Question

I have a unit test that I need to run for 200 possible combinations of data. (The production implementation has the data to be tested in configuration files. I know how to mock these values). I prefer nit writing separate test case for each combination and to use some way of looping through the data. Is there some such direct way using Google test for C++?

Answer 1

You can make use of gtest’s Value-parameterized tests for this.

Using this in conjunction with the Combine(g1, g2, ..., gN) generator sounds like your best bet.

The following example populates 2 vectors, one of ints and the other of strings, then with just a single test fixture, creates tests for every combination of available values in the 2 vectors:

#include <iostream>
#include <string>
#include <tuple>
#include <vector>
#include "gtest/gtest.h"

std::vector<int> ints;
std::vector<std::string> strings;

class CombinationsTest :
    public ::testing::TestWithParam<std::tuple<int, std::string>> {};

TEST_P(CombinationsTest, Basic) {
  std::cout << "int: "        << std::get<0>(GetParam())
            << "  string: \"" << std::get<1>(GetParam())
            << "\"\n";
}

INSTANTIATE_TEST_CASE_P(AllCombinations,
                        CombinationsTest,
                        ::testing::Combine(::testing::ValuesIn(ints),
                                           ::testing::ValuesIn(strings)));

int main(int argc, char **argv) {
  for (int i = 0; i < 10; ++i) {
    ints.push_back(i * 100);
    strings.push_back(std::string("String ") + static_cast<char>(i + 65));
  }
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}