Add RemoveRedundantCatchTypeAction.

ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj

@@ -373,6 +373,7 @@
     <Compile Include="Refactoring\CodeActions\ImplementInterfaceAction.cs" />
     <Compile Include="Refactoring\CodeActions\ImplementInterfaceExplicitAction.cs" />
     <Compile Include="Refactoring\CodeActions\ImplementAbstractMembersAction.cs" />
+    <Compile Include="Refactoring\CodeActions\RemoveRedundantCatchTypeAction.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/RemoveRedundantCatchTypeAction.cs

@@ -0,0 +1,92 @@
+//
+// RemoveRedundantCatchTypeAction.cs
+//
+// Author:
+//       Simon Lindgren <simon.n.lindgren@gmail.com>
+//
+// Copyright (c) 2012 Simon Lindgren
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using ICSharpCode.NRefactory.CSharp.Refactoring;
+using ICSharpCode.NRefactory.TypeSystem;
+using System;
+using ICSharpCode.NRefactory.Semantics;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{	
+	[ContextAction("Remove redundant type",
+	               Description = "Removes a redundant exception type specifier from catch clauses.")]
+	public class RemoveRedundantCatchTypeAction : ICodeActionProvider
+	{
+		#region ICodeActionProvider implementation
+		public System.Collections.Generic.IEnumerable<CodeAction> GetActions(RefactoringContext context)
+		{
+			var catchClause = context.GetNode<CatchClause>();
+			if (catchClause == null)
+				yield break;
+			if (catchClause.Type.IsNull)
+				yield break;
+			var exceptionType = context.ResolveType(catchClause.Type);
+			if (exceptionType != context.Compilation.FindType(typeof(Exception)))
+				yield break;
+			var exceptionIdentifierRR = context.Resolve(catchClause.VariableNameToken) as LocalResolveResult;
+			if (exceptionIdentifierRR != null &&
+				IsReferenced(exceptionIdentifierRR.Variable, catchClause.Body, context))
+				yield break;
+			yield return new CodeAction(context.TranslateString("Remove type specifier"), script => {
+				script.Replace(catchClause, new CatchClause() {
+					Body = catchClause.Body.Clone() as BlockStatement
+				});
+			});
+		}
+
+		bool IsReferenced(IVariable variable, AstNode node, RefactoringContext context)
+		{
+			var visitor = new ReferenceFinderVisitor(context, variable);
+			node.AcceptVisitor(visitor);
+			return visitor.FoundReference;
+		}
+
+		class ReferenceFinderVisitor: DepthFirstAstVisitor
+		{
+			RefactoringContext context;
+			IVariable variable;
+
+			public ReferenceFinderVisitor(RefactoringContext context, IVariable variable)
+			{
+				this.context = context;
+				this.variable = variable;
+			}
+
+			public bool FoundReference { get; private set; }
+
+			public override void VisitIdentifierExpression(IdentifierExpression identifierExpression)
+			{
+				var resolvedIdentifier = context.Resolve(identifierExpression) as LocalResolveResult;
+				if (resolvedIdentifier != null)
+					FoundReference |= resolvedIdentifier.Variable == variable;
+				base.VisitIdentifierExpression(identifierExpression);
+			}
+		}
+
+		#endregion
+	}
+}
+

ICSharpCode.NRefactory.Tests/CSharp/CodeActions/RemoveRedundantCatchTypeTests.cs

@@ -0,0 +1,108 @@
+//
+// RemoveRedundantCatchTypeTests.cs
+//
+// Author:
+//       Simon Lindgren <simon.n.lindgren@gmail.com>
+//
+// Copyright (c) 2012 Simon Lindgren
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using NUnit.Framework;
+using ICSharpCode.NRefactory.CSharp.Refactoring;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeActions
+{
+
+	[TestFixture]
+	public class RemoveRedundantCatchTypeTests : ContextActionTestBase
+	{
+		[Test]
+		public void RemovesSimpleExceptionMatch()
+		{
+			Test<RemoveRedundantCatchTypeAction>(@"
+class TestClass
+{
+	public void F()
+	{
+		try {
+		}
+		catch $(System.Exception) {
+		}
+	}
+}", @"
+class TestClass
+{
+	public void F()
+	{
+		try {
+		}
+		catch {
+		}
+	}
+}");
+		}
+
+		[Test]
+		public void PreservesBody()
+		{
+			Test<RemoveRedundantCatchTypeAction>(@"
+class TestClass
+{
+	public void F()
+	{
+		try {
+		}
+		catch $(System.Exception e) {
+			System.Console.WriteLine (""Hi"");
+		}
+	}
+}", @"
+class TestClass
+{
+	public void F()
+	{
+		try {
+		}
+		catch {
+			System.Console.WriteLine (""Hi"");
+		}
+	}
+}");
+		}
+
+		[Test]
+		public void IgnoresReferencedExceptionMatch()
+		{
+			TestWrongContext<RemoveRedundantCatchTypeAction>(@"
+class TestClass
+{
+	public void F()
+	{	
+		try {
+		}
+		catch $(System.Exception e) {
+			System.Console.WriteLine (e);
+		}
+	}
+}");
+		}
+	}
+}
+

ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj

@@ -269,6 +269,7 @@
     <Compile Include="CSharp\CodeActions\ImplementInterfaceTests.cs" />
     <Compile Include="CSharp\CodeActions\ImplementInterfaceExplicitTests.cs" />
     <Compile Include="CSharp\CodeActions\ImplementAbstractMembersTest.cs" />
+    <Compile Include="CSharp\CodeActions\RemoveRedundantCatchTypeTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\Mono.Cecil\Mono.Cecil.csproj">