelper.GetWindowDesktopAssignmentType() failed: The instance of <IVirtualDesktopHelper> isn't available." });
             return VirtualDesktopAssignmentType.Unknown;
@@ -415,7 +415,7 @@ public class VirtualDesktopHelper
     /// <returns><see langword="True"/> on success and <see langword="false"/> on failure.</returns>
     public bool MoveWindowToDesktop(IntPtr hWindow, ref Guid desktopId)
     {
-        if (_virtualDesktopManager == null)
+        if (_virtualDesktopManager is null)
         {
             ExtensionHost.LogMessage(new LogMessage() { Message = "VirtualDesktopHelper.MoveWindowToDesktop() failed: The instance of <IVirtualDesktopHelper> isn't available." });
             return false;

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowsServices/Helpers/ServiceHelper.cs

@@ -47,7 +47,7 @@ public static class ServiceHelper
         var result = serviceList.Select(s =>
         {
             var serviceResult = ServiceResult.CreateServiceController(s);
-            if (serviceResult == null)
+            if (serviceResult is null)
             {
                 return null;
             }
@@ -98,7 +98,7 @@ public static class ServiceHelper
                 // ToolTipData = new ToolTipData(serviceResult.DisplayName, serviceResult.ServiceName),
                 // IcoPath = icoPath,
             };
-        }).Where(s => s != null);
+        }).Where(s => s is not null);
 
         return result;
     }

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowsSettings/Helpers/UnsupportedSettingsHelper.cs

@@ -49,8 +49,8 @@ internal static class UnsupportedSettingsHelper
             : currentBuildNumber;
 
         var filteredSettingsList = windowsSettings.Settings.Where(found
-            => (found.DeprecatedInBuild == null || currentWindowsBuild < found.DeprecatedInBuild)
-            && (found.IntroducedInBuild == null || currentWindowsBuild >= found.IntroducedInBuild));
+            => (found.DeprecatedInBuild is null || currentWindowsBuild < found.DeprecatedInBuild)
+            && (found.IntroducedInBuild is null || currentWindowsBuild >= found.IntroducedInBuild));
 
         filteredSettingsList = filteredSettingsList.OrderBy(found => found.Name);
 

src/modules/cmdpal/ext/SamplePagesExtension/Pages/SampleContentPage.cs

@@ -309,7 +309,7 @@ internal sealed partial class SampleContentForm : FormContent
     public override CommandResult SubmitForm(string payload)
     {
         var formInput = JsonNode.Parse(payload)?.AsObject();
-        if (formInput == null)
+        if (formInput is null)
         {
             return CommandResult.GoHome();
         }

src/modules/cmdpal/ext/SamplePagesExtension/SampleUpdatingItemsPage.cs

@@ -24,7 +24,7 @@ public partial class SampleUpdatingItemsPage : ListPage
 
     public override IListItem[] GetItems()
     {
-        if (timer == null)
+        if (timer is null)
         {
             timer = new Timer(500);
             timer.Elapsed += (object source, ElapsedEventArgs e) =>