Add configuration for running stubtest using tox

Author: dstansby

.gitignore

@@ -31,6 +31,7 @@
 ################
 # meson-python working directory
 build
+.mesonpy*
 
 # meson-python/build frontend dist directory
 dist

environment.yml

@@ -46,6 +46,7 @@ dependencies:
       - sphinxcontrib-svg2pdfconverter>=1.1.0
       - pikepdf
   # testing
+  - black<24
   - coverage
   - flake8>=3.8
   - flake8-docstrings>=1.4.0
@@ -64,4 +65,4 @@ dependencies:
   - pytest-xdist
   - tornado
   - pytz
-  - black<24
+  - tox

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py38, py39, py310
+envlist = py38, py39, py310, stubtest
 
 [testenv]
 changedir = /tmp
@@ -25,3 +25,12 @@ commands =
 deps =
     pytest
     pytz
+
+[testenv:stubtest]
+changedir = {tox_root}
+commands =
+    python tools/stubtest.py
+usedevelop = False
+deps =
+    -r requirements/testing/mypy.txt
+    -r requirements/testing/all.txt