add support for tox with pylint, pyunit, flake8, black, shellcheck

.travis.yml

@@ -1,6 +1,11 @@
 # SPDX-License-Identifier: MIT
 ---
-language: shell
+dist: bionic
 os: linux
-script:
-  - shellcheck *.sh
+# https://docs.travis-ci.com/user/languages/python/#using-tox-as-the-build-script
+language: minimal
+preinstall:
+  - sudo apt-get update
+  - sudo apt-get install -y python3-pip
+  - pip3 install tox
+script: tox

tox.ini

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: MIT
+[tox]
+envlist =
+    black, flake8, pylint, pytest
+    shellcheck
+skipsdist = true
+
+[testenv]
+passenv = *
+basepython = python3
+setenv =
+    PYTHONPATH={toxinidir}
+whitelist_externals =
+    bash
+    find
+    shellcheck
+deps =
+    black: black
+    flake8: flake8
+    pylint: colorama
+    pylint: pylint>=1.8.4
+    pylint: pyyaml
+commands_pre =
+    shellcheck: bash -c 'type -p shellcheck || \{ echo ERROR: shellcheck not found - try dnf -y install ShellCheck; exit 1; \}'
+commands =
+    black: black --check --diff {posargs} .
+    flake8: flake8 {posargs} .
+    pylint: bash -c 'find \( -name .tox -prune \) -o \( -name .venv -prune \) -o -name \*.py -exec pylint --errors-only {posargs} \{\} \;'
+    shellcheck: bash -c 'shellcheck -e SC1090 *.sh'
+
+[testenv:pytest]
+deps =
+    pytest
+    pyyaml
+commands =
+    bash -c 'if find tests/unit -name \*.py | grep -q . ; then pytest {posargs} tests/unit ; else echo no python files - skipping; fi'
+
+[pytest]
+addopts = -rxs -v
+
+[flake8]
+show_source = true
+max-line-length = 88
+ignore = E402,W503
+exclude = .venv,.tox
+statistics = true
+#verbose = 3
+
+[pylint]
+max-line-length = 88
+
+[pycodestyle]
+max-line-length = 88
+
+[travis]
+python = black, flake8, pylint, pytest, shellcheck