[CodeIssue] Added DoubleNegationExpressionIssue

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

@@ -266,6 +266,7 @@
     <Compile Include="Refactoring\CodeIssues\BitwiseOperationOnNonFlagsEnumIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\CompareFloatWithEqualityOperatorIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ConstantConditionIssue.cs" />
+    <Compile Include="Refactoring\CodeIssues\DoubleNegationExpressionIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ExplicitConversionInForEachIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\ForControlVariableNotModifiedIssue.cs" />
     <Compile Include="Refactoring\CodeIssues\IdenticalConditionalBranchIssue.cs" />

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/DoubleNegationExpressionIssue.cs

@@ -0,0 +1,76 @@
+// 
+// DoubleNegationExpressionIssue.cs
+// 
+// Author:
+//      Mansheng Yang <lightyang0@gmail.com>
+// 
+// Copyright (c) 2012 Mansheng Yang <lightyang0@gmail.com>
+// 
+// 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 System.Collections.Generic;
+
+namespace ICSharpCode.NRefactory.CSharp.Refactoring
+{
+	[IssueDescription ("Simplify double negation expression",
+					   Description = "Simplify double negation expression",
+					   Category = IssueCategories.Improvements,
+					   Severity = Severity.Suggestion,
+					   IssueMarker = IssueMarker.Underline)]
+	public class DoubleNegationExpressionIssue : ICodeIssueProvider
+	{
+		public IEnumerable<CodeIssue> GetIssues (BaseRefactoringContext context)
+		{
+			return new GatherVisitor (context).GetIssues ();
+		}
+
+		class GatherVisitor : GatherVisitorBase
+		{
+			public GatherVisitor (BaseRefactoringContext ctx)
+				: base (ctx)
+			{
+			}
+
+			public override void VisitUnaryOperatorExpression (UnaryOperatorExpression unaryOperatorExpression)
+			{
+				base.VisitUnaryOperatorExpression (unaryOperatorExpression);
+
+				if (unaryOperatorExpression.Operator != UnaryOperatorType.Not)
+					return;
+
+				var expr = unaryOperatorExpression.Expression;
+				while (expr != null && expr is ParenthesizedExpression)
+					expr = ((ParenthesizedExpression)expr).Expression;
+
+				var binaryOperatorExpr = expr as BinaryOperatorExpression;
+				if (binaryOperatorExpr == null)
+					return;
+
+				var negatedOp = CSharpUtil.NegateRelationalOperator(binaryOperatorExpr.Operator);
+				if (negatedOp == BinaryOperatorType.Any)
+					return;
+
+				AddIssue (unaryOperatorExpression, ctx.TranslateString ("Simplify negative equality expression"),
+					script => script.Replace (unaryOperatorExpression,
+						new BinaryOperatorExpression (binaryOperatorExpr.Left.Clone (), negatedOp,
+					          	binaryOperatorExpr.Right.Clone ())));
+			}
+		}
+	}
+}

ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/DoubleNegationExpressionIssueTests.cs

@@ -0,0 +1,93 @@
+// 
+// NegativeEqualityExpressionIssueTests.cs
+// 
+// Author:
+//      Mansheng Yang <lightyang0@gmail.com>
+// 
+// Copyright (c) 2012 Mansheng Yang <lightyang0@gmail.com>
+// 
+// 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 NUnit.Framework;
+
+namespace ICSharpCode.NRefactory.CSharp.CodeIssues
+{
+	[TestFixture]
+	public class DoubleNegationExpressionIssueTests : InspectionActionTestBase
+	{
+
+		public void Test (string op, string negatedOp)
+		{
+			var input = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		var x = !(1 " + op + @" 2);
+	}
+}";
+			var output = @"
+class TestClass
+{
+	void TestMethod ()
+	{
+		var x = 1 " + negatedOp + @" 2;
+	}
+}";
+			Test<DoubleNegationExpressionIssue> (input, 1, output);
+		}
+
+		[Test]
+		public void TestEquality ()
+		{
+			Test ("==", "!=");
+		}
+
+		[Test]
+		public void TestInEquality ()
+		{
+			Test ("!=", "==");
+		}
+
+		[Test]
+		public void TestGreaterThan ()
+		{
+			Test (">", "<=");
+		}
+
+		[Test]
+		public void TestGreaterThanOrEqual ()
+		{
+			Test (">=", "<");
+		}
+
+		[Test]
+		public void TestLessThan ()
+		{
+			Test ("<", ">=");
+		}
+
+		[Test]
+		public void TestLessThanOrEqual ()
+		{
+			Test ("<=", ">");
+		}
+	}
+}

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

@@ -112,6 +112,7 @@
     <Compile Include="CSharp\CodeIssues\LocalVariableNotUsedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\LocalVariableOnlyAssignedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\MultipleEnumerationIssueTests.cs" />
+    <Compile Include="CSharp\CodeIssues\DoubleNegationExpressionIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\ParameterHidesMemberIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\ParameterNotUsedIssueTests.cs" />
     <Compile Include="CSharp\CodeIssues\ParameterOnlyAssignedIssueTests.cs" />