#include <stan/math/rev.hpp>
#include <gtest/gtest.h>
#include <string>

class ErrorHandlingScalar_invalid_argument : public ::testing::Test {
 public:
  const char* function_ = "function";
  const char* y_name_ = "y";
  const char* msg1_ = "error_message ";
  const char* msg2_ = " after y";
  void SetUp() {}

  template <class T>
  std::string expected_message_with_message(T y) {
    std::stringstream expected_message;
    expected_message << "function: " << y_name_ << " error_message " << y
                     << " after y";
    return expected_message.str();
  }

  template <class T>
  std::string expected_message_without_message(T y) {
    std::stringstream expected_message;
    expected_message << "function: " << y_name_ << " error_message " << y;
    return expected_message.str();
  }

  template <class T>
  void test_throw(T y) {
    try {
      stan::math::invalid_argument<T>(function_, y_name_, y, msg1_, msg2_);
      FAIL() << "expecting call to invalid_argument<> to throw a "
             << "invalid_argument, "
             << "but threw nothing";
    } catch (std::invalid_argument& e) {
      EXPECT_EQ(expected_message_with_message(y), e.what());
    } catch (...) {
      FAIL() << "expecting call to invalid_argument<> to throw a "
             << "invalid_argument, "
             << "but threw a different type";
    }

    try {
      stan::math::invalid_argument<T>(function_, y_name_, y, msg1_);
      FAIL() << "expecting call to invalid_argument<> to throw a "
             << "invalid_argument, "
             << "but threw nothing";
    } catch (std::invalid_argument& e) {
      EXPECT_EQ(expected_message_without_message(y), e.what());
    } catch (...) {
      FAIL() << "expecting call to invalid_argument<> to throw a "
             << "invalid_argument, "
             << "but threw a different type";
    }
  }
};

TEST_F(ErrorHandlingScalar_invalid_argument, var) {
  stan::math::var y = 10;

  test_throw<stan::math::var>(y);
}
