assert.h

//          Copyright Joakim Karlsson & Kim Gräsman 2010-2013.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#ifndef IGLOO_ASSERT_H
#define IGLOO_ASSERT_H

#include "stringize.h"
#include "stringizers.h"

namespace snowhouse {

   class Assert
   {
   public:

      template <typename ActualType, typename ConstraintListType>
      static void That(const ActualType& actual, ExpressionBuilder<ConstraintListType> expression)
      {
        const char* no_file = "";
        int line_number = 0;

        Assert::That(actual, expression, no_file, line_number);
      }
      
      template <typename ActualType, typename ConstraintListType>
      static void That(const ActualType& actual, ExpressionBuilder<ConstraintListType> expression, const char* file_name, int line_number)
      {
         try 
         {
            ResultStack result;
            OperatorStack operators;
            expression.Evaluate(result, operators, actual);

            while (!operators.empty())
            {
               ConstraintOperator* op = operators.top();
               op->PerformOperation(result);
               operators.pop();
            }

            if (result.empty())
            {
               throw InvalidExpressionException("The expression did not yield any result");
            }

            if (!result.top())
            {
               throw AssertionException(CreateErrorText(expression, actual), file_name, line_number);
            }      
         }
         catch (const InvalidExpressionException& e) 
         {
            throw AssertionException("Malformed expression: \"" + snowhouse::Stringize(expression) + "\"\n" + e.Message());
         }
      }

      template <typename ConstraintListType>
      static void That(const char* actual, ExpressionBuilder<ConstraintListType> expression)
      {
         return That(std::string(actual), expression);
      }

      template <typename ActualType, typename ExpressionType>
      static void That(const ActualType& actual, const ExpressionType& expression)
      {
        const char* no_file = "";
        int no_line = 0;
        That(actual, expression, no_file, no_line);
      }

      template <typename ActualType, typename ExpressionType>
      static void That(const ActualType& actual, const ExpressionType& expression, const char* file_name, int line_number)
      {
         if (!expression(actual))
         {
            throw AssertionException(CreateErrorText(expression, actual), file_name, line_number);
         }
      }

      template <typename ExpressionType>
      static void That(const char* actual, const ExpressionType& expression)
      {
         return That(std::string(actual), expression);
      }

      static void That(bool actual)
      {
         if (!actual)
         {
            throw AssertionException("Expected: true\nActual: false");
         }
      }

      static void Failure(const std::string& message)
      {
         throw AssertionException(message);
      }

   private:
      template <class ExpectedType, class ActualType>
      static std::string CreateErrorText(const ExpectedType& expected, const ActualType& actual)
      {
         std::ostringstream str;

         str << "Expected: " << snowhouse::Stringize(expected) << std::endl;
         str << "Actual: " << snowhouse::Stringize(actual) << std::endl;

         return str.str();
      }
   };
}

#endif  // IGLOO_ASSERT_H