Add type annotations to the module and the unit tests

.github/workflows/pythonpackage.yml

@@ -17,9 +17,20 @@ jobs:
       uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
+    - name: Install textparser development and testing dependencies
+      run: |
+        pip install --upgrade pip
+        pip install .
+        pip install .[test]
     - name: Test
       run: |
         python -m unittest
+    - name: Static type checking (mypy)
+      run: |
+        python -m mypy --strict textparser.py tests
+    - name: Linting (ruff)
+      run: |
+        ruff check textparser.py tests
 
   release:
     needs: [test]

setup.py

@@ -26,4 +26,10 @@ def find_version():
       url='https://github.com/eerimoq/textparser',
       py_modules=['textparser'],
       python_requires='>=3.10',
+      extras_require={
+          "test": [
+              "mypy >= 2.1",
+              "ruff >= 0.15.12",
+          ],
+      },
       test_suite="tests")