Flatting complex model (#13)

* Add Flatting Complex diagnostic with tests

* Add fix with tests

* Update README

Author: Scogun

README.md

@@ -38,7 +38,7 @@ The project already contains:
 	</tr>
 	<tr>
 		<td rowspan="7">Common smells</td>
-		<td rowspan="5">Available</td>
+		<td rowspan="6">Available</td>
 		<td><b>AMA0001</b></td>
 		<td rowspan="7">Warrning</td>
 		<td>Profile doesn't contain maps</td>
@@ -54,6 +54,11 @@ The project already contains:
 		<td>Manual checking that src is not null</td>
 		<td>Available for next checking: "??", "== null", "!= null"</td>
 	</tr>
+	<tr>		
+		<td><b>AMA0005</b></td>
+		<td>Manual flattening of complex model</td>
+		<td>Available</td>
+	</tr>
 	<tr>		
 		<td><b>AMA0006</b></td>
 		<td>Manual flattening of naming similar complex model</td>
@@ -65,16 +70,11 @@ The project already contains:
 		<td>Available</td>
 	</tr>
 	<tr>
-        <td rowspan="2">In Plans</td>
+        <td>In Plans</td>
 		<td><b>AMA0004</b></td>
 		<td>ForMember ignore for all left properties</td>
 		<td>...</td>
 	</tr>
-	<tr>		
-		<td><b>AMA0005</b></td>
-		<td>Manual flattening of complex model</td>
-		<td>...</td>
-	</tr>
 </table>
 
 ## Installation

src/AutoMapper.Analyzers.Common.CodeFixes/FlattingComplexModelCodeFixProvider.cs

@@ -0,0 +1,86 @@
+using System.Collections.Immutable;
+using System.Composition;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Text;
+
+namespace AutoMapper.Analyzers.Common;
+
+[ExportCodeFixProvider(LanguageNames.CSharp, Name = nameof(FlattingComplexModelCodeFixProvider)), Shared]
+public class FlattingComplexModelCodeFixProvider : CodeFixProvider
+{
+    public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(FlattingComplexModelAnalyzer.DiagnosticId);
+
+    public override FixAllProvider GetFixAllProvider() => WellKnownFixAllProviders.BatchFixer;
+
+    public override async Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
+
+        var diagnostic = context.Diagnostics.First();
+        var diagnosticSpans = new List<TextSpan> { diagnostic.Location.SourceSpan };
+        diagnosticSpans.AddRange(diagnostic.AdditionalLocations.Select(al => al.SourceSpan));
+
+        var declarations = diagnosticSpans.Select(s =>
+            root.FindToken(s.Start).Parent.Ancestors().OfType<InvocationExpressionSyntax>().First());
+
+        context.RegisterCodeFix(
+            CodeAction.Create("Replace manual complex flatting by IncludeMembers call",
+                c => UseIncludeMembers(context.Document, declarations, c), "FlattingComplexModelFixTitle"), diagnostic);
+    }
+
+    private async Task<Document> UseIncludeMembers(Document document,
+        IEnumerable<InvocationExpressionSyntax> declarations, CancellationToken cancellationToken)
+    {
+        var syntaxRoot = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
+        syntaxRoot = syntaxRoot.ReplaceNodes(declarations.Select(d => syntaxRoot.FindNode(d.Span)),
+            (_, syntaxNode) => syntaxNode.DescendantNodes().OfType<InvocationExpressionSyntax>().FirstOrDefault());
+
+        var lambda = BuildLambdaExpression(declarations);
+        var includeMembers = GetIncludeMembersInvocation(declarations, ref syntaxRoot);
+
+        var argumentList = new List<ArgumentSyntax>(includeMembers.ArgumentList.Arguments) { SyntaxFactory.Argument(lambda) };
+
+        var includeCall = SyntaxFactory.InvocationExpression(includeMembers.Expression,
+            SyntaxFactory.ArgumentList(SyntaxFactory.SeparatedList(argumentList)));
+
+        return document.WithSyntaxRoot(syntaxRoot.ReplaceNode(includeMembers, includeCall).NormalizeWhitespace());
+    }
+
+    private InvocationExpressionSyntax GetIncludeMembersInvocation(IEnumerable<InvocationExpressionSyntax> declarations, ref SyntaxNode? syntaxRoot)
+    {
+        var invocationExpressions = syntaxRoot.FindToken(declarations.ElementAt(0).SpanStart).Parent.Ancestors().OfType<InvocationExpressionSyntax>();
+        var includeMembersName = nameof(IMappingExpression.IncludeMembers);
+        var includeMembers = invocationExpressions.FirstOrDefault(i => i.ToString().Contains(includeMembersName));
+        if (includeMembers == null)
+        {
+            SyntaxNode createMap = invocationExpressions.Where(i => i.Expression is GenericNameSyntax).FirstOrDefault(i => i.ToString().StartsWith(nameof(Profile.CreateMap)));
+            var newCreateMapString = createMap.Parent.ToFullString().Replace(createMap.ToFullString().Trim(),$"{createMap.ToFullString()}.{includeMembersName}()");
+            var newCreateMap = SyntaxFactory.ParseExpression(newCreateMapString);
+            if (createMap.Parent is MemberAccessExpressionSyntax)
+            {
+                createMap = createMap.Parent;
+            }
+            syntaxRoot = syntaxRoot.ReplaceNode(createMap, newCreateMap);
+            includeMembers = syntaxRoot.FindToken(declarations.ElementAt(0).SpanStart).Parent.Ancestors().OfType<InvocationExpressionSyntax>()
+                .First(i => i.ToString().Contains(includeMembersName));
+        }
+
+        return includeMembers;
+    }
+
+    private static SimpleLambdaExpressionSyntax BuildLambdaExpression(IEnumerable<InvocationExpressionSyntax> declarations)
+    {
+        var srcProperty =
+            ForMemberAnalyzer.GetLambdaExpressions(declarations.ElementAt(0)).srcExpression as SimpleLambdaExpressionSyntax;
+        var srcCall = srcProperty.ExpressionBody.ToFullString();
+        srcCall = srcCall.Substring(0, srcCall.LastIndexOf('.'));
+        var srcName = srcProperty.Parameter.Identifier.Text;
+
+        return SyntaxFactory.SimpleLambdaExpression(SyntaxFactory.Parameter(SyntaxFactory.ParseToken(srcName)),
+            SyntaxFactory.ParseExpression(srcCall));
+    }
+}

src/AutoMapper.Analyzers.Common.CodeFixes/NullSubstituteCodeFixProvider.cs

@@ -75,7 +75,7 @@ private bool IsComplexMapping(InvocationExpressionSyntax invocation, out string
         srcProperty = string.Empty;
 
         var syntaxNode = invocation.DescendantNodes()
-            .FirstOrDefault(n => n is ConditionalExpressionSyntax || n is BinaryExpressionSyntax);
+            .FirstOrDefault(n => n is ConditionalExpressionSyntax or BinaryExpressionSyntax);
         if (syntaxNode is ConditionalExpressionSyntax { Condition: BinaryExpressionSyntax binaryCondition } conditional)
         {
             var srcMember = binaryCondition.Left.ToString();

src/AutoMapper.Analyzers.Common/FlattingComplexModelAnalyzer.cs

@@ -0,0 +1,53 @@
+using System.Linq;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace AutoMapper.Analyzers.Common;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public class FlattingComplexModelAnalyzer : ForMemberAnalyzer
+{
+    public const string DiagnosticId = "AMA0005";
+
+    protected override string InternalDiagnosticId => DiagnosticId;
+    
+    protected override Diagnostic AnalyzeMapFrom(LambdaExpressionSyntax destExpression,
+            LambdaExpressionSyntax srcExpression)
+        {
+            if (TryGetExpressionMemberName(srcExpression, out IdentifierNameSyntax srcName) &&
+                TryGetExpressionMemberName(destExpression, out string destName) &&
+                srcName.ToString().Equals(destName) && srcName.Parent is MemberAccessExpressionSyntax srcMember)
+            {
+                var srcMemberCall = srcMember.Expression.ToFullString();
+                var nextMembers = ForMember.DescendantNodes().OfType<InvocationExpressionSyntax>().Where(IsForMember).ToList();
+                var prevMembers = ForMember.Ancestors().OfType<InvocationExpressionSyntax>().Where(IsForMember);
+                if (!prevMembers.Any(s => IsSameComplexFlatting(s, srcMemberCall)) &&
+                    nextMembers.Any(s => IsSameComplexFlatting(s, srcMemberCall)))
+                {
+                    return Diagnostic.Create(Rule, ForMember.ArgumentList.GetLocation(), nextMembers.Select(m => m.ArgumentList.GetLocation()).ToList(),ProfileName, MapName);
+                }
+            }
+
+            return base.AnalyzeMapFrom(destExpression, srcExpression);
+        }
+
+        private bool IsSameComplexFlatting(InvocationExpressionSyntax syntax, string smelledMemberCall) =>
+            TryGetExpressionMemberName(GetLambdaExpressions(syntax).srcExpression,
+                out IdentifierNameSyntax srcSyntax)
+            && srcSyntax.Parent is MemberAccessExpressionSyntax srcAccess &&
+            srcAccess.Expression.ToFullString().Equals(smelledMemberCall);
+
+        private bool IsForMember(InvocationExpressionSyntax syntax)
+        {
+            if (syntax.Expression is MemberAccessExpressionSyntax memberAccess && memberAccess.Name.Identifier.Text.Equals(nameof(IMappingExpression.ForMember)))
+            {
+                var (descExpression, srcExpression) = GetLambdaExpressions(syntax);
+                return TryGetExpressionMemberName(descExpression, out string destName) &&
+                       TryGetExpressionMemberName(srcExpression, out string srcName)
+                       && destName.Equals(srcName);
+            }
+
+            return false;
+        }
+}

src/AutoMapper.Analyzers.Common/ForMemberAnalyzer.cs

@@ -29,7 +29,7 @@ protected override Diagnostic AnalyzeInvocationOperation(IInvocationOperation in
         return base.AnalyzeInvocationOperation(invocationOperation);
     }
 
-    protected (LambdaExpressionSyntax descExpression, LambdaExpressionSyntax srcExpression) GetLambdaExpressions(InvocationExpressionSyntax forMember)
+    public static (LambdaExpressionSyntax descExpression, LambdaExpressionSyntax srcExpression) GetLambdaExpressions(InvocationExpressionSyntax forMember)
     {
         var destExpression = forMember.ArgumentList.Arguments[0].Expression as LambdaExpressionSyntax;
         var optExpression = forMember.ArgumentList.Arguments[1].Expression as LambdaExpressionSyntax;