I have been wanting to code properly with unit tests and continuous integration for a few years now and have never done it properly. 
# Development Process
## Unit Testing
### C++
In [[C++]] we use the [[GTest Framework|GoogleTest]] Framework.

## Code Coverage
Code coverage testing basically compiles the code with profiling flags, which count the number of times a specific line has been executed. And since google test runs the source code we can test if we are testing all the code that we have written.
For C++ typically, a tool called `gcovr` is used. In order for it to work you need to compile the code with the following flags: `-fprofile-arcs` and `-ftest-coverage`
If the project uses [[CMake]] you can add the following to your CMakeLists.txt:
```cmake
if(CMAKE_CXX_COMPILER_ID MATCHES GNU)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-arcs -ftest-coverage")

endif()
```



# Online Tools
In order to do continuous integration we need a place that automatically runs our unit tests whenever a commit is pushed.
## GitLab
Gitlab is known for its [[Gitlab - CI CD|CICD]] (Continuous Integration / Continuous Deployment) pipeline. It allows to customize and automate the entire process very effectively. The setup process is also very easy and explained well on [their website](https://docs.gitlab.com/ee/ci/quick_start/).

1. You must have runners[^1] available
2. Create a `.gitlab-ci.yml` file at the root of your repository. The entire pipeline of automated tests is defined in this file.

A good example repo can be found [here](https://github.com/pothitos/gtest-demo-gitlab/tree/master).
My own first gitlab-ci config file (`.gitlab-ci.yml`):
```yaml
image: ubuntu:20.04

job:
	script:
		- export DEBIAN_FRONTEND=noninteractive
		- apt-get update
		- apt-get install -y cmake g++ build-essential git gcovr 
		- cd onesec3d_cpp
		- mkdir build && cd build
		- cmake -DBUILD_TESTING=ON ..
		- cmake --build .
		- export DATADIR=../test/sample_3d_files/
		- ./test/onesec3d_cpp_test
		- gcovr --exclude-directories '_deps' -r ..
```
# Flashcards
#learning/cpp 
which command to do code coverage testing;;`gcovr`
<!--SR:!2023-12-21,14,290-->
requirements for `gcovr`;; project must be built with flags: `-fprofile-arcs` and `-ftest-coverage`
<!--SR:!2023-12-08,1,210-->

# Resources
- CI for robotics projects with [[ROS2]]: use [[Gazebo]] that is run on the gitlab server: http://moore-mike.com/bobble-ci.html
# Footnotes
[^1]: GitLab Runner is an application that can execute CI/CD jobs in a GitLab pipeline