Fix #119: LocalVariableOnlyAssignedIssue does not recognize usage through unary operator expression

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/VariableOnlyAssignedIssues/LocalVariableOnlyAssignedIssue.cs

@@ -30,7 +30,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 {
 
 	[IssueDescription ("Local variable is only assigned",
-					   Description = "Local variable is assigned by its value is never used",
+					   Description = "Local variable is assigned but its value is never used",
 					   Category = IssueCategories.CodeQualityIssues,
 					   Severity = Severity.Warning,
 					   IssueMarker = IssueMarker.Underline)]
@@ -62,7 +62,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 				if (!TestOnlyAssigned (ctx, decl.Parent, resolveResult.Variable))
 					return;
 				AddIssue (variableInitializer.NameToken,
-					ctx.TranslateString ("Local variable is assigned by its value is never used"));
+					ctx.TranslateString ("Local variable is assigned but its value is never used"));
 			}
 		}
 	}

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/VariableOnlyAssignedIssues/ParameterOnlyAssignedIssue.cs

@@ -28,7 +28,7 @@ using ICSharpCode.NRefactory.Semantics;
 namespace ICSharpCode.NRefactory.CSharp.Refactoring
 {
 	[IssueDescription ("Parameter is only assigned",
-					   Description = "Parameter is assigned by its value is never used.",
+					   Description = "Parameter is assigned but its value is never used.",
 					   Category = IssueCategories.CodeQualityIssues,
 					   Severity = Severity.Warning,
 					   IssueMarker = IssueMarker.Underline)]
@@ -60,7 +60,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					return;
 				}
 				AddIssue(parameterDeclaration.NameToken, 
-					ctx.TranslateString("Parameter is assigned by its value is never used"));
+					ctx.TranslateString("Parameter is assigned but its value is never used"));
 			}
 		}
 	}

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/VariableOnlyAssignedIssues/VariableOnlyAssignedIssue.cs

@@ -66,11 +66,16 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 							case UnaryOperatorType.Decrement:
 							case UnaryOperatorType.PostDecrement:
 								assignment = true;
+								if (!(parent.Parent is ExpressionStatement))
+									nonAssignment = true;
 								continue;
 						}
 					} else if (parent is DirectionExpression) {
 						if (((DirectionExpression)parent).FieldDirection == FieldDirection.Out) {
 							assignment = true;
+							// Using dummy variables is necessary for ignoring
+							// out-arguments, so we don't want to warn for those.
+							nonAssignment = true;
 							continue;
 						}
 					}

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

@@ -85,13 +85,29 @@ class TestClass
 	{
 		i = 1;
 	}
+	void TestMethod()
+	{
+		int tmp;
+		Test (out tmp);
+	}
+}";
+			// should not warn because ignoring out-arguments is legitimate
+			Test<LocalVariableOnlyAssignedIssue> (input1, 0);
+		}
+		
+		[Test]
+		public void TestIncrement ()
+		{
+			var input1 = @"
+class TestClass
+{
 	void TestMethod()
 	{
 		int i = 1;
-		Test (out i);
+		Test (i++);
 	}
 }";
-			Test<LocalVariableOnlyAssignedIssue> (input1, 1);
+			Test<LocalVariableOnlyAssignedIssue> (input1, 0);
 		}
 	}
 }