teststringwriter.cpp

#define BOOST_TEST_MAIN
#include <boost/test/included/unit_test.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <iostream>
#include <cstring>
#include "stringwriter.h"

using namespace std;

template<typename T, typename FromString, typename ToString, typename ToCharPtr>
T& strtransform(const std::string& ref, T& str, FromString fs, ToString ts, ToCharPtr ptr)
{
  fs(str,ref);
  BOOST_CHECK(ts(str) == ref);
  auto c1 = ptr(str);
  c1 += 4;
  auto c1x = c1 + 3;
  *c1 = 'x';
  *c1x = 'y';
  for(unsigned i=0; c1[i]; ++i)
    if (c1[i] == 'i') {
      c1[i] = 'a';
      //cout << i << endl;
    }
  while (auto c = strstr(c1, "\n")) {
    *c = '_';
  }
  //c1x[1000] = 'z'; <-- may crash with char*, will checked with StringWriter
  BOOST_CHECK(ts(str) != ref);
  return str;
}

BOOST_AUTO_TEST_SUITE( TestStringWriter )

BOOST_AUTO_TEST_CASE(testStringWriterStrcpy)
{
  const std::string s{"This is some silly text without any meaning."};
  std::string s1{s};
  StringWriter sw1{s1};
  sw1 += 17;
  char *s2 = strdup(s.c_str());
  char *sw2 = s2;
  sw2 += 17;
  BOOST_CHECK(strlen(s1) == strlen(s2));
  BOOST_CHECK(!strcmp(s1.c_str(), s2));
  BOOST_CHECK(!strcmp(sw1.c_str(), sw2));
  strcpy(sw1, "hallo");
  strcpy(sw2, "hallo");
  BOOST_CHECK(strlen(sw1) == strlen(sw2));
  BOOST_CHECK(!strcmp(s1.c_str(), s2));
  sw1[5] = ' '; // replace the \0 byte
  sw2[5] = ' ';
  BOOST_CHECK(s1 == s2);
}

BOOST_AUTO_TEST_CASE(testStringWriter)
{
  std::string s{"This a text\nwith several line\nbreaks and some longer lines\n and shorter ones."};

  std::string s2;
  std::string s2x = strtransform(s, s2,
      [](std::string& str, const std::string& s){ str = s; },
      [](const std::string& s){ return s; },
      [](std::string& s){ return StringWriter(s,0); }
      );
  //cout << s2 << endl;

  char *s3 = new char[s.size()+1];
  strtransform(s, s3,
      [](char *str, const std::string& s){ strcpy(str,s.c_str()); },
      [](char *s){ return std::string(s); },
      [](char *s){ return s; }
      );
  //cout << s3 << endl;

  BOOST_CHECK(std::string(s3) == s2);
  BOOST_CHECK(s2 == s2x);
}

// examples from the README.md
void g1(char *s)
{
  char *sc = s+3;
  *sc = 'a';
  while (char *scc = strstr(sc, "b"))
    *scc = 'c';
}

void g2(char *s)
{
  auto sc = s+3;
  *sc = 'a';
  while (auto scc = strstr(sc, "b"))
    *scc = 'c';
}

void g3(std::string& str)
{
  StringWriter s{str};
  auto sc = s+3;
  *sc = 'a';
  while (auto scc = strstr(sc, "b"))
    *scc = 'c';
}
BOOST_AUTO_TEST_CASE(testExamples)
{
  std::string s{"This is another simple text"};
  char sg1[s.size()+1];
  strcpy(sg1, s.c_str());
  g1(sg1);
  char sg2[s.size()+1];
  strcpy(sg2, s.c_str());
  g2(sg2);
  std::string sg3{s};
  g3(sg3);
  BOOST_CHECK(sg3 != s);
  BOOST_CHECK(sg3 == sg2);
  BOOST_CHECK(sg3 == sg1);
  BOOST_CHECK(!strcmp(sg1, sg2));
}

BOOST_AUTO_TEST_SUITE_END()