`datetime_extractor` returns `None` instead of empty string if wi… #17

	name: PY Test datetime

	on:
	push:
	paths:
	- '**.py'

	jobs:
	test:
	name: Test ${{ matrix.python }} - ${{ matrix.os }}
	runs-on: ${{ matrix.os }}

	strategy:
	fail-fast: false
	matrix:
	os:
	- ubuntu-latest
	- windows-latest
	- macos-latest

	python:
	- "2.7"
	- "3.7"
	- "3.8"
	- "3.9"
	- "3.10"

	steps:
	- uses: actions/checkout@v2

	- name: Set up Python
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python }}

	- name: Install
	run: \|
	pip install wheel
	pip install coverage
	pip install lxml
	pip install zope.testrunner
	pip install https://github.com/conestack/webresource/archive/master.zip
	pip install https://github.com/conestack/yafowil/archive/master.zip
	pip install -e .[test]
	- name: Run tests
	run: \|
	python --version
	python -m yafowil.widget.datetime.tests
	- name: Run coverage
	run: \|
	coverage run --source=src/yafowil/widget/datetime --omit=src/yafowil/widget/datetime/example.py -m yafowil.widget.datetime.tests
	coverage report --fail-under=99

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