handle slim exceptions

.gitignore

@@ -7,4 +7,4 @@ bin/
 obj/
 TestResult.xml
 *.cache
-*.bat
+fitnesse*.cmd

source/fitnesse/fitnesse.csproj

@@ -43,6 +43,7 @@
     <Compile Include="slim\Messenger.cs" />
     <Compile Include="slim\operators\ComposeBoolean.cs" />
     <Compile Include="slim\operators\ComposeDefault.cs" />
+    <Compile Include="slim\operators\ComposeException.cs" />
     <Compile Include="slim\operators\ComposeList.cs" />
     <Compile Include="slim\operators\ExecuteBase.cs" />
     <Compile Include="slim\operators\ExecuteCall.cs" />

source/fitnesse/slim/Service.cs

@@ -21,6 +21,7 @@ public class Service: Processor<string> {
             AddOperator(new ParseList());
             AddOperator(new ParseSymbol(), 1);
             AddOperator(new ComposeDefault());
+            AddOperator(new ComposeException());
             AddOperator(new ComposeBoolean());
             AddOperator(new ComposeList());
         }

source/fitnesse/slim/operators/ComposeException.cs

@@ -0,0 +1,41 @@
+// Copyright © Syterra Software Inc. All rights reserved.
+// The use and distribution terms for this software are covered by the Common Public License 1.0 (http://opensource.org/licenses/cpl.php)
+// which can be found in the file license.txt at the root of this distribution. By using this software in any fashion, you are agreeing
+// to be bound by the terms of this license. You must not remove this notice, or any other, from this software.
+
+using System;
+using fitnesse.mtee.engine;
+using fitnesse.mtee.exception;
+using fitnesse.mtee.model;
+
+namespace fitnesse.slim.operators {
+    public class ComposeException: ComposeOperator<string> {
+        private const string ExceptionResult = "__EXCEPTION__:{0}";
+
+        public bool TryCompose(Processor<string> processor, TypedValue instance, ref Tree<string> result) {
+            if (!typeof(Exception).IsAssignableFrom(instance.Type)) return false;
+
+            if (TryResult<MemberException>(instance,
+                e => string.Format("NO_METHOD_IN_CLASS {0} {1}", e.MemberName, e.Type), ref result)) return true;
+
+            if (TryResult<ConstructorException>(instance,
+                e => string.Format("NO_CONSTRUCTOR {0}", e.Type), ref result)) return true;
+
+            result = MakeResult(instance.Value.ToString());
+            return true;
+        }
+
+        private delegate string Format<T>(T exception);
+
+        private static bool TryResult<T>(TypedValue exception, Format<T> formatter, ref Tree<string> result) where T: class {
+            var candidateException = exception.Value as T;
+            if (candidateException == null) return false;
+            result = MakeResult(string.Format("message<<{0}>> {1}", formatter(candidateException), candidateException));
+            return true;
+        }
+
+        private static Tree<string> MakeResult(string message) {
+            return new TreeLeaf<string>(string.Format(ExceptionResult, message));
+        }
+    }
+}

source/fitnesse/slim/operators/ExecuteBase.cs

@@ -10,7 +10,6 @@
 namespace fitnesse.slim.operators {
     public abstract class ExecuteBase: ExecuteOperator<string> {
         private const string defaultResult = "OK";
-        private const string ExceptionResult = "__EXCEPTION__:{0}";
         private readonly IdentifierName identifier;
 
         public bool TryExecute(Processor<string> processor, TypedValue instance, Tree<string> parameters, ref TypedValue result) {
@@ -19,7 +18,7 @@ public abstract class ExecuteBase: ExecuteOperator<string> {
                 result = new TypedValue(ExecuteOperation(processor, parameters));
             }
             catch (Exception e) {
-                result = new TypedValue(Result(parameters, string.Format(ExceptionResult, e)));
+                result = new TypedValue(Result(parameters, processor.Compose(e)));
             }
             return true;
         }

source/mtee/Engine/RuntimeType.cs

@@ -23,15 +23,13 @@ public class RuntimeType {
 
         public static RuntimeMember GetInstance(TypedValue instance, string memberName, int parameterCount) {
             RuntimeMember runtimeMember = FindInstance(instance.Value, memberName, parameterCount);
-            if (runtimeMember == null) throw new MemberException(
-                    string.Format("Member '{0}' with {1} parameter(s) not found for type '{2}'.", memberName, parameterCount, instance.Type.FullName));
+            if (runtimeMember == null) throw new MemberException(instance.Type, memberName, parameterCount);
             return runtimeMember;
         }
 
         public RuntimeMember GetConstructor(int parameterCount) {
             RuntimeMember runtimeMember = FindInstance(Type, ".ctor", parameterCount);
-            if (runtimeMember == null) throw new MemberException(
-                    string.Format("Constructor with {0} parameter(s) not found for type '{1}'.", parameterCount, Type.FullName));
+            if (runtimeMember == null) throw new ConstructorException(Type, parameterCount);
             return runtimeMember;
         }
 

source/mtee/exception/ConstructorException.cs

@@ -0,0 +1,19 @@
+// Copyright © Syterra Software Inc. All rights reserved.
+// The use and distribution terms for this software are covered by the Common Public License 1.0 (http://opensource.org/licenses/cpl.php)
+// which can be found in the file license.txt at the root of this distribution. By using this software in any fashion, you are agreeing
+// to be bound by the terms of this license. You must not remove this notice, or any other, from this software.
+
+using System;
+
+namespace fitnesse.mtee.exception {
+    public class ConstructorException: ApplicationException {
+        public Type Type { get; private set; }
+        public int ParameterCount { get; private set; }
+
+        public ConstructorException(Type type, int parameterCount)
+            : base(string.Format("Constructor with {1} parameter(s) not found for type '{0}'.", type.FullName, parameterCount)) {
+            Type = type;
+            ParameterCount = parameterCount;
+        }
+    }
+}

source/mtee/exception/MemberException.cs

@@ -7,6 +7,15 @@
 
 namespace fitnesse.mtee.exception {
     public class MemberException: ApplicationException {
-        public MemberException(string message): base(message) {}
+        public Type Type { get; private set; }
+        public string MemberName { get; private set; }
+        public int ParameterCount { get; private set; }
+
+        public MemberException(Type type, string memberName, int parameterCount)
+            : base(string.Format("Member '{1}' with {2} parameter(s) not found for type '{0}'.", type.FullName, memberName, parameterCount)) {
+            Type = type;
+            MemberName = memberName;
+            ParameterCount = parameterCount;
+        }
     }
 }

source/mtee/mtee.csproj

@@ -44,6 +44,7 @@
     <Compile Include="Engine\RuntimeType.cs" />
     <Compile Include="Engine\Processor.cs" />
     <Compile Include="Engine\Operator.cs" />
+    <Compile Include="exception\ConstructorException.cs" />
     <Compile Include="exception\MemberException.cs" />
     <Compile Include="exception\ParseException.cs" />
     <Compile Include="Model\Copyable.cs" />

source/sample/SlimSamples.cs

@@ -23,9 +23,6 @@ public class ShouldIBuyMilk {
         public string goToStore() {
             return (pints == 0 && (dollars > 2 || creditCard)) ? "yes" : "no";
         }
-
-        public void execute() {}
-        public void reset() {}
     }
 
     public class EmployeesHiredBefore {

source/unitTest/slim/ComposeOperatorsTest.cs

@@ -6,6 +6,7 @@
 using System;
 using System.Collections.Generic;
 using fitnesse.mtee.engine;
+using fitnesse.mtee.exception;
 using fitnesse.mtee.model;
 using fitnesse.slim.operators;
 using NUnit.Framework;
@@ -59,12 +60,28 @@ namespace fitnesse.unitTest.slim {
             Assert.AreEqual("c", result.Branches[1].Branches[1].Value); 
         }
 
+        [Test] public void ExceptionIsComposed() {
+            CheckExceptionCompose(new ApplicationException("blah"), string.Empty);
+        }
+
+        [Test] public void MemberExceptionIsComposed() {
+            CheckExceptionCompose(new MemberException(typeof(string), "garbage", 0), "message<<NO_METHOD_IN_CLASS garbage System.String>> ");
+        }
+
+        [Test] public void ConstructorExceptionIsComposed() {
+            CheckExceptionCompose(new ConstructorException(typeof(string), 0), "message<<NO_CONSTRUCTOR System.String>> ");
+        }
+
         private Tree<string> Compose(ComposeOperator<string> composeOperator, object instance, Type type) {
             Tree<string> result = null;
             Assert.IsTrue(composeOperator.TryCompose(processor, new TypedValue(instance, type), ref result));
             return result;
         }
 
+        private void CheckExceptionCompose(Exception exception, string expected) {
+            CheckCompose(new ComposeException(), exception, exception.GetType(), string.Format("__EXCEPTION__:{0}{1}", expected, exception));
+        }
+
         private void CheckCompose(ComposeOperator<string> composeOperator, object instance, Type type, object expected) {
             Tree<string> result = null;
             Assert.IsTrue(composeOperator.TryCompose(processor, new TypedValue(instance, type), ref result));

source/unitTest/slim/ExecuteOperatorsTest.cs

@@ -17,6 +17,7 @@ namespace fitnesse.unitTest.slim {
         [SetUp] public void SetUp() {
             processor = new Processor<string>();
             processor.AddOperator(new ComposeDefault());
+            processor.AddOperator(new ComposeException());
             processor.AddMemory<SavedInstance>();
             processor.AddMemory<Symbol>();
         }