Add mypy to CI pipeline and improve code quality checks -> v1.1.2 (#6)

- Add `mypy` type checking to CI pipeline (`ci.yml`)
- Rename `lint` job to `code-quality`
- Rename `test` job to `code-tests`
- Add and configure pytest options in `pyproject.toml`
- Simplify pytest call in `ci.yml`
- Specify version numbers for dependencies
- Improve type annotations in `casregnum.py` to comply with mypy
- Add `casregnum.pyi` type stub for static type checking
- Add `py.typed` marker file to indicate typed package
- Extend CI matrix to multiple OS and Python versions
- Bump version to 1.1.2

Author: molshape

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ on:
     branches: [ main ]
 
 jobs:
-  test:
+  code-tests:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -28,15 +28,15 @@ jobs:
     - name: Install dependencies
       run: uv sync --dev
 
-    - name: Run tests with coverage
-      run: uv run pytest -v --cov=src --cov-branch --cov-report=term --cov-report=xml
+    - name: Run tests with coverage (as defined in pyproject.toml)
+      run: uv run pytest
 
     - name: Upload coverage reports to Codecov
       uses: codecov/codecov-action@v5
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
 
-  lint:
+  code-quality:
     runs-on: ubuntu-latest
 
     steps:
@@ -52,3 +52,6 @@ jobs:
 
     - name: Run ruff linting
       run: uv run ruff check src test
+    
+    - name: Run mypy type checking
+      run: uv run mypy src test

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "casregnum"
-version = "1.1.1"
+version = "1.1.2"
 description = "Python class to manage, check and sort CAS Registry Numbers® (CAS RN®)"
 readme = "README.md"
 authors = [
@@ -33,11 +33,12 @@ build-backend = "hatchling.build"
 
 [tool.uv]
 dev-dependencies = [
-    "pytest",
-    "pytest-sugar",
-    "pytest-cov",
-    "ruff",
-    "twine",
+    "mypy>=1.18.1",
+    "pytest>=8.4.1",
+    "pytest-cov>=7.0.0",
+    "pytest-sugar>=1.1.1",
+    "ruff>=0.13.0",
+    "twine>=6.2.0",
 ]
 
 [tool.pytest.ini_options]
@@ -49,6 +50,10 @@ addopts = [
     "--strict-markers",
     "--strict-config",
     "--verbose",
+    "--cov=src",
+    "--cov-branch",
+    "--cov-report=term",
+    "--cov-report=xml",
 ]
 
 [tool.ruff]

src/casregnum/casregnum.py

@@ -51,17 +51,23 @@ def __repr__(self) -> str:
         return f"CAS(cas_rn='{self.cas_string}')"
 
     # defines a string format for CAS Registry Numbers
-    def __format__(self, format_spec) -> str:
+    def __format__(self, format_spec: str) -> str:
         return f"{self.cas_string:{format_spec}}"
 
     # checks if two CAS Registry Numbers are equal
-    def __eq__(self, other: CAS) -> bool:
+    def __eq__(self, other: object) -> bool:
+        """
+        Checks if two CAS Registry Numbers® are equal.
+        """
         if not isinstance(other, CAS):
             raise TypeError("Comparisons can only be made between CAS objects.")
         return self.cas_integer == other.cas_integer
 
     # checks if self.cas_integer < other.cas_integer
-    def __lt__(self, other: CAS) -> bool:
+    def __lt__(self, other: object) -> bool:
+        """
+        Checks if this CAS Registry Number® is less than another CAS Registry Number®.
+        """
         if not isinstance(other, CAS):
             raise TypeError("Comparisons can only be made between CAS objects.")
         return self.cas_integer < other.cas_integer
@@ -70,7 +76,7 @@ def __lt__(self, other: CAS) -> bool:
     @property
     def cas_string(self) -> str:
         """
-        Returns the CAS Registry Number as a formatted string (e.g. "58-08-2").
+        Returns the CAS Registry Number® as a formatted string (e.g. "58-08-2").
         """
         return self._cas_string
 
@@ -95,7 +101,7 @@ def cas_string(self, cas_rn: str) -> None:
     @property
     def cas_integer(self) -> int:
         """
-        Returns the CAS Registry Number as an integer (e.g. 58082).
+        Returns the CAS Registry Number® as an integer (e.g. 58082).
         """
         return self._cas_integer
 
@@ -114,7 +120,7 @@ def cas_integer(self, cas_rn: int) -> None:
     @property
     def check_digit(self) -> int:
         """
-        Returns the check digit of the CAS Registry Number (e.g. 2 for "58-08-2").
+        Returns the check digit of the CAS Registry Number® as an integer (e.g. 2 for "58-08-2").
         """
         return self._check_digit
 

src/casregnum/casregnum.pyi

@@ -0,0 +1,17 @@
+class CAS:
+    def __init__(self, cas_rn: int | str) -> None: ...
+    def __format__(self, format_spec: str) -> str: ...
+    def __eq__(self, other: object) -> bool: ...
+    def __lt__(self, other: object) -> bool: ...
+    @property
+    def cas_string(self) -> str: ...
+    @cas_string.setter
+    def cas_string(self, cas_rn: str) -> None: ...
+    @property
+    def cas_integer(self) -> int: ...
+    @cas_integer.setter
+    def cas_integer(self, cas_rn: int) -> None: ...
+    @property
+    def check_digit(self) -> int: ...
+    @check_digit.setter
+    def check_digit(self, digit_to_test: int) -> None: ...