Unit Tests fail with exception code c0000005

Question

I am trying to create Unit Tests in Visual Studios 2012 using a Native Unit Test Project.

This is the test I have:

TEST_METHOD(CalculationsRoundTests)
{
    int result = Calculations::Round(1.0);
    Assert::AreEqual(1, result);
}

Exporting the Class:

#ifdef EXPORT_TEST_FUNCTIONS
#define MY_CALCULATIONS_EXPORT __declspec(dllexport)
#else
#define MY_CALCULATIONS_EXPORT
#endif
...
class CALCULATIONS_EXPORT Calculations {
...
public:
static int Round(const double& x);

The function itself:

int Calculations::Round(const double& x)
{
    int temp;
    if (floor(x) + 0.5 > x)
        temp = floor(x);
    else
        temp = ceil(x);

    return int(temp);
}

However, the test nearly always fails with error code c0000005 (Access Violation). The test will fail the first time that x, or any other variable that may be declared in the function, is used.

I followed the instructions at Unresolved externals when compiling unit tests for Visual C++ 2012

Answer 1

This is a known bug. Unfortunately, Microsoft considers this as "Won't Fix".

In short, there are two workarounds:

1. Compile the actual project in release mode and the test project in debug mode.
2. Outsource all testable functions to a static library project.