Add initial work on code analyzers

docs/docfx.json

@@ -27,7 +27,9 @@
         "files": [
           "concepts/**/*.md",
           "concepts/**/*.yml",
-	  "api/**/*.md",
+          "rules/**/*.md",
+          "rules/**/*.yml",
+          "api/**/*.md",
           "*.md",
           "toc.yml"
         ]

docs/rules/WinUIEx1001.md

@@ -0,0 +1,19 @@
+## WinUIEX1001: The member will always be null.
+
+The member will always be null and should not be used. This API was there due to UWP API surface area requirements, but is not needed for WinUI, and thus was never implemented.
+
+|Item|Value|
+|-|-|
+|Category|MicrosoftCodeAnalysisCorrectness|
+|Enabled|True|
+|Severity|Warning|
+|CodeFix|False|
+---
+
+One example is `Window.Current`: WinUI 3 does not have the notion of a current window. If you're interested in getting a reference to you main window, you could add a property to your `App` class that returns the main window, and set that property when you create the window.
+
+### References
+
+ - [Windows Runtime APIs not supported in desktop apps](https://learn.microsoft.com/en-us/windows/apps/desktop/modernize/desktop-to-uwp-supported-api)
+ - [Window.Current is null](https://github.com/microsoft/microsoft-ui-xaml/issues/4177)
+ - [Deprecate and hide from Intellisense APIs that always return null, like Window.Current](https://github.com/microsoft/WindowsAppSDK/issues/1660)

docs/rules/WinUIEx1002.md

@@ -0,0 +1,32 @@
+## WinUIEX1002: The member will always be null.
+
+The Dispatcher will always return null. It has been replaced by the DispatcherQueue. This API was there due to UWP API surface area requirements, but is not used in WinUI, and has been replaced by the DispatcherQueue.
+
+|Item|Value|
+|-|-|
+|Category|MicrosoftCodeAnalysisCorrectness|
+|Enabled|True|
+|Severity|Warning|
+|CodeFix|False|
+---
+
+### Example
+
+To address this, change your use of `Dispatcher` from:
+```cs
+Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
+{
+
+});
+```
+to:
+```cs
+DispatcherQueue.TryEnqueue(Microsoft.UI.Dispatching.DispatcherQueuePriority.Normal, () =>
+{
+});
+```
+
+### References
+ - [Windows Runtime APIs not supported in desktop apps](https://learn.microsoft.com/en-us/windows/apps/desktop/modernize/desktop-to-uwp-supported-api)
+ - [Remove DependencyObject.Dispatcher and Window.Dispatcher](https://github.com/microsoft/microsoft-ui-xaml/issues/6027) 
+ - [Dispatcher properties are now null](https://github.com/microsoft/microsoft-ui-xaml/issues/4164)

src/WinUIEx.Analyzers/WinUIEx.Analyzers.CodeFixes/CodeFixResources.resx

@@ -0,0 +1,124 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <data name="CodeFixTitle" xml:space="preserve">
+    <value>Fix use of Dispatcher</value>
+    <comment>The title of the code fix.</comment>
+  </data>
+</root>

src/WinUIEx.Analyzers/WinUIEx.Analyzers.CodeFixes/WinUIEx.Analyzers.CodeFixes.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <IsPackable>false</IsPackable>
+    <RootNamespace>WinUIEx.Analyzers</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.7.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\WinUIEx.Analyzers\WinUIEx.Analyzers.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="CodeFixResources.Designer.cs" DesignTime="True" AutoGen="True" DependentUpon="CodeFixResources.resx" />
+    <EmbeddedResource Update="CodeFixResources.resx" Generator="ResXFileCodeGenerator" LastGenOutput="CodeFixResources.Designer.cs" />
+  </ItemGroup>
+
+</Project>

src/WinUIEx.Analyzers/WinUIEx.Analyzers.CodeFixes/WinUIExAnalyzersCodeFixProvider.cs

@@ -0,0 +1,79 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Rename;
+using Microsoft.CodeAnalysis.Text;
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Composition;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace WinUIEx.Analyzers
+{
+    [ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(WinUIExAnalyzersCodeFixProvider)), Shared]
+    public class WinUIExAnalyzersCodeFixProvider : CodeFixProvider
+    {
+        public sealed override ImmutableArray<string> FixableDiagnosticIds
+        {
+            get { return ImmutableArray.Create(WinUIExAlwaysNullAnalyzer.DiagnosticId1002); }
+        }
+
+        public sealed override FixAllProvider GetFixAllProvider()
+        {
+            // See https://github.com/dotnet/roslyn/blob/main/docs/analyzers/FixAllProvider.md for more information on Fix All Providers
+            return WellKnownFixAllProviders.BatchFixer;
+        }
+
+        public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
+        {
+            var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+
+            // TODO: Replace the following code with your own analysis, generating a CodeAction for each fix to suggest
+            var diagnostic = context.Diagnostics.First();
+            var diagnosticSpan = diagnostic.Location.SourceSpan;
+
+            // Find the type declaration identified by the diagnostic.
+            var token = root.FindToken(diagnosticSpan.Start);
+            var root2 = token.SyntaxTree.GetRoot();
+
+            var properties = token.Parent.FirstAncestorOrSelf<PropertyDeclarationSyntax>();
+            var declaration = token.Parent.AncestorsAndSelf().OfType<TypeDeclarationSyntax>().First();
+
+            // Register a code action that will invoke the fix.
+            context.RegisterCodeFix(
+                CodeAction.Create(
+                    title: CodeFixResources.CodeFixTitle,
+                    createChangedSolution: 
+                    c => MakeUppercaseAsync(context.Document, declaration, c),
+                    // c =>
+                    // {
+                    //     document.po
+                    // }
+                    equivalenceKey: nameof(CodeFixResources.CodeFixTitle)),
+                diagnostic);
+        }
+
+        private async Task<Solution> MakeUppercaseAsync(Document document, TypeDeclarationSyntax typeDecl, CancellationToken cancellationToken)
+        {
+            // Compute new uppercase name.
+            var identifierToken = typeDecl.Identifier;
+
+            // Get the symbol representing the type to be renamed.
+            var semanticModel = await document.GetSemanticModelAsync(cancellationToken);
+            var typeSymbol = semanticModel.GetDeclaredSymbol(typeDecl, cancellationToken);
+
+            // Produce a new solution that has all references to that type renamed, including the declaration.
+            var originalSolution = document.Project.Solution;
+            var optionSet = originalSolution.Workspace.Options;
+            var newSolution = await Renamer.RenameSymbolAsync(document.Project.Solution, typeSymbol, "DispatcherQueue", optionSet, cancellationToken).ConfigureAwait(false);
+
+            // Return the new solution with the now-uppercase type name.
+            return newSolution;
+        }
+    }
+}