Merge pull request #23 from sharwell/fix-15

Asynchronous interface checks

Author: sharwell

OpenStackNetAnalyzers/OpenStackNetAnalyzers/CancellationTokenAnalyzer.cs

@@ -0,0 +1,55 @@
+namespace OpenStackNetAnalyzers
+{
+    using System.Collections.Immutable;
+    using System.Linq;
+    using Microsoft.CodeAnalysis;
+    using Microsoft.CodeAnalysis.Diagnostics;
+
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public class CancellationTokenAnalyzer : DiagnosticAnalyzer
+    {
+        public const string DiagnosticId = "CancellationToken";
+        internal const string Title = "Asynchronous methods should accept a CancellationToken";
+        internal const string MessageFormat = "Asynchronous methods should accept a CancellationToken";
+        internal const string Category = "OpenStack.Maintainability";
+        internal const string Description = "Asynchronous methods should accept a CancellationToken";
+
+        private static DiagnosticDescriptor Descriptor =
+            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, Category, DiagnosticSeverity.Warning, isEnabledByDefault: true, description: Description);
+
+        private static readonly ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics =
+            ImmutableArray.Create(Descriptor);
+
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
+        {
+            get
+            {
+                return _supportedDiagnostics;
+            }
+        }
+
+        public override void Initialize(AnalysisContext context)
+        {
+            context.RegisterSymbolAction(HandleMethod, SymbolKind.Method);
+        }
+
+        private void HandleMethod(SymbolAnalysisContext context)
+        {
+            IMethodSymbol method = (IMethodSymbol)context.Symbol;
+            if (!method.Name.EndsWith("Async"))
+                return;
+
+            if (!method.ReturnType.IsTask())
+                return;
+
+            foreach (IParameterSymbol parameter in method.Parameters)
+            {
+                if (parameter.Type.IsCancellationToken())
+                    return;
+            }
+
+            ImmutableArray<Location> locations = method.Locations;
+            context.ReportDiagnostic(Diagnostic.Create(Descriptor, locations.FirstOrDefault(), locations.Skip(1)));
+        }
+    }
+}

OpenStackNetAnalyzers/OpenStackNetAnalyzers/OpenStackNetAnalyzers.csproj

@@ -33,6 +33,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="AssertNullAnalyzer.cs" />
+    <Compile Include="CancellationTokenAnalyzer.cs" />
     <Compile Include="DocumentationSyntaxExtensions.cs" />
     <Compile Include="DocumentDelegatingApiCallAnalyzer.cs" />
     <Compile Include="DocumentDelegatingApiCallCodeFix.cs" />
@@ -49,6 +50,8 @@
     <Compile Include="PlaceholderDocumentationCodeFix.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SdkTypeSymbolExtensions.cs" />
+    <Compile Include="ServiceMethodPrepareAsyncAnalyzer.cs" />
+    <Compile Include="ServiceMethodReturnValueAnalyzer.cs" />
     <Compile Include="SpacingExtensions.cs" />
     <Compile Include="TypeSymbolExtensions.cs" />
     <Compile Include="XmlSyntaxFactory.cs" />

OpenStackNetAnalyzers/OpenStackNetAnalyzers/SdkTypeSymbolExtensions.cs

@@ -9,6 +9,8 @@ internal static class SdkTypeSymbolExtensions
 
         private const string FullyQualifiedDelegatingHttpApiCallT = "global::OpenStack.Net.DelegatingHttpApiCall<T>";
 
+        private const string FullyQualifiedIHttpService = "global::OpenStack.Services.IHttpService";
+
         public static bool IsExtensibleJsonObject(this INamedTypeSymbol symbol)
         {
             while (symbol != null && symbol.SpecialType != SpecialType.System_Object)
@@ -39,5 +41,19 @@ public static bool IsDelegatingHttpApiCall(this INamedTypeSymbol symbol)
 
             return false;
         }
+
+        public static bool IsHttpServiceInterface(this INamedTypeSymbol symbol)
+        {
+            if (symbol == null || symbol.TypeKind != TypeKind.Interface)
+                return false;
+
+            foreach (INamedTypeSymbol interfaceType in symbol.AllInterfaces)
+            {
+                if (string.Equals(FullyQualifiedIHttpService, interfaceType.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat)))
+                    return true;
+            }
+
+            return false;
+        }
     }
 }

OpenStackNetAnalyzers/OpenStackNetAnalyzers/ServiceMethodPrepareAsyncAnalyzer.cs

@@ -0,0 +1,59 @@
+namespace OpenStackNetAnalyzers
+{
+    using System;
+    using System.Collections.Immutable;
+    using System.Linq;
+    using Microsoft.CodeAnalysis;
+    using Microsoft.CodeAnalysis.Diagnostics;
+
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public class ServiceMethodPrepareAsyncAnalyzer : DiagnosticAnalyzer
+    {
+        public const string DiagnosticId = "ServiceMethodPrepareAsync";
+        internal const string Title = "Service methods should be named Prepare{Name}Async";
+        internal const string MessageFormat = "Service methods should be named Prepare{Name}Async";
+        internal const string Category = "OpenStack.Maintainability";
+        internal const string Description = "Service methods should be named Prepare{Name}Async";
+
+        private static DiagnosticDescriptor Descriptor =
+            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, Category, DiagnosticSeverity.Warning, isEnabledByDefault: true, description: Description);
+
+        private static readonly ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics =
+            ImmutableArray.Create(Descriptor);
+
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
+        {
+            get
+            {
+                return _supportedDiagnostics;
+            }
+        }
+
+        public override void Initialize(AnalysisContext context)
+        {
+            context.RegisterSymbolAction(HandleNamedType, SymbolKind.NamedType);
+        }
+
+        private void HandleNamedType(SymbolAnalysisContext context)
+        {
+            INamedTypeSymbol symbol = (INamedTypeSymbol)context.Symbol;
+            if (!symbol.IsHttpServiceInterface())
+                return;
+
+            foreach (IMethodSymbol method in symbol.GetMembers().OfType<IMethodSymbol>())
+            {
+                if (string.IsNullOrEmpty(method.Name))
+                    continue;
+
+                if (method.Name.StartsWith("Prepare", StringComparison.Ordinal) && method.Name.EndsWith("Async", StringComparison.Ordinal))
+                {
+                    // TODO check letter following 'Prepare'
+                    continue;
+                }
+
+                ImmutableArray<Location> locations = method.Locations;
+                context.ReportDiagnostic(Diagnostic.Create(Descriptor, locations.FirstOrDefault(), locations.Skip(1)));
+            }
+        }
+    }
+}

OpenStackNetAnalyzers/OpenStackNetAnalyzers/ServiceMethodReturnValueAnalyzer.cs

@@ -0,0 +1,60 @@
+namespace OpenStackNetAnalyzers
+{
+    using System.Collections.Immutable;
+    using System.Linq;
+    using Microsoft.CodeAnalysis;
+    using Microsoft.CodeAnalysis.Diagnostics;
+
+    [DiagnosticAnalyzer(LanguageNames.CSharp)]
+    public class ServiceMethodReturnValueAnalyzer : DiagnosticAnalyzer
+    {
+        public const string DiagnosticId = "ServiceMethodReturnValue";
+        internal const string Title = "Service interface methods should return a Task<T> with a result that implements IHttpApiCall<T>";
+        internal const string MessageFormat = "Service interface methods should return a Task<T> with a result that implements IHttpApiCall<T>";
+        internal const string Category = "OpenStack.Maintainability";
+        internal const string Description = "Service interface methods should return a Task<T> with a result that implements IHttpApiCall<T>";
+
+        private static DiagnosticDescriptor Descriptor =
+            new DiagnosticDescriptor(DiagnosticId, Title, MessageFormat, Category, DiagnosticSeverity.Warning, isEnabledByDefault: true, description: Description);
+
+        private static readonly ImmutableArray<DiagnosticDescriptor> _supportedDiagnostics =
+            ImmutableArray.Create(Descriptor);
+
+        public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
+        {
+            get
+            {
+                return _supportedDiagnostics;
+            }
+        }
+
+        public override void Initialize(AnalysisContext context)
+        {
+            context.RegisterSymbolAction(HandleNamedType, SymbolKind.NamedType);
+        }
+
+        private void HandleNamedType(SymbolAnalysisContext context)
+        {
+            INamedTypeSymbol symbol = (INamedTypeSymbol)context.Symbol;
+            if (!symbol.IsHttpServiceInterface())
+                return;
+
+            foreach (IMethodSymbol method in symbol.GetMembers().OfType<IMethodSymbol>())
+            {
+                INamedTypeSymbol returnType = method.ReturnType as INamedTypeSymbol;
+                if (returnType.IsTask() && returnType.IsGenericType && returnType.TypeArguments.Length == 1)
+                {
+                    INamedTypeSymbol genericArgument = returnType.TypeArguments[0] as INamedTypeSymbol;
+                    if (genericArgument.IsDelegatingHttpApiCall())
+                    {
+                        // the method returns the expected type
+                        continue;
+                    }
+                }
+
+                ImmutableArray<Location> locations = method.Locations;
+                context.ReportDiagnostic(Diagnostic.Create(Descriptor, locations.FirstOrDefault(), locations.Skip(1)));
+            }
+        }
+    }
+}

OpenStackNetAnalyzers/OpenStackNetAnalyzers/TypeSymbolExtensions.cs

@@ -7,6 +7,10 @@ internal static class TypeSymbolExtensions
     {
         private const string FullyQualifiedImmutableArrayT = "global::System.Collections.Immutable.ImmutableArray<T>";
 
+        private const string FullyQualifiedTask = "global::System.Threading.Tasks.Task";
+
+        private const string FullyQualifiedCancellationToken = "global::System.Threading.CancellationToken";
+
         public static bool IsNonNullableValueType(this ITypeSymbol type)
         {
             if (type == null)
@@ -47,5 +51,34 @@ public static bool IsImmutableArray(this ITypeSymbol type)
 
             return string.Equals(FullyQualifiedImmutableArrayT, originalDefinition.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat), StringComparison.Ordinal);
         }
+
+        public static bool IsTask(this ITypeSymbol symbol)
+        {
+            INamedTypeSymbol namedSymbol = symbol as INamedTypeSymbol;
+            while (namedSymbol != null && namedSymbol.SpecialType != SpecialType.System_Object)
+            {
+                if (!namedSymbol.IsGenericType)
+                {
+                    if (string.Equals(FullyQualifiedTask, namedSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat), StringComparison.Ordinal))
+                        return true;
+                }
+
+                namedSymbol = namedSymbol.BaseType;
+            }
+
+            return false;
+        }
+
+        public static bool IsCancellationToken(this ITypeSymbol symbol)
+        {
+            INamedTypeSymbol namedSymbol = symbol as INamedTypeSymbol;
+            if (namedSymbol == null)
+                return false;
+
+            if (namedSymbol.TypeKind != TypeKind.Struct)
+                return false;
+
+            return string.Equals(FullyQualifiedCancellationToken, namedSymbol.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat), StringComparison.Ordinal);
+        }
     }
 }