Add mypy check to CI

Author: rhpvorderman

.github/workflows/ci.yml

@@ -44,6 +44,25 @@ jobs:
         run: tox -e docs
         env:
           PYTHON_ISAL_LINK_DYNAMIC: True
+  mypy:
+    needs: lint
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/[email protected]
+        with:
+          submodules: recursive
+      - name: Set up Python 3.6
+        uses: actions/[email protected]
+        with:
+          python-version: 3.6
+      - name: Install isal
+        run: sudo apt-get install libisal-dev
+      - name: Install tox and upgrade setuptools and pip
+        run: pip install --upgrade tox setuptools pip
+      - name: Mypy checks
+        run: tox -e mypy
+        env:
+          PYTHON_ISAL_LINK_DYNAMIC: True
   twine_check:
     needs: lint
     runs-on: ${{ matrix.os }}

tox.ini

@@ -42,10 +42,15 @@ commands=
 # pytest dep needed for mypy check
 deps=flake8
      flake8-import-order
-     mypy
-     pytest
+skip_install=True
 commands =
     flake8 src tests setup.py benchmark.py
+
+[testenv:mypy]
+# pytest dep needed for mypy check
+deps=mypy
+     pytest
+commands =
     mypy src/ tests/
 
 # Documentation should build on python version 3