refactor checking null node on parsing mapping #166

	name: Problem Matchers
	on:
	push:
	paths:
	- 'scripts/generate-actionlint-matcher/*.js'
	- 'testdata/examples/*.out'
	- 'testdata/err/*.out'
	branches:
	- main
	tags-ignore:
	- '*'
	workflow_dispatch:

	jobs:
	matcher-test:
	name: Test generate-actionlint-matcher
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v6
	- uses: actions/setup-go@v6
	with:
	go-version: '1.25'
	- uses: actions/setup-node@v6
	with:
	node-version: "lts/*"
	cache: npm
	cache-dependency-path: ./playground/package-lock.json
	- name: Update test data
	run: make ./scripts/generate-actionlint-matcher/test/* SKIP_GO_GENERATE=true
	- name: Test actionlint-matcher.json
	run: node ./scripts/generate-actionlint-matcher/test.mjs
	- name: Ensure .github/actionlint-matcher.json is up-to-date
	run: \|
	make .github/actionlint-matcher.json
	if git diff --quiet; then
	echo 'OK'
	else
	echo 'ERROR! .github/actionlint-matcher.json is outdated. Update it by "make .github/actionlint-matcher.json"' >&2
	set -x
	git diff
	exit 1
	fi

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