p-ranav-argparse/test/test_help.cpp

#include <argparse/argparse.hpp>
#include <doctest.hpp>
#include <sstream>

using doctest::test_suite;

TEST_CASE("Users can format help message" * test_suite("help")) {
  argparse::ArgumentParser program("test");

  SUBCASE("Simple arguments") {
    program.add_argument("input").help("positional input");
    program.add_argument("-c").help("optional input");
  }
  SUBCASE("Default values") {
    program.add_argument("-a").default_value(42);
    program.add_argument("-b").default_value(4.4e-7);
    program.add_argument("-c")
        .default_value(std::vector<int>{1, 2, 3, 4, 5})
        .nargs(5);
    program.add_argument("-d").default_value("I am a string");
    program.add_argument("-e").default_value(std::optional<float>{});
    program.add_argument("-f").default_value(false);
  }
  std::ostringstream s;
  s << program;
  REQUIRE_FALSE(s.str().empty());

  auto msg = program.help().str();
  REQUIRE(msg == s.str());
}

TEST_CASE("Users can override the help options" * test_suite("help")) {
  GIVEN("a program that meant to take -h as a normal option") {
    argparse::ArgumentParser program("test");
    program.add_argument("input");
    program.add_argument("-h").implicit_value('h').default_value('x');

    WHEN("provided -h without fulfilling other requirements") {
      THEN("validation fails") {
        REQUIRE_THROWS_AS(program.parse_args({"test", "-h"}),
                          std::runtime_error);
      }
    }

    WHEN("provided arguments to all parameters") {
      program.parse_args({"test", "-h", "some input"});

      THEN("these parameters get their values") {
        REQUIRE(program["-h"] == 'h');
        REQUIRE(program.get("input") == "some input");
      }
    }
  }
}

TEST_CASE("Users can disable default -h/--help" * test_suite("help")) {
  argparse::ArgumentParser program("test", "1.0",
                                   argparse::default_arguments::version);
  REQUIRE_THROWS_AS(program.parse_args({"test", "-h"}), std::runtime_error);
}

TEST_CASE("Users can replace default -h/--help" * test_suite("help")) {
  argparse::ArgumentParser program("test", "1.0",
                                   argparse::default_arguments::version);
  std::stringstream buffer;
  program.add_argument("-h", "--help")
    .action([&](const auto &) {
      buffer << program;
    })
    .default_value(false)
    .implicit_value(true)
    .nargs(0);

  REQUIRE(buffer.str().empty());
  program.parse_args({"test", "--help"});
  REQUIRE_FALSE(buffer.str().empty());
}