lest_sections.cpp

// lest light-weight sections

// [1] Catch: Test cases and sections,
//     https://github.com/philsquared/Catch/blob/develop/docs/tutorial.md#test-cases-and-sections
// [2] lest – lest errors escape testing,
//     https://github.com/martinmoene/lest#lest--lest-errors-escape-testing---10

#include <cassert>
#include <iostream>
#include <string>
#include <vector>

#define EXPECT(...) assert(__VA_ARGS__)

#define MK_NAM3( name, line ) name##line
#define MK_NAM2( name, line ) MK_NAM3( name, line )
#define MK_NAME( name       ) MK_NAM2( name, __LINE__ )

#define SETUP(...) \
    for ( int $section = 0, $count = 1; $section < $count; ++$section )

#define SECTION( name ) \
    static int MK_NAME( $id ) = 0; \
    if ( $guard $run = $guard( MK_NAME( $id ), $section, $count, name ) ) \
        for ( int $section = 0, $count = 1; $section < $count; ++$section )

struct $guard
{
    int & id;
    int const & section;
    std::string const & name;

    $guard( int & id, int const & section, int & count, std::string const & name )
    : id( id ), section( section ), name( name )
    {
        if ( section == 0 )
        {
            id = count++;
        }
    }
    operator bool() { return id == section; }
};

// single level of setup, teardown:

void CASE_A()
{
    // SETUP
    // first pass counts number of sections:

    for ( int $section = 0, $count = 1; $section < $count; ++$section )
    {
        int i = 42;
        std::cout << "case A start, i:" << i << "\n";

        // SECTION
        static int id1 = 0;
        std::cout << "section A1 id1:" << id1 << "\n";
        if ( $guard $run = $guard( id1, $section, $count, "Section A1" ) )
        {
            EXPECT( i == 42 );
            std::cout << "section A1 start, i:" << i << "\n";
            i = 66;
            std::cout << "section A1 body, i:" << i << "\n";
        }

        // SECTION
        static int id2 = 0;
        std::cout << "section A2 id2:" << id2 << "\n";
        if ( $guard $run = $guard( id2, $section, $count, "Section A2" ) )
        {
            EXPECT( i == 42 );
            std::cout << "section A2 start, i:" << i << "\n";
            i = 77;
            std::cout << "section A2 body, i:" << i << "\n";
        }
    }
}

// setup, teardown at section level:

void CASE_B()
{
    // SETUP
    // first pass counts number of sections:

    for ( int $section = 0, $count = 1; $section < $count; ++$section )
    {
        // SECTION
        static int id1 = 0;
        if ( $guard $run = $guard( id1, $section, $count, "Section A1" ) )
            for ( int $section = 0, $count = 1; $section < $count; ++$section )
            {
                int i = 42;

                // SECTION
                static int id1 = 0;
                if ( $guard $run = $guard( id1, $section, $count, "Section A2" ) )
                    for ( int $section = 0, $count = 1; $section < $count; ++$section )
                    {
                        i = 777;
                    }

                // SECTION
                static int id2 = 0;
                if ( $guard $run = $guard( id2, $section, $count, "Section A2" ) )
                    for ( int $section = 0, $count = 1; $section < $count; ++$section )
                    {
                        EXPECT( i == 42 );
                    }
            }

    }
}

void CASE_C()
{
    SETUP("Sections share setup and (scoped) teardown code")
    {
        int i = 42;

        SECTION( "Section 1" )
        {
            i = 1;
            int j = 42;

            SECTION( "Section 11" )
            {
                i = j = 11;
                int k = 42;

                SECTION( "Section 111" )
                {
                    i = j = k = 111;
                }
                SECTION( "Section 112" )
                {
                    EXPECT( i == 11 );
                    EXPECT( j == 11 );
                    EXPECT( k == 42  );
                }
            }
            SECTION( "Section 12" )
            {
                EXPECT( i == 1  );
                EXPECT( j == 42 );
            }
        }
        SECTION( "Section 2" )
        {
            EXPECT( i == 42 );
        }
    }
}

#define SCENARIO(...)   void CASE_S()
#define GIVEN(name  )   SETUP(   std::string("Given: " ) + name )
#define WHEN( name  )   SECTION( std::string("When: "  ) + name )
#define THEN( name  )   SECTION( std::string("Then: "  ) + name )

SCENARIO( "vectors can be sized and resized", "[vector]" ) {

    GIVEN( "A vector with some items" ) {
        std::vector<int> v( 5 );

        EXPECT( v.size() == 5 );
        EXPECT( v.capacity() >= 5 );

        WHEN( "the size is increased" ) {
            v.resize( 10 );

            THEN( "the size and capacity change" ) {
                EXPECT( v.size() == 10 );
                EXPECT( v.capacity() >= 10 );
            }
            continue;
        }
        WHEN( "the size is reduced" ) {
            v.resize( 0 );

            THEN( "the size changes but not capacity" ) {
                EXPECT( v.size() == 0 );
                EXPECT( v.capacity() >= 5 );
            }
            continue;
        }
        WHEN( "more capacity is reserved" ) {
            v.reserve( 10 );

            THEN( "the capacity changes but not the size" ) {
                EXPECT( v.size() == 5 );
                EXPECT( v.capacity() >= 10 );
            }
            continue;
        }
        WHEN( "less capacity is reserved" ) {
            v.reserve( 0 );

            THEN( "neither size nor capacity are changed" ) {
                EXPECT( v.size() == 5 );
                EXPECT( v.capacity() >= 5 );
            }
            continue;
        }
    }
}

int main()
{
    CASE_A();
    CASE_B();
    CASE_C();
    CASE_S();
}
// cl -nologo -W3 -EHsc -I.. lest_sections.cpp && lest_sections
// g++ -Wall -Wextra -Wmissing-include-dirs -std=c++11 -I.. -o lest_sections.exe lest_sections.cpp && lest_sections