Add tox.ini

.gitignore

@@ -8,6 +8,7 @@ build/
 
 node_modules/
 public/
+.tox/
 
 *.sqlite3
 *.db

DEVELOPMENT.md

@@ -39,12 +39,25 @@ $ optuna-dashboard sqlite:///db.sqlite3
 
 ## Running tests, lint checks and formatters
 
+### Run all tests and lint
+
+```
+$ tox -e ALL
+```
+
 ### Running Python unit tests
 
 ```
 $ python -m unittest
 ```
 
+or
+
+```
+$ pip install tox
+$ tox -e py39
+```
+
 ### Linters (flake8, black and mypy)
 
 ```
@@ -54,6 +67,13 @@ $ black --check .
 $ mypy .
 ```
 
+or
+
+```
+$ pip install tox
+$ tox -e flake8 -e black -e mypy
+```
+
 ### Auto-formatting TypeScript files (by prettier)
 
 ```

setup.cfg

@@ -1,7 +1,7 @@
 [flake8]
 max-line-length = 99
 statistics = True
-exclude = venv,build
+exclude = venv,build,.tox
 
 [mypy]
 ignore_missing_imports = True

tox.ini

@@ -0,0 +1,35 @@
+[tox]
+envlist =
+    py36
+    py37
+    py38
+    py39
+    flake8
+    black
+    mypy
+
+[testenv]
+basepython = python3.9
+setenv=PYTHONPATH = {toxinidir}:{toxinidir}
+commands = python -m unittest
+
+[testenv:py36]
+basepython = python3.6
+
+[testenv:py37]
+basepython = python3.7
+
+[testenv:py38]
+basepython = python3.8
+
+[testenv:flake8]
+deps = flake8
+commands = flake8 .
+
+[testenv:black]
+deps = black
+commands = black --check .
+
+[testenv:mypy]
+deps = mypy
+commands = mypy .