feat: Added comprehensive unit testing and github action to run tests on new pull requests

.github/workflows/tests.yml

@@ -19,3 +19,14 @@
           pip install -e ".[dev]"
       - name: Run all tests
         run: pytest
+
+  integration-test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Run integration test with docker compose
+      run: |
+        docker compose up --build --abort-on-container-exit --exit-code-from github-etl
+    - name: Cleanup
+      if: always()
+      run: docker compose down -v

Dockerfile

@@ -1,5 +1,5 @@
 # Use the latest stable Python image
-FROM python:3.11-slim
+FROM python:3.14.2-slim
 
 # Set environment variables
 ENV PYTHONDONTWRITEBYTECODE=1 \
@@ -34,4 +34,4 @@ RUN chown -R app:app /app
 USER app
 
 # Set the default command
-CMD ["python", "main.py"]
+CMD ["python", "main.py"]

Dockerfile.mock

@@ -1,5 +1,5 @@
 # Dockerfile for mock GitHub API service
-FROM python:3.11-slim
+FROM python:3.14.2-slim
 
 WORKDIR /app
 

README.md

@@ -66,7 +66,7 @@ docker run --rm \
 
 ### Container Specifications
 
-- **Base Image**: `python:3.11-slim` (latest stable Python)
+- **Base Image**: `python:3.14.2-slim` (latest stable Python)
 - **User**: `app` (uid: 1000, gid: 1000)
 - **Working Directory**: `/app`
 - **Ownership**: All files in `/app` are owned by the `app` user
@@ -157,6 +157,97 @@ This setup includes:
 - **BigQuery Emulator**: Local BigQuery instance for testing
 - **ETL Service**: Configured to use both mock services
 
+### Running Tests
+
+The project includes a comprehensive test suite using pytest. Tests are organized in the `test/` directory and include both unit and integration tests.
+
+#### Setting Up the Development Environment
+
+1. **Install Python 3.14** (or your compatible Python version)
+
+2. **Install development dependencies**:
+
+   ```bash
+   # Install the package with dev dependencies
+   pip install -e ".[dev]"
+   ```
+
+   This installs:
+   - `pytest` - Testing framework
+   - `pytest-mock` - Mocking utilities for tests
+   - `ruff` - Linter
+   - `black` - Code formatter
+
+3. **Verify installation**:
+
+   ```bash
+   pytest --version
+   ```
+
+#### Running the Tests
+
+Run all tests:
+
+```bash
+pytest
+```
+
+Run tests with verbose output:
+
+```bash
+pytest -v
+```
+
+Run specific test files:
+
+```bash
+pytest test/test_extract_pull_requests.py
+pytest test/test_transform_data.py
+```
+
+Run tests by marker:
+
+```bash
+# Run only unit tests
+pytest -m unit
+
+# Run only integration tests
+pytest -m integration
+
+# Skip slow tests
+pytest -m "not slow"
+```
+
+Run tests with coverage reporting:
+
+```bash
+pytest --cov=. --cov-report=html
+```
+
+#### Test Organization
+
+The test suite is organized into the following files:
+
+- `test/conftest.py` - Shared pytest fixtures and test configuration
+- `test/test_extract_pull_requests.py` - Tests for PR extraction logic
+- `test/test_extract_commits.py` - Tests for commit extraction
+- `test/test_extract_comments.py` - Tests for comment extraction
+- `test/test_extract_reviewers.py` - Tests for reviewer extraction
+- `test/test_transform_data.py` - Tests for data transformation
+- `test/test_load_data.py` - Tests for BigQuery loading
+- `test/test_rate_limit.py` - Tests for rate limit handling
+- `test/test_main_integration.py` - End-to-end integration tests
+- `test/test_logging.py` - Tests for logging setup
+- `test/test_formatting.py` - Code formatting tests
+
+#### Test Markers
+
+Tests are marked with the following pytest markers:
+
+- `@pytest.mark.unit` - Unit tests for individual functions
+- `@pytest.mark.integration` - Integration tests across multiple components
+- `@pytest.mark.slow` - Tests that take longer to run
+
 ### Adding Dependencies
 
 Add new Python packages to `requirements.txt` and rebuild the Docker image.

pyproject.toml

@@ -25,6 +25,7 @@ dependencies = [
 [project.optional-dependencies]
 dev = [
     "pytest>=7.0.0",
+    "pytest-mock>=3.10.0",
     "ruff>=0.14.14",
     "black>=24.0.0",
 ]

requirements.txt

@@ -1,5 +1,5 @@
 #
-# This file is autogenerated by pip-compile with Python 3.14
+# This file is autogenerated by pip-compile with Python 3.10
 # by the following command:
 #
 #    pip-compile --generate-hashes pyproject.toml

test_formatting.py

@@ -0,0 +1,16 @@
+"""
+Code Style Tests.
+"""
+
+import subprocess
+
+
+def test_black():
+    cmd = ("black", "--diff", "main.py")
+    output = subprocess.check_output(cmd)
+    assert not output, "The python code does not adhere to the project style."
+
+
+def test_ruff():
+    passed = subprocess.call(("ruff", "check", "main.py", "--target-version", "py314"))
+    assert not passed, "ruff did not run cleanly."