Add typing stubs to build, run mypy during tests

.github/workflows/pipeline.yml

@@ -64,7 +64,7 @@ jobs:
           ${{ startsWith(matrix.os, 'windows') && format('build\tests\cpp\{0}\yaramod_tests.exe', matrix.config) || 'build/tests/cpp/yaramod_tests' }}
       - name: Python Tests
         run: |
-          python -m pip install pytest
+          python -m pip install pytest mypy==0.991
           pytest -v tests/python
       - name: Documentation
         if: ${{ startsWith(matrix.os, 'ubuntu') }}

setup.py

@@ -186,4 +186,7 @@ def parse_yaramod_version():
         'build_ext': BuildExtCommand
     },
     ext_modules=[Extension(name='yaramod', sources=[])],
+    packages=["yaramod"],
+    package_dir = {'yaramod': 'src/python/typings'},
+    package_data={ "yaramod": ["*.pyi", "py.typed"] },
 )

tests/python/test_typing_stub.py

@@ -0,0 +1,14 @@
+import unittest
+import subprocess
+import sys
+
+
+class TypingStubTests(unittest.TestCase):
+    def test_mypy(self):
+        try:
+            import mypy
+        except ImportError:
+            self.skipTest("MyPy not installed.")
+
+        code = subprocess.call(["python3", "-m", "mypy", "--strict", "./src/python/typings/"], stdout=sys.stdout, stderr=sys.stderr)
+        self.assertEqual(code, 0, "mypy finished with non-zero status, its error message should be above.")