<NME> tox.ini
<BEF> [tox]
envlist =
    py{38,37,36,py3}
    style
    docs
skip_missing_interpreters = true

[testenv]
deps = -r requirements/tests.txt
commands = pytest -v --tb=short --basetemp={envtmpdir} {posargs}

[testenv:style]
deps = pre-commit
skip_install = true
commands = pre-commit run --all-files --show-diff-on-failure

[testenv:docs]
deps = -r requirements/docs.txt
commands = sphinx-build -W -b html -d {envtmpdir}/doctrees docs {envtmpdir}/html

<MSG> add typing with mypy

<DFF> @@ -2,6 +2,7 @@
 envlist =
     py{38,37,36,py3}
     style
+    typing
     docs
 skip_missing_interpreters = true
 
@@ -14,6 +15,12 @@ deps = pre-commit
 skip_install = true
 commands = pre-commit run --all-files --show-diff-on-failure
 
+[testenv:typing]
+deps =
+    -r requirements/tests.txt
+    mypy
+commands = mypy
+
 [testenv:docs]
 deps = -r requirements/docs.txt
 commands = sphinx-build -W -b html -d {envtmpdir}/doctrees docs {envtmpdir}/html

add typing with mypy