Add coverage to CI via ctest_coverage

[tjanc]

Generate test coverage when running ctest with the script cmake/unix-coverage.cmake.

Notes

• gcov coverage files are in build/Testing/CoverageInfo/ after running

  $drafter> ctest -S cmake/unix-coverage.cmake

  For example:

      -:    0:Source:/home/tj/projects/apiary/drafter/src/refract/dsd/Number.cc
      -:    0:Graph:/home/tj/projects/apiary/drafter/build/src/CMakeFiles/drafter.dir/refract/dsd/Number.cc.gcno
      -:    0:Data:/home/tj/projects/apiary/drafter/build/src/CMakeFiles/drafter.dir/refract/dsd/Number.cc.gcda
      -:    0:Runs:1
      -:    0:Programs:1
      -:    1://
      -:    2://  refract/dsd/Number.cc
      -:    3://  librefract
      -:    4://
      -:    5://  Created by Thomas Jandecka on 04/09/2017
      -:    6://  Copyright (c) 2017 Apiary Inc. All rights reserved.
      -:    7://
      -:    8:
      -:    9:#include "Number.h"
      -:   10:
      -:   11:#include "Traits.h"
      -:   12:#include "../../utils/log/Trivial.h"
      -:   13:
      -:   14:using namespace refract;
      -:   15:using namespace dsd;
      -:   16:using namespace drafter::utils::log;
      -:   17:
      -:   18:const char* Number::name = "number";
      -:   19:
      -:   20:static_assert(!supports_erase<Number>::value, "");
      -:   21:static_assert(!supports_empty<Number>::value, "");
      -:   22:static_assert(!supports_insert<Number>::value, "");
      -:   23:static_assert(!supports_push_back<Number>::value, "");
      -:   24:static_assert(!supports_begin<Number>::value, "");
      -:   25:static_assert(!supports_end<Number>::value, "");
      -:   26:static_assert(!supports_size<Number>::value, "");
      -:   27:static_assert(!supports_erase<Number>::value, "");
      -:   28:static_assert(!supports_key<Number>::value, "");
      -:   29:static_assert(!supports_value<Number>::value, "");
      -:   30:static_assert(!supports_merge<Number>::value, "");
      -:   31:static_assert(!is_iterable<Number>::value, "");
      -:   32:static_assert(!is_pair<Number>::value, "");
      -:   33:
    366:   34:Number::Number(std::string v) noexcept : value_(v) {}
      -:   35:
   1856:   36:const std::string& Number::get() const noexcept
      -:   37:{
   1856:   38:    return value_;
      -:   39:}
      -:   40:
  #####:   41:Number::operator std::int64_t() const noexcept
      -:   42:{
      -:   43:    std::string::size_type idx;
  #####:   44:    std::int64_t result = std::stoi(value_, &idx);
  #####:   45:    if (idx < value_.size())
  #####:   46:        LOG(warning) << "dsd::Number to int; dropped trailing `" << value_.substr(idx) << "`";
  #####:   47:    return result;
      -:   48:}
      -:   49:
     79:   50:bool dsd::operator==(const Number& lhs, const Number& rhs) noexcept
      -:   51:{
     79:   52:    return lhs.get() == rhs.get();
      -:   53:}
      -:   54:
      3:   55:bool dsd::operator!=(const Number& lhs, const Number& rhs) noexcept
      -:   56:{
      3:   57:    return !(lhs == rhs);
      -:   58:}
  

• Currently, we don't have a way to show coverage reports in CI, because we've reached our maximum submissions on CDash. Either that will be solved in the coming days or we will find an alternative.