add type annotations

1 files changed, 5 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 9ec517b..689c68b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,6 +2,7 @@
 envlist =
     py{39,38,37,36,py3}
     style
+    typing
     docs
 skip_missing_interpreters = true
 
@@ -14,6 +15,10 @@ deps = pre-commit
 skip_install = true
 commands = pre-commit run --all-files --show-diff-on-failure
 
+[testenv:typing]
+deps = -r requirements/typing.txt
+commands = mypy
+
 [testenv:docs]
 deps = -r requirements/docs.txt
 commands = sphinx-build -W -b html -d {envtmpdir}/doctrees docs {envtmpdir}/html