System.CodeDom.Tests.CSharpCodeGenerationTests.TryCatchThrow C# (CSharp) Method

        public void TryCatchThrow()
        {
            var cd = new CodeTypeDeclaration();
            cd.Name = "Test";
            cd.IsClass = true;

            // try catch statement with just finally
            var cmm = new CodeMemberMethod();
            cmm.Name = "FirstScenario";
            cmm.ReturnType = new CodeTypeReference(typeof(int));
            cmm.Attributes = MemberAttributes.Public | MemberAttributes.Static;
            CodeParameterDeclarationExpression param = new CodeParameterDeclarationExpression(typeof(int), "a");
            cmm.Parameters.Add(param);

            CodeTryCatchFinallyStatement tcfstmt = new CodeTryCatchFinallyStatement();
            tcfstmt.FinallyStatements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("a"), new
                                                                  CodeBinaryOperatorExpression(new CodeVariableReferenceExpression("a"), CodeBinaryOperatorType.Add,
                                                                                               new CodePrimitiveExpression(5))));
            cmm.Statements.Add(tcfstmt);
            cmm.Statements.Add(new CodeMethodReturnStatement(new CodeVariableReferenceExpression("a")));
            cd.Members.Add(cmm);

            CodeBinaryOperatorExpression cboExpression = new CodeBinaryOperatorExpression(new CodeVariableReferenceExpression("a"), CodeBinaryOperatorType.Divide, new CodeVariableReferenceExpression("a"));
            CodeAssignStatement assignStatement = new CodeAssignStatement(new CodeVariableReferenceExpression("a"), cboExpression);

            // try catch statement with just catch
            cmm = new CodeMemberMethod();
            cmm.Name = "SecondScenario";
            cmm.ReturnType = new CodeTypeReference(typeof(int));
            cmm.Attributes = MemberAttributes.Public | MemberAttributes.Static;
            param = new CodeParameterDeclarationExpression(typeof(int), "a");
            cmm.Parameters.Add(param);
            cmm.Parameters.Add(new CodeParameterDeclarationExpression(typeof(String), "exceptionMessage"));

            tcfstmt = new CodeTryCatchFinallyStatement();
            CodeCatchClause catchClause = new CodeCatchClause("e");
            tcfstmt.TryStatements.Add(assignStatement);
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("a"),
                                                               new CodePrimitiveExpression(3)));
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("exceptionMessage"),
                                                               new CodeMethodInvokeExpression(new CodeVariableReferenceExpression("e"), "ToString")));
            tcfstmt.CatchClauses.Add(catchClause);
            tcfstmt.FinallyStatements.Add(CreateVariableIncrementExpression("a", 1));

            cmm.Statements.Add(tcfstmt);
            cmm.Statements.Add(new CodeMethodReturnStatement(new CodeVariableReferenceExpression("a")));

            cd.Members.Add(cmm);

            // try catch statement with multiple catches
            cmm = new CodeMemberMethod();
            cmm.Name = "ThirdScenario";
            cmm.ReturnType = new CodeTypeReference(typeof(int));
            cmm.Attributes = MemberAttributes.Public | MemberAttributes.Static;
            param = new CodeParameterDeclarationExpression(typeof(int), "a");
            cmm.Parameters.Add(param);
            cmm.Parameters.Add(new CodeParameterDeclarationExpression(typeof(String), "exceptionMessage"));

            tcfstmt = new CodeTryCatchFinallyStatement();
            catchClause = new CodeCatchClause("e", new CodeTypeReference(typeof(ArgumentNullException)));
            tcfstmt.TryStatements.Add(assignStatement);
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("a"),
                                                               new CodePrimitiveExpression(9)));
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("exceptionMessage"),
                                                               new CodeMethodInvokeExpression(new CodeVariableReferenceExpression("e"), "ToString")));
            tcfstmt.CatchClauses.Add(catchClause);

            // add a second catch clause
            catchClause = new CodeCatchClause("f", new CodeTypeReference(typeof(Exception)));
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("exceptionMessage"),
                                                               new CodeMethodInvokeExpression(new CodeVariableReferenceExpression("f"), "ToString")));
            catchClause.Statements.Add(new CodeAssignStatement(new CodeVariableReferenceExpression("a"),
                                                               new CodePrimitiveExpression(9)));
            tcfstmt.CatchClauses.Add(catchClause);

            cmm.Statements.Add(tcfstmt);
            cmm.Statements.Add(new CodeMethodReturnStatement(new CodeVariableReferenceExpression("a")));
            cd.Members.Add(cmm);

            // catch throws exception
            cmm = new CodeMemberMethod();
            cmm.Name = "FourthScenario";
            cmm.ReturnType = new CodeTypeReference(typeof(int));
            cmm.Attributes = MemberAttributes.Public | MemberAttributes.Static;
            param = new CodeParameterDeclarationExpression(typeof(int), "a");
            cmm.Parameters.Add(param);

            tcfstmt = new CodeTryCatchFinallyStatement();
            catchClause = new CodeCatchClause("e");
            tcfstmt.TryStatements.Add(assignStatement);
            catchClause.Statements.Add(new CodeCommentStatement("Error handling"));
            catchClause.Statements.Add(new CodeThrowExceptionStatement(new CodeArgumentReferenceExpression("e")));
            tcfstmt.CatchClauses.Add(catchClause);
            cmm.Statements.Add(tcfstmt);
            cmm.Statements.Add(new CodeMethodReturnStatement(new CodeVariableReferenceExpression("a")));
            cd.Members.Add(cmm);

            AssertEqual(cd,
                @"public class Test {
                      public static int FirstScenario(int a) {
                          try {
                          }
                          finally {
                              a = (a + 5);
                          }
                          return a;
                      }
                      public static int SecondScenario(int a, string exceptionMessage) {
                          try {
                              a = (a / a);
                          }
                          catch (System.Exception e) {
                              a = 3;
                              exceptionMessage = e.ToString();
                          }
                          finally {
                              a = (a + 1);
                          }
                          return a;
                      }
                      public static int ThirdScenario(int a, string exceptionMessage) {
                          try {
                              a = (a / a);
                          }
                          catch (System.ArgumentNullException e) {
                              a = 9;
                              exceptionMessage = e.ToString();
                          }
                          catch (System.Exception f) {
                              exceptionMessage = f.ToString();
                              a = 9;
                          }
                          return a;
                      }
                      public static int FourthScenario(int a) {
                          try {
                              a = (a / a);
                          }
                          catch (System.Exception e) {
                              // Error handling
                              throw e;
                          }
                          return a;
                      }
                  }");
        }