diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..9cd8f49
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,47 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - "main"
+
+concurrency:
+  group: CI
+
+jobs:
+  test:
+    name: Run tests & display/prepare coverage
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - run: pip install -e .
+        working-directory: subdir
+
+      - run: pytest
+        working-directory: subdir
+
+      - name: Coverage comment
+        id: coverage_comment
+        uses: py-cov-action/python-coverage-comment-action@032f1914e3f12a555f8ca8322f949c24a829072e
+        with:
+          GITHUB_TOKEN: ${{ github.token }}
+          ANNOTATE_MISSING_LINES: true
+          ANNOTATION_TYPE: notice
+          COVERAGE_PATH: subdir
+          SUBPROJECT_ID: "my-great-project"
+
+      - name: Store Pull Request comment to be posted
+        uses: actions/upload-artifact@v4
+        if: steps.coverage_comment.outputs.COMMENT_FILE_WRITTEN == 'true'
+        with:
+          name: python-coverage-comment-action
+          path: python-coverage-comment-action*.txt
diff --git a/.github/workflows/coverage-comment.yml b/.github/workflows/coverage-comment.yml
new file mode 100644
index 0000000..9d2e6a6
--- /dev/null
+++ b/.github/workflows/coverage-comment.yml
@@ -0,0 +1,25 @@
+name: Post coverage comment
+
+on:
+  workflow_run:
+    workflows: ["CI"]
+    types:
+      - completed
+
+jobs:
+  test:
+    name: Publish coverage Comment
+    runs-on: ubuntu-latest
+    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
+    permissions:
+      actions: read
+      pull-requests: write
+      contents: write
+    steps:
+      - name: Post comment
+        uses: py-cov-action/python-coverage-comment-action@032f1914e3f12a555f8ca8322f949c24a829072e
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_PR_RUN_ID: ${{ github.event.workflow_run.id }}
+          COVERAGE_PATH: subdir
+          SUBPROJECT_ID: "my-great-project"
diff --git a/subdir/end_to_end_tests_repo/__init__.py b/subdir/end_to_end_tests_repo/__init__.py
new file mode 100644
index 0000000..ea5c570
--- /dev/null
+++ b/subdir/end_to_end_tests_repo/__init__.py
@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+
+def f(a="", b="", c="", d=""):
+    elements = []
+    if a:
+        elements.append(a)
+
+    if b:
+        elements.append(b)
+
+    if c:
+        elements.append(c)
+
+    if d:
+        elements.append(d)
+
+    return "-".join(elements)
diff --git a/subdir/pyproject.toml b/subdir/pyproject.toml
new file mode 100644
index 0000000..035a8ff
--- /dev/null
+++ b/subdir/pyproject.toml
@@ -0,0 +1,13 @@
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "end-to-end-tests"
+version = "0.0.0"
+dependencies = [
+    "pytest",
+    "pytest-cov",
+]
+
+[tool.setuptools.packages.find]
diff --git a/subdir/setup.cfg b/subdir/setup.cfg
new file mode 100644
index 0000000..319c688
--- /dev/null
+++ b/subdir/setup.cfg
@@ -0,0 +1,9 @@
+[coverage:run]
+relative_files = true
+
+[tool:pytest]
+addopts =
+    --cov-report term-missing --cov-branch --cov-report html
+    --cov=end_to_end_tests_repo -vv --strict-markers -rfE
+testpaths =
+    tests
diff --git a/subdir/tests/cases.csv b/subdir/tests/cases.csv
new file mode 100644
index 0000000..9ee88e0
--- /dev/null
+++ b/subdir/tests/cases.csv
@@ -0,0 +1,2 @@
+a,,,,a
+a,b,,,a-b
diff --git a/subdir/tests/test_f.py b/subdir/tests/test_f.py
new file mode 100644
index 0000000..f48c645
--- /dev/null
+++ b/subdir/tests/test_f.py
@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+import csv
+import pathlib
+
+import end_to_end_tests_repo
+import pytest
+
+
+def load_csv():
+    file = pathlib.Path(__file__).parent / "cases.csv"
+    return list(csv.reader(file.read_text().splitlines()))
+
+
+@pytest.mark.parametrize("a, b, c, d, expected", load_csv())
+def test_f(a, b, c, d, expected):
+    assert end_to_end_tests_repo.f(a=a, b=b, c=c, d=d) == expected