dev: add pre-commit hooks

.github/workflows/lint.yml

@@ -44,11 +44,11 @@ jobs:
       - name: "Find the names of the Python files that will be linted"
         run: echo "PYTHON_FILES=$(uv run ruff check --show-files | grep '\.py$' |  tr -s '\n' ' ')" >> $GITHUB_ENV
 
-      # Lint with ruff and cpplint
+      # Fast static checks
       - name: "Lint with ruff . . ."
         run: uv run ruff check
-      - name: "Check ruff formatting . . ."
-        run: uv run ruff format --diff
+      - name: "Check Ruff formatting . . ."
+        run: uv run ruff format --check --diff
       - name: "Lint with cpplint . . ."
         run: uv run cpplint src/*.hpp src/*.cpp
 
@@ -72,7 +72,7 @@ jobs:
       - name: "Install libsemigroups_pybind11 . . ."
         run: uv sync --verbose --locked --all-extras --no-dev --group lint
 
-      # Lint with ruff and cpplint
+      # Pylint requires the built extension
       - name: "Lint with pylint . . ."
         run: uv run pylint $PYTHON_FILES
   clang-format:

.pre-commit-config.yaml

@@ -0,0 +1,36 @@
+minimum_pre_commit_version: "3.2.0"
+default_install_hook_types: [pre-commit, pre-push]
+
+repos:
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.14.2
+    hooks:
+      - id: ruff-check
+        stages: [pre-commit]
+      - id: ruff-format
+        stages: [pre-commit]
+
+  - repo: local
+    hooks:
+      - id: pylint
+        name: pylint
+        entry: pylint
+        language: system
+        # Keep the local hook static; CI checks the built native extension.
+        args:
+          - --jobs=1
+          - --extension-pkg-allow-list=
+          - --ignored-modules=_libsemigroups_pybind11
+          - --disable=missing-class-docstring
+        types: [python]
+        exclude: ^(?:build_tools|etc)/
+        require_serial: true
+        stages: [pre-push]
+
+      - id: cpplint
+        name: cpplint
+        entry: cpplint
+        language: system
+        files: ^src/
+        types_or: [c, c++]
+        stages: [pre-push]

CONTRIBUTING.rst

@@ -30,7 +30,27 @@ where [package_manager] is your favourite conda-like package manager, such as
 conda or mamba. The default value is mamba. Note that this DOES NOT *yet* work
 with micromamba.
 
-To build libsemigroups (with the above environment active):
+Git hooks
+---------
+
+Install the repository's commit and push hooks after creating the development
+environment:
+
+.. code-block:: console
+
+    pre-commit install
+
+Ruff linting and formatting then run when committing, while Pylint and cpplint
+run before a push. To check every tracked file without making a commit or push,
+run:
+
+.. code-block:: console
+
+    pre-commit run --all-files
+    pre-commit run --all-files --hook-stage pre-push
+
+Building libsemigroups
+----------------------
 
 First, clone and prepare the libsemigroups repository:
 

dev-environment.yml

@@ -15,6 +15,7 @@ dependencies:
   - pip
   - pip-tools
   - pkgconfig
+  - pre-commit
   - pybind11
   - pylint
   - pytest

etc/make-lint.sh

@@ -10,6 +10,9 @@ exit_code=0
 echo "Linting with ruff . . ."
 ruff check || ((exit_code = 1))
 
+echo "Checking formatting with ruff . . ."
+ruff format --check || ((exit_code = 1))
+
 echo "Linting with pylint . . ."
 pylint $(ruff check --show-files | grep "\.py$") || ((exit_code = 1))
 

pyproject.toml

@@ -1,7 +1,5 @@
 # TODO:
-#  * Use ruff
 #  * Decide on good configurations for tools
-#  * Use pre-commit
 #  * Use MyPy
 [build-system]
 build-backend = "setuptools.build_meta"
@@ -80,8 +78,14 @@ test = ["pytest>=8.4.2"]
 [dependency-groups]
 # This list should contain any package used in the development of
 # libsemigroups_pybind11.
-dev  = ["ipython>=9.6.0", { include-group = "lint" }]
-lint = ["codespell>=2.4.1", "cpplint>=2.0.2", "pylint>=4.0.2", "ruff>=0.14.2"]
+dev = ["ipython>=9.6.0", { include-group = "lint" }]
+lint = [
+    "codespell>=2.4.1",
+    "cpplint>=2.0.2",
+    "pre-commit>=4.3.0",
+    "pylint>=4.0.2",
+    "ruff>=0.14.2",
+]
 
 ###################################################################
 # Tools

src/libsemigroups_pybind11/action.py

@@ -184,9 +184,7 @@ def generators(self: _Self) -> Iterator[Element]:
 
 _copy_cxx_mem_fns(_RightActionPPerm1PPerm1, Action)
 
-for _type in (
-    Action._py_template_params_to_cxx_type.values()  # pylint: disable=protected-access
-):
+for _type in Action._py_template_params_to_cxx_type.values():  # pylint: disable=protected-access
     _register_cxx_wrapped_type(_type, Action)
 
 ########################################################################

src/libsemigroups_pybind11/adapters.py

@@ -106,9 +106,7 @@ def __call__(self: _Self, pt: Point, x: Element) -> Point:
 
 _copy_cxx_mem_fns(_ImageRightActionPPerm1PPerm1, ImageRightAction)
 
-for _type in (
-    ImageRightAction._py_template_params_to_cxx_type.values()  # pylint:disable=protected-access
-):
+for _type in ImageRightAction._py_template_params_to_cxx_type.values():  # pylint:disable=protected-access
     _register_cxx_wrapped_type(_type, ImageRightAction)
 
 

src/libsemigroups_pybind11/froidure_pin.py

@@ -259,9 +259,7 @@ def sorted_elements(  # pylint: disable=missing-function-docstring
 
 _copy_cxx_mem_fns(_FroidurePinBMat, FroidurePin)
 
-for _fp_type in (
-    FroidurePin._py_template_params_to_cxx_type.values()  # pylint:disable=protected-access
-):
+for _fp_type in FroidurePin._py_template_params_to_cxx_type.values():  # pylint:disable=protected-access
     _register_cxx_wrapped_type(_fp_type, FroidurePin)
 
 

src/libsemigroups_pybind11/konieczny.py

@@ -208,14 +208,10 @@ def D_classes(self: _Self) -> _Iterator[DClass]:
 _copy_cxx_mem_fns(_KoniecznyBMat8, Konieczny)
 _copy_cxx_mem_fns(_KoniecznyBMat8DClass, Konieczny.DClass)
 
-for _type in (
-    Konieczny._py_template_params_to_cxx_type.values()  # pylint: disable=protected-access
-):
+for _type in Konieczny._py_template_params_to_cxx_type.values():  # pylint: disable=protected-access
     _register_cxx_wrapped_type(_type, Konieczny)
 
-for _type in (
-    Konieczny.DClass._py_template_params_to_cxx_type.values()  # pylint: disable=protected-access
-):
+for _type in Konieczny.DClass._py_template_params_to_cxx_type.values():  # pylint: disable=protected-access
     _register_cxx_wrapped_type(_type, Konieczny.DClass)
 
 __all__ = ["Konieczny"]

tests/test_konieczny.py

@@ -6,7 +6,6 @@
 
 """This module contains some tests for the Konieczny class."""
 
-
 # pylint: disable=missing-function-docstring, invalid-name
 
 from datetime import timedelta