CATCH Unit Testing Suite with Visual Studio 2010

Question

As far as I understand it, I can simply place catch.hpp into my project directory, add it to the project, and then start writing tests. I'm running into a few, or 11 to be exact, linker errors once I try using some of the macros outlined in the tutorial.

#include "catch.hpp"

unsigned int Factorial( unsigned int number ) {
    return number <= 1 ? number : Factorial(number-1)*number;
}

TEST_CASE( "Factorials are computed", "[factorial]" ) {
    REQUIRE( Factorial(1) == 1 );
    REQUIRE( Factorial(2) == 2 );
    REQUIRE( Factorial(3) == 6 );
    REQUIRE( Factorial(10) == 3628800 );
}

I'm able to create a single file out of the first example and compile it with g++, but when I just paste the same code into my VS2010 project and then try to run it, I run into the linker errors. Unfortunately I'm not familiar enough with C++ at this point to decode the errors myself, and after taking a look at the single file here, I was unable to discern the issue.

Error   1   error LNK2019: unresolved external symbol "public: __thiscall Catch::AutoReg::AutoReg(void (__cdecl*)(void),struct Catch::SourceLineInfo const &,struct Catch::NameAndDesc const &)" (??0AutoReg@Catch@@QAE@P6AXXZABUSourceLineInfo@1@ABUNameAndDesc@1@@Z) referenced in function "void __cdecl `anonymous namespace'::`dynamic initializer for 'autoRegistrar27''(void)" (??__EautoRegistrar27@?A0x3911e331@@YAXXZ)    C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   2   error LNK2019: unresolved external symbol "public: __thiscall Catch::ExpressionResultBuilder::ExpressionResultBuilder(enum Catch::ResultWas::OfType)" (??0ExpressionResultBuilder@Catch@@QAE@W4OfType@ResultWas@1@@Z) referenced in function __catch$?____C_A_T_C_H____T_E_S_T____27@@YAXXZ$0   C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   3   error LNK2019: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl Catch::translateActiveException(void)" (?translateActiveException@Catch@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ) referenced in function __catch$?____C_A_T_C_H____T_E_S_T____27@@YAXXZ$0   C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   4   error LNK2019: unresolved external symbol "public: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionResultBuilder::endExpression(enum Catch::ResultDisposition::Flags)" (?endExpression@ExpressionResultBuilder@Catch@@QAEAAV12@W4Flags@ResultDisposition@2@@Z) referenced in function "void __cdecl ____C_A_T_C_H____T_E_S_T____27(void)" (?____C_A_T_C_H____T_E_S_T____27@@YAXXZ)   C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   5   error LNK2019: unresolved external symbol "public: __thiscall Catch::AssertionInfo::AssertionInfo(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,struct Catch::SourceLineInfo const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,enum Catch::ResultDisposition::Flags)" (??0AssertionInfo@Catch@@QAE@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABUSourceLineInfo@1@0W4Flags@ResultDisposition@1@@Z) referenced in function "void __cdecl ____C_A_T_C_H____T_E_S_T____27(void)" (?____C_A_T_C_H____T_E_S_T____27@@YAXXZ) C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   6   error LNK2019: unresolved external symbol "struct Catch::IContext & __cdecl Catch::getCurrentContext(void)" (?getCurrentContext@Catch@@YAAAUIContext@1@XZ) referenced in function "struct Catch::IResultCapture & __cdecl Catch::getResultCapture(void)" (?getResultCapture@Catch@@YAAAUIResultCapture@1@XZ)    C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   7   error LNK2019: unresolved external symbol "public: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionResultBuilder::setOp(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?setOp@ExpressionResultBuilder@Catch@@QAEAAV12@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "private: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionLhs<int const &>::captureExpression<0,int>(int const &)" (??$captureExpression@$0A@H@?$ExpressionLhs@ABH@Catch@@AAEAAVExpressionResultBuilder@1@ABH@Z) C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   8   error LNK2019: unresolved external symbol "public: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionResultBuilder::setRhs(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?setRhs@ExpressionResultBuilder@Catch@@QAEAAV12@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "private: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionLhs<int const &>::captureExpression<0,int>(int const &)" (??$captureExpression@$0A@H@?$ExpressionLhs@ABH@Catch@@AAEAAVExpressionResultBuilder@1@ABH@Z)   C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   9   error LNK2019: unresolved external symbol "public: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionResultBuilder::setLhs(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?setLhs@ExpressionResultBuilder@Catch@@QAEAAV12@ABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "private: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionLhs<int const &>::captureExpression<0,int>(int const &)" (??$captureExpression@$0A@H@?$ExpressionLhs@ABH@Catch@@AAEAAVExpressionResultBuilder@1@ABH@Z)   C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   10  error LNK2019: unresolved external symbol "public: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionResultBuilder::setResultType(bool)" (?setResultType@ExpressionResultBuilder@Catch@@QAEAAV12@_N@Z) referenced in function "private: class Catch::ExpressionResultBuilder & __thiscall Catch::ExpressionLhs<int const &>::captureExpression<0,int>(int const &)" (??$captureExpression@$0A@H@?$ExpressionLhs@ABH@Catch@@AAEAAVExpressionResultBuilder@1@ABH@Z)  C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   11  error LNK2019: unresolved external symbol "public: __thiscall Catch::AutoReg::~AutoReg(void)" (??1AutoReg@Catch@@QAE@XZ) referenced in function "void __cdecl `anonymous namespace'::`dynamic atexit destructor for 'autoRegistrar27''(void)" (??__FautoRegistrar27@?A0x3911e331@@YAXXZ)    C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\FirstCPPApplication\FirstCPPApplication.obj 1   1   FirstCPPApplication
Error   12  error LNK1120: 11 unresolved externals  C:\Users\Mark\documents\visual studio 2010\Projects\FirstCPPApplication\Debug\FirstCPPApplication.exe   FirstCPPApplication

Answer 1

long story short: split your single project solution into 3, use a .lib of the old exe, add the projects to the appropriate paths, update the linker, and you're good to go.

AE Drew's answer helped solve my problem, but I want to put a more full solution to the question's title, in case anyone's coming from Google, especially if they are looking for a simple breakdown from a beginner's perspective.

If you only had one project in your solution that built a .exe for you, CATCH wouldn't work: your solution needs 3 projects (as far as I know) to be able to test your code.

• Source_project, The main codebase project (in which the source code for your application resides)

• Test_project, The test suites project (in which the REQUIRES tests appear as outlined in the above question)

• Main_project, The project where you actually call and run the code from the source codebase.

In order to convert your original single-project solution into something that you can use in both tests and to properly run, you'll need to build a .lib or a .dll so that other projects (including other people's projects) can use the same code. Altering this answer, all it takes is to

right-click on your project in the Solution Explorer, and select > Properties.... Under Configuration Properties -> General there's an > option called Configuration Type. If you change it to [Static Library > (.lib)], your project will generate a [.lib] when it is built.

And then in the 3rd project, main_project, where you have a barebones setup from a Win32 Console Application that only contains a file that looks something like:

#include "stdafx.h"
#include "HEADER_FROM_FIRST_PROJECT.h"

int _tmain(int argc, _TCHAR* argv[])
{
   METHOD_FROM_FIRST_PROJECT();
   return 0;
}

where you import a header file from Source_project, the first project that we created (the one that used to be an exe, but is now building to a lib). But that's not going to run yet, you need to add the Source_project's directory to this projects additional directories, by right clicking the project in the Solution Explorer, under Properties > Configuration Properties > C/C++ > General > Additional Include Directories, add the source_project's folder to the list. This'll allow the #include lines to automatically search that directory for the appropriate files, saving you from having to write ../source_project/HEADER_FROM_FIRST_PROJECT.h.

Finally, the last step is to make sure that the linker will be able to actually find the objects that you are trying to include. And since we're building a .lib, we're able to do this rather simply. In the same settings dialog box as before, the Projects Properties dialog, we'll navigate instead to Configuration Properties > Linker > Input > Additional Dependencies and add the relative path to the source_project.lib file, which would look something like ../Debug/source_project.lib.

Note that if you have any .dlls that are in the old exe project, it'll need to be moved into the new main_project.

Also note that this is all very new to me and some of the terms and information are bound to be incorrect.

Answer 2

Just scanning through the links you provide, I think you may need to add this line at the top of your file.

#define CATCH_CONFIG_MAIN  // This tells Catch to provide a main() - only do this in one cpp file

It looks like the functions you are trying to link are within #if defined CATCH_CONFIG_MAIN .... #endif preprocessor directives.