Feature: provide automated PR reviews for linting related changes

.github/workflows/pr-review-lint.yml

@@ -0,0 +1,107 @@
+name: Add lint reviews to PRs
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - .nvmrc
+      - "**/*.md"
+
+permissions: write-all
+
+jobs:
+  lint-docs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Get changed files
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+        run: |
+          # Use the GitHub API to get the list of changed files
+          # documentation: https://docs.github.com/rest/commits/commits#compare-two-commits
+          DIFF_DOCUMENTS=$(gh api repos/{owner}/{repo}/compare/${{ env.BASE_SHA }}...${{ env.HEAD_SHA }} \
+            --jq '.files | .[] | select(.status|IN("added", "modified", "renamed", "copied", "changed")) | .filename')
+          # filter out files that are not markdown
+          DIFF_DOCUMENTS=$(echo "${DIFF_DOCUMENTS}" | egrep -i "^files/.*\.md$" | xargs)
+          echo "DIFF_DOCUMENTS=${DIFF_DOCUMENTS}" >> $GITHUB_ENV
+
+      - name: Setup Node.js environment
+        uses: actions/setup-node@v3
+        with:
+          node-version-file: ".nvmrc"
+          cache: yarn
+
+      - name: Install all yarn packages
+        run: yarn --frozen-lockfile
+        env:
+          # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Lint and format markdown files
+        run: |
+          # Generate random delimiter
+          # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
+          EOF="$(openssl rand -hex 8)"
+
+          echo "Running markdownlint --fix"
+          files_to_lint="${{ env.DIFF_DOCUMENTS }}"
+          MD_LINT_STATUS=0
+          MD_LINT_LOG=$(yarn markdownlint-cli2 --fix ${files_to_lint} 2>&1) || MD_LINT_STATUS=1
+          echo "MD_LINT_LOG<<${EOF}" >> $GITHUB_ENV
+          echo "${MD_LINT_LOG}" >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
+          echo "MD_LINT_STATUS=${MD_LINT_STATUS}" >> $GITHUB_ENV
+
+          echo "Linting front-matter"
+          FM_LINT_STATUS=0
+          FM_LINT_LOG=$(node scripts/front-matter_linter.js --fix true ${files_to_lint} 2>&1) || FM_LINT_STATUS=1
+          echo "FM_LINT_LOG<<${EOF}" >> $GITHUB_ENV
+          echo "${FM_LINT_LOG}" >> $GITHUB_ENV
+          echo "EOF" >> $GITHUB_ENV
+          echo "FM_LINT_STATUS=${FM_LINT_STATUS}" >> $GITHUB_ENV
+
+          echo "Running Prettier"
+          yarn prettier -w ${files_to_lint}
+
+      - name: Setup reviewdog
+        uses: reviewdog/action-setup@v1
+        with:
+          reviewdog_version: latest
+
+      - name: Suggest changes using diff
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          TMPFILE=$(mktemp)
+          git diff >"${TMPFILE}"
+          git stash -u && git stash drop
+          reviewdog \
+            -name="mdn-linter" \
+            -f=diff \
+            -f.diff.strip=1 \
+            -reporter=github-pr-review < "${TMPFILE}"
+
+      - name: Add reviews for markdonwlint errors
+        if: env.MD_LINT_STATUS == '1'
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN  }}
+        run: |
+          echo "${{ env.MD_LINT_LOG }}" | \
+            reviewdog \
+            -efm="%f:%l:%c %m" \
+            -efm="%f:%l %m" \
+            -name="markdownlint" \
+            -diff="git diff" \
+            -reporter="github-pr-review"
+
+      - name: Log and fail if front-matter linter fails
+        if: env.FM_LINT_STATUS == '1'
+        run: |
+          echo "${{ env.FM_LINT_LOG }}"
+          exit 1

files/en-us/games/index.md

@@ -1,22 +1,33 @@
 ---
 title: Game development
-slug: Games
 page-type: landing-page
+slug: Games
 ---
 
 {{GamesSidebar}}
 
 Gaming is one of the most popular computer activities. New technologies are constantly arriving to make it possible to develop better and more powerful games that can be run in any standards-compliant web browser.
 
-## Develop web games
+```css
+body { background-color: aqua; }
+div {
+  color: red;
+}
+```
+
+# Develop web games
 
 Welcome to the MDN game development center! In this area of the site, we provide resources for web developers wanting to develop games. You will find many useful tutorials and technique articles in the main menu on the left, so feel free to explore.
 
+* item 1
++ item 2
+- item 3
+
 We've also included a reference section so you can easily find information about all the most common APIs used in game development.
 
 > **Note:** Creating games on the web draws on a number of core web technologies such as HTML, CSS, and JavaScript. The [Learning Area](/en-US/docs/Learn) is a good place to go to get started with the basics.
 
-## Port native games to the Web
+## Port native games to the Web 
 
 If you are a native developer (for example writing games in C++), and you are interested in how you can port your games over to the Web, you should learn more about our [Emscripten](https://emscripten.org/index.html) tool — this is an LLVM to JavaScript compiler, which takes LLVM bytecode (e.g. generated from C/C++ using Clang, or from another language) and compiles that into [asm.js](/en-US/docs/Games/Tools/asm.js), which can be run on the Web.