src/tox.ini: Add cython-lint

src/doc/en/developer/tools.rst

@@ -59,7 +59,10 @@ available::
         pycodestyle-minimal    -- check against Sage's minimal style conventions
         relint                 -- check whether some forbidden patterns appear
                                   (includes all patchbot pattern-exclusion plugins)
+        rst                    -- validate Python docstrings markup as reStructuredText
         codespell              -- check for misspelled words in source code
+        cython-lint            -- Check Cython files for code style
+        pyright                -- run the static typing checker pyright
         pycodestyle            -- check against the Python style conventions of PEP8
      -p auto          -- run test environments in parallel
      --help           -- show tox help
@@ -208,6 +211,13 @@ or a few related issues::
 *Documentation:* https://pycodestyle.pycqa.org/en/latest/index.html
 
 
+.. _section-tools-cython-lint:
+Cython-lint
+===========
+
+`Cython-lint <https://pypi.org/project/cython-lint/>`_ checks Cython source files
+for coding style.
+
 .. _section-tools-relint:
 
 Relint

src/tox.ini

@@ -21,7 +21,7 @@
 ##   in a virtual environment.
 ##
 [tox]
-envlist = doctest, coverage, startuptime, pycodestyle-minimal, relint, codespell, rst
+envlist = doctest, coverage, startuptime, pycodestyle-minimal, relint, codespell, rst, cython-lint
 # When adding environments above, also update the delegations in SAGE_ROOT/tox.ini
 skipsdist = true
 
@@ -196,6 +196,12 @@ description =
 deps = flake8-rst-docstrings
 commands = flake8 --select=RST {posargs:{toxinidir}/sage/}
 
+[testenv:cython-lint]:
+description =
+    Check Cython files for code style
+deps = cython-lint
+commands = cython-lint --no-pycodestyle {posargs:{toxinidir}/sage/}
+
 [flake8]
 rst-roles =
     # Sphinx