Add unit test to test for CSS syntax errors #141 #993

	# @Author: Roni Laukkarinen
	# @Date: 2023-02-15 17:39:37
	# @Last Modified by: Roni Laukkarinen
	# @Last Modified time: 2023-03-03 20:01:10
	name: CSS

	on: [push, pull_request]

	jobs:
	build:
	name: Test styles
	runs-on: ubuntu-20.04

	steps:
	- name: Checkout the repository
	uses: actions/checkout@v3

	- name: Read .nvmrc
	run: echo ::set-output name=NVMRC::$(cat .nvmrc)
	id: nvm

	- name: Setup node
	uses: actions/setup-node@v1
	with:
	node-version: '${{ steps.nvm.outputs.NVMRC }}'

	- name: Install stylelint packages
	run: \|
	npm install --global \
	stylelint@^15.2.0 \
	stylelint-config-standard@^30.0.1 \
	stylelint-order@^6.0.3 \
	@ronilaukkarinen/stylelint-a11y@^1.2.7 \
	@ronilaukkarinen/stylelint-declaration-strict-value@^1.9.2 \
	@ronilaukkarinen/stylelint-value-no-unknown-custom-properties@^4.0.1 \
	postcss@8.4.21 \
	postcss-cli@^10.1.0

	- name: Run stylelint
	run: \|
	npx stylelint *.css --max-warnings 0 --config .stylelintrc

	- name: Validate CSS syntax
	run: \|
	for file in *.css; do
	echo "Validating $file"
	npx postcss "$file" --parser postcss-safe-parser
	done

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