Testing

Overview

Teaching: 30 min
Exercises: 5 min

Questions

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Objectives

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Lesson Contents

• Prerequisites
• The Catch2 package
  • Obtaining Catch2
• Writing simple tests

Prerequisites

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The Catch2 package

The Catch2 package https://github.com/catchorg/Catch2 is a testing framework for C++. It provides the ability to call and test functions in a similar manner to Pytest.

One main benefit of Catch2 is that it is “header only”, meaning that you only have to install or copy header files for use in your project, and do not have to build a Catch2 library and link against it.

Obtaining Catch2

The easiest way to get Catch2 is to download its single header file and place it with the rest of your files.

Download the single file using your favorite method (browser, wget, curl, etc):

https://raw.githubusercontent.com/catchorg/Catch2/v2.13.9/single_include/catch2/catch.hpp

Writing simple tests

To write tests with Catch2, we will be creating a new source file, test.cpp. This file will be compiled by itself, and not with your already-exiting main file.

This file will contain #define CATCH_CONFIG_MAIN at the top, which will automatically create a main function in this source file.

#define CATCH_CONFIG_MAIN
#include "catch.hpp"
#include "temperature.hpp"

double convert_temperature(double t)
{
    return t*1.8+32.0;
}

TEST_CASE("Temperature functions", "[temperature]")
{
    REQUIRE(convert_temperature(-40.0) == -40.0);
}

Now we will compile our new source file and the temperature.cpp file together.

g++ test.cpp temperature.cpp -o test_temperature

The test_temperature executable now has lots of command line arguments related to testing. Try running ./test_temperature -h and see!

To run your tests, just run ./test_temperature.

===============================================================================
All tests passed (1 assertion in 1 test case)

Key Points

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