How to limit pytest code coverage calculation to only specific files? - pytest

Question

I am trying to setup continues integration in github using actions. I setup a action to get the code coverage automatically, this part works great, however it's calculating the code coverage for every file in my src directory, this is not preferred, I would like it to calculate the code coverage for only the files modified, how do I do that?
name: Pytest Coverage
on:
pull_request:
branches: [ main, dev ]
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout#v2
- name: Set up Python 3.10
uses: actions/setup-python#v2
with:
python-version: "3.10"
- name: Install dependencies
run: |
python -m pip install --upgrade pip
pip install flake8 pytest pytest-cov
if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
- name: Changed Files Exporter
id: files
uses: umani/changed-files#v3.3.0
with:
repo-token: ${{ github.token }}
pattern: '^src.*\.(py)$'
result-encoding: 'string'
- name: Build coverage file
run: |
echo "${{ steps.files.outputs.files_updated }} ${{ steps.files.outputs.files_created }}"
pytest --cache-clear --cov-branch --cov=src > pytest-coverage.txt
- name: Comment coverage
uses: coroo/pytest-coverage-commentator#v1.0.2
- name: Get Coverage %
run: |
LAST_LINE=$(tail -4 pytest-coverage.txt)
LAST_LINE=$(head -n 1 <<< "$LAST_LINE")
COVERAGE=$(sed 's/.*[[:space:]]\([0-9]\+\)%/\1/' <<< "$LAST_LINE")
echo "Overall code coverage is $COVERAGE"
echo 'SCORE<<EOF' >> $GITHUB_ENV
echo "$SCORE" >> $GITHUB_ENV
echo 'EOF' >> $GITHUB_ENV
The important 2 lines are here:
echo "${{ steps.files.outputs.files_updated }} ${{ steps.files.outputs.files_created }}"
pytest --cache-clear --cov-branch --cov=src > pytest-coverage.txt
The echo print out the correct files:
src/scripts/testing_script.py src/server.py
How do I change this line so it ONLY calculate the total coverage of thoese 2 modified files?
pytest --cache-clear --cov-branch --cov=src > pytest-coverage.txt