coverage_shield

A package to create and maintain a package unit test coverage badge in python code README. Importantly there are quite a few python packages that do this task or similar:

• genbadge - generates badges (as images) for a range of python tools including a coverage one
• coverage-badge - generates badge as image
• readme-coverage-badger - adds coverage badge to README if you have already run tests

I created the coverage_shield package mainly as a learning exercise for myself but also to have a tool that runs my tests and updates a coverage badge in one go.

It works by first running the coverage python package to generate a coverage report and puts the result into a structure url using the shields.io service. For example, the average_coverage and badge_colour variables can be fed into this url structure:

https://img.shields.io/badge/coverage-{average_coverage}%25-{badge_colour}

Tasks

• TODO create a release
• TODO look into getting published on pip
• TODO improve coverage of tests for git functions if possible

Installing coverage_shield 📦

To install this package, follow these two steps:

1. Clone the repository with (or something similar): git clone https://github.com/JosephCrispell/coverage_shield.git
2. Navigate to the repository and install with: pip install .

Updating coverage badge 🔃

To update the coverage badge of your repo, run the following from within the root folder of your repository:

python -m coverage_shield

There are a few command line arguments you can use, take a look with python -m coverage_shield --help:

usage: coverage_shield [-h] [-d [directory]] [-r [readme_path]] [-t [tester]] [-g]

Welcome to coverage_shield! A tool to create and maintain a python package unit test coverage badge in README.md

options:
  -h, --help            show this help message and exit
  -d [directory], --directory [directory]
                        Provide path to directory to run coverage_shield in. (default: .)
  -r [readme_path], --readme [readme_path]
                        Provide path to README.md relative to directory provided. (default: README.md)
  -t [tester], --tester [tester]
                        Provide name of unit test python package you want to use. Accepts either "unittest" or "pytest" (default: unittest)
  -g, --git_push        Stage, commit, and push the updated README file (-r/--readme) using git. (default: False)

Ignoring patterns

If you'd like to ignore the unit test coverage for particular files in your coverage report you can created a .covignore file in your repository directory. For example, here's the content of the .covignore file for this project:

setup.py
__init__.py

The .covignore works in a similar way to a .gitignore file and any pattern found in it is passed to the str.contains() function and used to filter the unit test coverage report before calculate the average coverage for the project. So the above means that any setup.py or __init__.py files are ignored.

For Developers

Installation for development

As above to install clone the repo but run pip install -e .. The -e flag means the package will automatically update as you change the codebase.

Package structure

Directory tree generated using file-tree-generator Visual Studio Code extension:

📦coverage_shield
 ┣ 📂coverage_shield
 ┃ ┣ 📜__main__.py # script that is called when you call package (python -m coverage_shield)
 ┃ ┣ 📜command_line_interface_functions.py # functions for the command line interface
 ┃ ┣ 📜git_functions.py # functions to staging, committing, and pushing updated README to remote
 ┃ ┣ 📜unittest_coverage_functions.py # functions to calculate coverage and update badge
 ┃ ┗ 📜__init__.py # package structure/info
 ┣ 📂images
 ┃ ┗ 📜logo.svg
 ┣ 📂tests
 ┃ ┣ 📜test_command_line_interface_functions.py # unit tests for cli
 ┃ ┣ 📜test_git_functions.py # unit tests for git functions
 ┃ ┣ 📜test_main.py # unit tests for main script
 ┃ ┣ 📜test_unittest_coverage_functions.py # unit tests for functions to create/update coverage badge
 ┃ ┗ 📜__init__.py # package structure/info
 ┣ 📜.covignore # patterns/files to ignore when calculating coverage
 ┣ 📜.gitignore
 ┣ 📜.pre-commit-config.yaml # precommit workflow
 ┣ 📜LICENSE
 ┣ 📜README.md
 ┣ 📜requirements.txt
 ┗ 📜setup.py

precommit installation ✔

Install python pre-commit with:

pip install pre-commit

Within repository folder run to install hooks:

pre-commit install

Running tests 🧪

Unit tests (using the unittest package) are in tests/ can be ran all together with:

python -m unittest

Workflow ➡

I created the following simple diagram using mermaid to show how the code and outputs link together.

  graph TD
    coverage_functions[coverage_shield/unittest_coverage_functions.py] .-> main[coverage_shield/__main__.py];
    coverage_functions .-> test_coverage[tests/test_unittest_coverage_functions.py];
    main --> readme[README.md];
    main .-> test_main[tests/test_main.py];
    cli_functions[coverage_shield/command_line_interface_functions.py] .-> main;
    cli_functions .-> test_cli[tests/test_command_line_interface_functions.py];
    git_functions[coverage_shield/git_functions.py] .-> main;
    git_functions .-> test_git[tests/test_git_functions.py];
    subgraph "unittests"
        test_coverage;
        test_cli;
        test_git;
        test_main;
    end
    unittests .-> coverage_functions

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