Use is operator for null check instead of ==

src/OrchardCore.Modules/OrchardCore.Admin/AdminAreaControllerRouteMapper.cs

@@ -24,7 +24,7 @@ public bool TryMapAreaControllerRoute(IEndpointRouteBuilder routes, ControllerAc
             var controllerAttribute = descriptor.ControllerTypeInfo.GetCustomAttribute<AdminAttribute>();
             var actionAttribute = descriptor.MethodInfo.GetCustomAttribute<AdminAttribute>();
 
-            if (descriptor.ControllerName != "Admin" && controllerAttribute == null && actionAttribute == null)
+            if (descriptor.ControllerName != "Admin" && controllerAttribute is null && actionAttribute is null)
             {
                 return false;
             }

src/OrchardCore.Modules/OrchardCore.Admin/AdminPageRouteModelConvention.cs

@@ -16,7 +16,7 @@ public void Apply(PageRouteModel model)
         {
             var route = model.Selectors.FirstOrDefault()?.AttributeRouteModel;
 
-            if (route == null)
+            if (route is null)
             {
                 return;
             }

src/OrchardCore.Modules/OrchardCore.Admin/AdminPageRouteModelProvider.cs

@@ -50,7 +50,7 @@ public void OnProvidersExecuting(PageRouteModelProviderContext context)
                 {
                     var attribute = type.GetCustomAttribute<AdminAttribute>();
 
-                    if (attribute != null)
+                    if (attribute is not null)
                     {
                         adminPaths.Add(descriptor.RelativePath);
                         break;

src/OrchardCore.Modules/OrchardCore.Admin/Views/Navbar.DetailAdmin.cshtml

@@ -1,4 +1,4 @@
-@if (Model.Content == null)
+@if (Model.Content is null)
 {
     return;
 }

src/OrchardCore.Modules/OrchardCore.Admin/Views/Navbar.cshtml

@@ -6,7 +6,7 @@
 @inject IDisplayManager<Navbar> DisplayManager
 @inject IUpdateModelAccessor UpdateModelAccessor
 
-@if (Model.Content == null)
+@if (Model.Content is null)
 {
     var shape = await DisplayManager.BuildDisplayAsync(UpdateModelAccessor.ModelUpdater, (string)Model.Metadata.DisplayType);
 

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Controllers/DashboardController.cs

@@ -155,7 +155,7 @@ public async Task<IActionResult> Update([FromForm] DashboardPartViewModel[] part
             // Load the latest version first if any.
             var latestItems = await _contentManager.GetAsync(contentItemIds, VersionOptions.Latest);
 
-            if (latestItems == null)
+            if (latestItems is null)
             {
                 return NotFound();
             }
@@ -165,7 +165,7 @@ public async Task<IActionResult> Update([FromForm] DashboardPartViewModel[] part
             foreach (var contentItem in latestItems)
             {
                 var dashboardPart = contentItem.As<DashboardPart>();
-                if (dashboardPart == null)
+                if (dashboardPart is null)
                 {
                     return Forbid();
                 }
@@ -184,7 +184,7 @@ public async Task<IActionResult> Update([FromForm] DashboardPartViewModel[] part
                 {
                     var publishedVersion = publishedItems.FirstOrDefault(p => p.ContentItemId == contentItem.ContentItemId);
                     var publishedMetaData = publishedVersion?.As<DashboardPart>();
-                    if (publishedMetaData != null)
+                    if (publishedMetaData is not null)
                     {
                         publishedMetaData.Position = partViewModel.Position;
                         publishedMetaData.Width = partViewModel.Width;
@@ -195,7 +195,7 @@ public async Task<IActionResult> Update([FromForm] DashboardPartViewModel[] part
                 }
             }
 
-            if (Request.Headers != null && Request.Headers.XRequestedWith == "XMLHttpRequest")
+            if (Request.Headers is not null && Request.Headers.XRequestedWith == "XMLHttpRequest")
             {
                 return Ok();
             }

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Drivers/DashboardContentDisplayDriver.cs

@@ -35,7 +35,7 @@ public override async Task<IDisplayResult> DisplayAsync(ContentItem model, Build
             var dashboardFeature = httpContext.Features.Get<DashboardFeature>();
 
             // Return if it's not Manage dashboard request 
-            if (dashboardFeature == null || !dashboardFeature.IsManageRequest)
+            if (dashboardFeature is null || !dashboardFeature.IsManageRequest)
             {
                 return null;
             }

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Indexes/DashboardPartIndex.cs

@@ -24,7 +24,7 @@ public override void Describe(DescribeContext<ContentItem> context)
                         return null;
                     }
 
-                    if (dashboardPart != null)
+                    if (dashboardPart is not null)
                     {
                         return new DashboardPartIndex
                         {

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/Dashboard/Manage.cshtml

@@ -193,7 +193,7 @@
             },
             start: function (e, ui) {
 
-                if(_menu != null){
+                if(_menu is not null){
                     $(document).trigger('click');
                 }
 
@@ -218,7 +218,7 @@
             helper: "ui-resizable-helper"
 ,
             start: function (event, ui) {
-                if(_menu != null){
+                if(_menu is not null){
                     $(document).trigger('click');
                 }
                 setUndoValues();

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/DashboardWidget-ContentsMetadata.DetailAdmin.cshtml

@@ -9,7 +9,7 @@
 
 }
 
-@if (dashboardFeature != null && dashboardFeature.IsManageRequest)
+@if (dashboardFeature is not null && dashboardFeature.IsManageRequest)
 {
     ContentItem contentItem = Model.ContentItem;
     var modifiedUtc = contentItem.ModifiedUtc?.ToString("yyyy-MM-ddTHH:mm:sszzz", CultureInfo.InvariantCulture);

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/DashboardWidget.DetailAdmin.cshtml

@@ -1,10 +1,10 @@
 <div class="card h-100 @string.Join(' ', Model.Classes.ToArray())">
-    @if (Model.Header != null || Model.Leading != null || Model.ActionsMenu != null)
+    @if (Model.Header is not null || Model.Leading is not null || Model.ActionsMenu is not null)
     {
         <div class="card-header">
             @await DisplayAsync(Model.Leading)
             @await DisplayAsync(Model.Header)
-            @if (Model.ActionsMenu != null)
+            @if (Model.ActionsMenu is not null)
             {
                 <div class="btn-group float-end" title="@T["Actions"]">
                     <button type="button" class="btn btn-sm " data-bs-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
@@ -18,7 +18,7 @@
         </div>
     }
     <div class="dashboard-body-container card-body p-0 h-100">
-        @if (Model.Tags != null || Model.Meta != null)
+        @if (Model.Tags is not null || Model.Meta is not null)
         {
             <div class="dashboard-meta">
                 @await DisplayAsync(Model.Meta)
@@ -27,7 +27,7 @@
         }
         @await DisplayAsync(Model.Content)
     </div>
-    @if (Model.Footer != null)
+    @if (Model.Footer is not null)
     {
         <div class="card-footer">
             @await DisplayAsync(Model.Footer)

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/DashboardWidget.Summary.cshtml

@@ -1,9 +1,9 @@
 <div class="@string.Join(" ", Model.Classes.ToArray())">
-    @if (Model.Header != null || Model.Meta != null)
+    @if (Model.Header is not null || Model.Meta is not null)
     {
         <div class="widget-header">
             @await DisplayAsync(Model.Header)
-            @if (Model.Meta != null)
+            @if (Model.Meta is not null)
             {
                 <div class="widget-metadata">
                     @await DisplayAsync(Model.Meta)
@@ -14,7 +14,7 @@
     <div class="widget-body">
         @await DisplayAsync(Model.Content)
     </div>
-    @if (Model.Footer != null)
+    @if (Model.Footer is not null)
     {
         <div class="widget-footer">
             @await DisplayAsync(Model.Footer)

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/DashboardWidget.SummaryAdmin.cshtml

@@ -20,26 +20,26 @@
             @contentItem
         }
         - <small class="text-muted">@contentItem.ContentType</small>
-        @if (Model.Header != null)
+        @if (Model.Header is not null)
         {
             <div class="header">@await DisplayAsync(Model.Header)</div>
         }
-        @if (Model.Tags != null)
+        @if (Model.Tags is not null)
         {
             @await DisplayAsync(Model.Tags)
         }
-        @if (Model.Meta != null)
+        @if (Model.Meta is not null)
         {
         <div class="d-inline">@await DisplayAsync(Model.Meta)</div>
         }
     </div>
     <div class="col-xl-3 col-sm-12">
         <div class="float-end button-group">
-            @if (Model.Actions != null)
+            @if (Model.Actions is not null)
             {
                 @await DisplayAsync(Model.Actions)
             }
-            @if (Model.ActionsMenu != null)
+            @if (Model.ActionsMenu is not null)
             {
                 <div class="btn-group">
                     <button type="button" class="btn btn-sm text-secondary" data-bs-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
@@ -54,7 +54,7 @@
     </div>
 </div>
 
-@if (Model.Content != null)
+@if (Model.Content is not null)
 {
     <div class="primary">@await DisplayAsync(Model.Content)</div>
 }

src/OrchardCore.Modules/OrchardCore.AdminDashboard/Views/DashboardWidget.cshtml

@@ -1,9 +1,9 @@
 <div class="@string.Join(" ", Model.Classes.ToArray())">
-    @if (Model.Header != null || Model.Meta != null)
+    @if (Model.Header is not null || Model.Meta is not null)
     {
         <div class="widget-header">
             @await DisplayAsync(Model.Header)
-            @if (Model.Meta != null)
+            @if (Model.Meta is not null)
             {
                 <div class="widget-metadata">
                     @await DisplayAsync(Model.Meta)
@@ -14,7 +14,7 @@
     <div class="widget-body">
         @await DisplayAsync(Model.Content)
     </div>
-    @if (Model.Footer != null)
+    @if (Model.Footer is not null)
     {
         <div class="widget-footer">
             @await DisplayAsync(Model.Footer)

src/OrchardCore.Modules/OrchardCore.AdminMenu/AdminNodes/LinkAdminNodeDriver.cs

@@ -62,7 +62,7 @@ public override async Task<IDisplayResult> UpdateAsync(LinkAdminNode treeNode, I
             treeNode.LinkUrl = model.LinkUrl;
             treeNode.IconClass = model.IconClass;
 
-            var selectedPermissions = (model.SelectedPermissionNames == null ? [] : model.SelectedPermissionNames.Split(',', StringSplitOptions.RemoveEmptyEntries));
+            var selectedPermissions = (model.SelectedPermissionNames is null ? [] : model.SelectedPermissionNames.Split(',', StringSplitOptions.RemoveEmptyEntries));
 
             var permissions = await _adminMenuPermissionService.GetPermissionsAsync();
             treeNode.PermissionNames = permissions

src/OrchardCore.Modules/OrchardCore.AdminMenu/AdminNodes/LinkAdminNodeNavigationBuilder.cs

@@ -33,7 +33,7 @@ public LinkAdminNodeNavigationBuilder(
         public Task BuildNavigationAsync(MenuItem menuItem, NavigationBuilder builder, IEnumerable<IAdminNodeNavigationBuilder> treeNodeBuilders)
         {
             var node = menuItem as LinkAdminNode;
-            if (node == null || string.IsNullOrEmpty(node.LinkText) || !node.Enabled)
+            if (node is null || string.IsNullOrEmpty(node.LinkText) || !node.Enabled)
             {
                 return Task.CompletedTask;
             }

src/OrchardCore.Modules/OrchardCore.AdminMenu/AdminNodes/PlaceholderAdminNodeDriver.cs

@@ -60,7 +60,7 @@ public override async Task<IDisplayResult> UpdateAsync(PlaceholderAdminNode tree
             treeNode.LinkText = model.LinkText;
             treeNode.IconClass = model.IconClass;
 
-            var selectedPermissions = (model.SelectedPermissionNames == null ? Array.Empty<string>() : model.SelectedPermissionNames.Split(',', StringSplitOptions.RemoveEmptyEntries));
+            var selectedPermissions = (model.SelectedPermissionNames is null ? Array.Empty<string>() : model.SelectedPermissionNames.Split(',', StringSplitOptions.RemoveEmptyEntries));
             var permissions = await _adminMenuPermissionService.GetPermissionsAsync();
             treeNode.PermissionNames = permissions
                 .Where(p => selectedPermissions.Contains(p.Name))

src/OrchardCore.Modules/OrchardCore.AdminMenu/AdminNodes/PlaceholderAdminNodeNavigationBuilder.cs

@@ -26,7 +26,7 @@ public Task BuildNavigationAsync(MenuItem menuItem, NavigationBuilder builder, I
         {
             var node = menuItem as PlaceholderAdminNode;
 
-            if (node == null || string.IsNullOrEmpty(node.LinkText) || !node.Enabled)
+            if (node is null || string.IsNullOrEmpty(node.LinkText) || !node.Enabled)
             {
                 return Task.CompletedTask;
             }

src/OrchardCore.Modules/OrchardCore.AdminMenu/Controllers/MenuController.cs

@@ -165,7 +165,7 @@ public async Task<IActionResult> Edit(string id)
             var adminMenuList = await _adminMenuService.GetAdminMenuListAsync();
             var adminMenu = _adminMenuService.GetAdminMenuById(adminMenuList, id);
 
-            if (adminMenu == null)
+            if (adminMenu is null)
             {
                 return NotFound();
             }
@@ -190,7 +190,7 @@ public async Task<IActionResult> Edit(AdminMenuEditViewModel model)
             var adminMenuList = await _adminMenuService.LoadAdminMenuListAsync();
             var adminMenu = _adminMenuService.GetAdminMenuById(adminMenuList, model.Id);
 
-            if (adminMenu == null)
+            if (adminMenu is null)
             {
                 return NotFound();
             }
@@ -220,7 +220,7 @@ public async Task<IActionResult> Delete(string id)
             var adminMenuList = await _adminMenuService.LoadAdminMenuListAsync();
             var adminMenu = _adminMenuService.GetAdminMenuById(adminMenuList, id);
 
-            if (adminMenu == null)
+            if (adminMenu is null)
             {
                 await _notifier.ErrorAsync(H["Can't find the admin menu."]);
                 return RedirectToAction(nameof(List));
@@ -284,7 +284,7 @@ public async Task<IActionResult> Toggle(string id)
             var adminMenuList = await _adminMenuService.LoadAdminMenuListAsync();
             var adminMenu = _adminMenuService.GetAdminMenuById(adminMenuList, id);
 
-            if (adminMenu == null)
+            if (adminMenu is null)
             {
                 return NotFound();
             }