/src/NUnit/core/ExpectedExceptionProcessor.cs

// ****************************************************************

// Copyright 2008, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org.

// ****************************************************************



using System;

using System.Reflection;

using System.Text.RegularExpressions;



namespace NUnit.Core

{

    public class ExpectedExceptionProcessor

    {

        #region Fields

        /// <summary>

        /// The TestMethod to which this exception processor applies

        /// </summary>

        internal TestMethod testMethod;



        /// <summary>

        /// The exception handler method

        /// </summary>

        internal MethodInfo exceptionHandler;



        /// <summary>

        /// The type of any expected exception

        /// </summary>

        internal Type expectedExceptionType;



        /// <summary>

        /// The full name of any expected exception type

        /// </summary>

        internal string expectedExceptionName;



        /// <summary>

        /// The value of any message associated with an expected exception

        /// </summary>

        internal string expectedMessage;



        /// <summary>

        /// A string indicating how to match the expected message

        /// </summary>

        internal string matchType;



        /// <summary>

        /// A string containing any user message specified for the expected exception

        /// </summary>

        internal string userMessage;

        #endregion



        #region Constructor

        public ExpectedExceptionProcessor( TestMethod testMethod )

        {

            this.testMethod = testMethod;

        }



        public ExpectedExceptionProcessor(TestMethod testMethod, object source)

        {

            this.testMethod = testMethod;



            this.expectedExceptionType = GetExceptionType(source);

            this.expectedExceptionName = GetExceptionName(source);

            this.expectedMessage = GetExpectedMessage(source);

            this.matchType = GetMatchType(source);

            this.userMessage = GetUserMessage(source);



            string handlerName = GetHandler(source);

            if (handlerName == null)

                this.exceptionHandler = GetDefaultExceptionHandler(testMethod.FixtureType);

            else

            {

                MethodInfo handler = GetExceptionHandler(testMethod.FixtureType, handlerName);

                if (handler != null)

                    this.exceptionHandler = handler;

                else

                {

                    testMethod.RunState = RunState.NotRunnable;

                    testMethod.IgnoreReason = string.Format(

                        "The specified exception handler {0} was not found", handlerName);

                }

            }

        }

        #endregion



        #region Public Methods

        public void ProcessNoException(TestResult testResult)

        {

            testResult.Failure(NoExceptionMessage(), null);

        }



        public void ProcessException(Exception exception, TestResult testResult)

        {

            if (exception is NUnitException)

                exception = exception.InnerException;



            if (IsExpectedExceptionType(exception))

            {

                if (IsExpectedMessageMatch(exception))

                {

                    if (exceptionHandler != null)

                        Reflect.InvokeMethod(exceptionHandler, testMethod.Fixture, exception);



                    testResult.Success();

                }

                else

                {

                    testResult.Failure(WrongTextMessage(exception), GetStackTrace(exception));

                }

            }

            else

            {

                switch (NUnitFramework.GetResultState(exception))

                {

                    case ResultState.Failure:

                        testResult.Failure(exception.Message, exception.StackTrace);

                        break;

                    case ResultState.Ignored:

                        testResult.Ignore(exception);

                        break;

                    case ResultState.Inconclusive:

                        testResult.SetResult(ResultState.Inconclusive, exception, FailureSite.Test);

                        break;

                    case ResultState.Success:

                        testResult.Success(exception.Message);

                        break;

                    default:

                        testResult.Failure(WrongTypeMessage(exception), GetStackTrace(exception));

                        break;

                }

            }

		}

        #endregion



        #region Helper Methods

        private bool IsExpectedExceptionType(Exception exception)

        {

            return expectedExceptionName == null ||

                expectedExceptionName.Equals(exception.GetType().FullName);

        }



        private bool IsExpectedMessageMatch(Exception exception)

        {

            if (expectedMessage == null)

                return true;



            switch (matchType)

            {

                case "Exact":

                default:

                    return expectedMessage.Equals(exception.Message);

                case "Contains":

                    return exception.Message.IndexOf(expectedMessage) >= 0;

                case "Regex":

                    return Regex.IsMatch(exception.Message, expectedMessage);

                case "StartsWith":

                    return exception.Message.StartsWith(expectedMessage);

            }

        }



        private string NoExceptionMessage()

        {

            string expectedType = expectedExceptionName == null ? "An Exception" : expectedExceptionName;

            return CombineWithUserMessage(expectedType + " was expected");

        }



        private string WrongTypeMessage(Exception exception)

        {

            return CombineWithUserMessage(

                "An unexpected exception type was thrown" + Environment.NewLine +

                "Expected: " + expectedExceptionName + Environment.NewLine +

                " but was: " + exception.GetType().FullName + " : " + exception.Message);

        }



        private string WrongTextMessage(Exception exception)

        {

            string expectedText;

            switch (matchType)

            {

                default:

                case "Exact":

                    expectedText = "Expected: ";

                    break;

                case "Contains":

                    expectedText = "Expected message containing: ";

                    break;

                case "Regex":

                    expectedText = "Expected message matching: ";

                    break;

                case "StartsWith":

                    expectedText = "Expected message starting: ";

                    break;

            }



            return CombineWithUserMessage(

                "The exception message text was incorrect" + Environment.NewLine +

                expectedText + expectedMessage + Environment.NewLine +

                " but was: " + exception.Message);

        }



        private string CombineWithUserMessage(string message)

        {

            if (userMessage == null)

                return message;

            return userMessage + Environment.NewLine + message;

        }



        private string GetStackTrace(Exception exception)

        {

            try

            {

                return exception.StackTrace;

            }

            catch (Exception)

            {

                return "No stack trace available";

            }

        }



        private static MethodInfo GetDefaultExceptionHandler(Type fixtureType)

        {

            return Reflect.HasInterface(fixtureType, NUnitFramework.ExpectExceptionInterface)

                ? GetExceptionHandler(fixtureType, "HandleException")

                : null;

        }



        private static MethodInfo GetExceptionHandler(Type fixtureType, string name)

        {

            return Reflect.GetNamedMethod(

                fixtureType,

                name,

                new string[] { "System.Exception" });

        }



        private static string GetHandler(object source)

        {

            return Reflect.GetPropertyValue(source, "Handler") as string;

        }



        private static Type GetExceptionType(object source)

        {

            Type type = Reflect.GetPropertyValue(source, PropertyNames.ExpectedException) as Type;



            // Prior to 2.5, NUnit used an 'ExceptionType' property

            if (type == null)

                type = Reflect.GetPropertyValue(source, PropertyNames.LegacyExceptionType) as Type;



            return type;

        }



        private static string GetExceptionName(object source)

        {

            string name = Reflect.GetPropertyValue(source, PropertyNames.ExpectedExceptionName) as string;



            // Prior to 2.5, NUnit used an 'ExceptionName' property

            if (name == null)

                name = Reflect.GetPropertyValue(source, PropertyNames.LegacyExceptionName) as string;



            return name;

        }



        private static string GetExpectedMessage(object source)

        {

            return Reflect.GetPropertyValue(source, PropertyNames.ExpectedMessage) as string;

        }



        private static string GetMatchType(object source)

        {

            object matchEnum = Reflect.GetPropertyValue(source, "MatchType");

            return matchEnum != null ? matchEnum.ToString() : null;

        }



        private static string GetUserMessage(object source)

        {

            return Reflect.GetPropertyValue(source, "UserMessage") as string;

        }

        #endregion

    }

}