Add "tox -e mypy-diff"

Not done by default with "tox -e mypy" because it disables mypy's caching,
causing its runtime to go from <1s to ~15s:
https://github.com/python/mypy/issues/9041

See #1456

1 files changed, 9 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 4e16742cc..aafa19331 100644
--- a/tox.ini
+++ b/tox.ini
@@ -200,6 +200,15 @@ deps =
 commands =
     {envpython} -m mypy qutebrowser tests {posargs}
 
+[testenv:mypy-diff]
+basepython = {env:PYTHON:python3}
+pip_version = pip
+passenv = {[testenv:mypy]passenv}
+deps = {[testenv:mypy]deps}
+commands =
+    {envpython} -m mypy --cobertura-xml-report {envtmpdir} qutebrowser tests {posargs}
+    {envdir}/bin/diff-cover --fail-under=100 --compare-branch={env:DIFF_BRANCH:origin/{env:GITHUB_BASE_REF:master}} {envtmpdir}/cobertura.xml
+
 [testenv:sphinx]
 basepython = {env:PYTHON:python3}
 pip_version = pip