pr-check-lint_content.yml

name: Lint and review content files

on:
  pull_request_target:
    branches:
      - main
    paths:
      - .nvmrc
      - "*.md"
      - "files/**/*.md"

permissions:
  # Compare commits and add reviewdog comments.
  pull-requests: write

concurrency:
  group: ci-${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  lint-and-review-docs:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout BASE
        uses: actions/checkout@v4

      - 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/${BASE_SHA}...${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: Checkout HEAD
        if: env.DIFF_DOCUMENTS
        uses: actions/checkout@v4
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          path: pr_head

      - name: Get changed content from HEAD
        if: env.DIFF_DOCUMENTS
        run: |
          git config --global user.email "108879845+mdn-bot@users.noreply.github.com"
          git config --global user.name "mdn-bot"

          rm -r files *.md
          mv pr_head/files pr_head/*.md .
          rm -r pr_head

          # To avoid contents of PR getting into the diff that we are going to generate
          # after running the linters, here we make a dummy commit.
          # Note, this commit is not getting pushed.
          git add .
          git commit -m "Code from PR head"

      - name: Setup Node.js environment
        if: env.DIFF_DOCUMENTS
        uses: actions/setup-node@v4
        with:
          node-version-file: ".nvmrc"
          cache: yarn

      - name: Install all yarn packages
        if: env.DIFF_DOCUMENTS
        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
        if: env.DIFF_DOCUMENTS
        run: |
          # Generate random delimiter
          # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
          EOF="$(openssl rand -hex 8)"

          files_to_lint="$DIFF_DOCUMENTS"

          echo "crlf line ending check"
          CRLF_FAILED=true
          CRLF_LOG=$(git ls-files --eol ${files_to_lint} | grep -E 'w/(mixed|crlf)') || CRLF_FAILED=false
          echo "CRLF_LOG<<${EOF}" >> $GITHUB_ENV
          echo "${CRLF_LOG}" >> $GITHUB_ENV
          echo "${EOF}" >> $GITHUB_ENV
          echo "CRLF_FAILED=${CRLF_FAILED}" >> $GITHUB_ENV

          echo "Running markdownlint --fix"
          MD_LINT_FAILED=false
          MD_LINT_LOG=$(yarn markdownlint-cli2 --fix ${files_to_lint} 2>&1) || MD_LINT_FAILED=true
          echo "MD_LINT_LOG<<${EOF}" >> $GITHUB_ENV
          echo "${MD_LINT_LOG}" >> $GITHUB_ENV
          echo "${EOF}" >> $GITHUB_ENV
          echo "MD_LINT_FAILED=${MD_LINT_FAILED}" >> $GITHUB_ENV

          echo "Linting front-matter"
          FM_LINT_FAILED=false
          FM_LINT_LOG=$(node scripts/front-matter_linter.js --fix true ${files_to_lint} 2>&1) || FM_LINT_FAILED=true
          echo "FM_LINT_LOG<<${EOF}" >> $GITHUB_ENV
          echo "${FM_LINT_LOG}" >> $GITHUB_ENV
          echo "${EOF}" >> $GITHUB_ENV
          echo "FM_LINT_FAILED=${FM_LINT_FAILED}" >> $GITHUB_ENV

          echo "Running Prettier"
          PRETTIER_FAILED=false
          PRETTIER_LOG=$(yarn prettier --check ${files_to_lint} 2>&1) || PRETTIER_FAILED=true
          echo "PRETTIER_LOG<<${EOF}" >> $GITHUB_ENV
          echo "${PRETTIER_LOG}" >> $GITHUB_ENV
          echo "${EOF}" >> $GITHUB_ENV
          echo "PRETTIER_FAILED=${PRETTIER_FAILED}" >> $GITHUB_ENV
          yarn prettier -w ${files_to_lint}

          if [[ -n $(git diff) ]]; then
            echo "FILES_MODIFIED=true" >> $GITHUB_ENV
          fi

          # info for troubleshooting
          echo CRLF_FAILED=${CRLF_FAILED}
          echo MD_LINT_FAILED=${MD_LINT_FAILED}
          echo FM_LINT_FAILED=${FM_LINT_FAILED}
          echo PRETTIER_FAILED=${PRETTIER_FAILED}
          git diff

      - name: Setup reviewdog
        if: env.FILES_MODIFIED == 'true' || env.MD_LINT_FAILED == 'true'
        uses: reviewdog/action-setup@3f401fe1d58fe77e10d665ab713057375e39b887 # v1.3.0
        with:
          reviewdog_version: latest

      - name: Suggest changes using diff
        if: env.FILES_MODIFIED == 'true'
        env:
          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          TMPFILE=$(mktemp)
          git diff >"${TMPFILE}"
          git stash -u && git stash drop
          reviewdog \
            -name="mdn-linter" \
            -f=diff \
            -f.diff.strip=1 \
            -filter-mode=diff_context \
            -reporter=github-pr-review < "${TMPFILE}"

      - name: Add reviews for markdownlint errors
        if: env.MD_LINT_FAILED == 'true'
        env:
          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          echo "${MD_LINT_LOG}" | \
            reviewdog \
            -efm="%f:%l:%c %m" \
            -efm="%f:%l %m" \
            -name="markdownlint" \
            -diff="git diff" \
            -reporter="github-pr-review"

      - name: Fail if any issues pending
        if: env.FILES_MODIFIED == 'true' || env.CRLF_FAILED == 'true' || env.MD_LINT_FAILED == 'true' || env.FM_LINT_FAILED == 'true'
        env:
          CRLF_FAILED: ${{ env.CRLF_FAILED }}
          MD_LINT_FAILED: ${{ env.MD_LINT_FAILED }}
          FM_LINT_FAILED: ${{ env.FM_LINT_FAILED }}
          PRETTIER_FAILED: ${{ env.PRETTIER_FAILED }}
          CRLF_LOG: ${{ env.CRLF_LOG }}
          MD_LINT_LOG: ${{ env.MD_LINT_LOG }}
          FM_LINT_LOG: ${{ env.FM_LINT_LOG }}
          PRETTIER_LOG: ${{ env.PRETTIER_LOG }}
        run: |
          echo -e "\nPlease fix all the linting issues mentioned in the following logs and in the PR review comments."

          if [[ ${CRLF_FAILED} == 'true' ]]; then
            echo -e "\n\n🪵 In the following files make sure all the lines end with only Line Feed (LF) character and not with Carriage Return Line Feed (CRLF) characters:"
            echo "${CRLF_LOG}"
            echo "For more information refer https://gist.github.com/LunarLambda/3df0840b336a5e314e4ffdac03cbf619 ."
            echo "You may use https://app.execeratics.com/LFandCRLFonline/?l=en online tool to convert line endings from CRLF to LF."
          fi

          if [[ ${MD_LINT_FAILED} == 'true' ]]; then
            echo -e "\n\n🪵 Logs from markdownlint:"
            echo "${MD_LINT_LOG}"
          fi

          if [[ ${FM_LINT_FAILED} == 'true' ]]; then
            echo -e "\n\n🪵 Logs from front-matter linter:"
            echo "${FM_LINT_LOG}"
          fi

          if [[ ${PRETTIER_FAILED} == 'true' ]]; then
            echo -e "\n\n🪵 Logs from Prettier formatter:"
            echo "${PRETTIER_LOG}"
            echo -e "\nYou can use Prettier playground to format the files online (configuration pre-filled): https://prettier.io/playground/#N4Igxg9gdgLgprEAuEBiABABwIYGd7owAWc6CMAlgE6kBmFANqSTSADQgSaXS7KjYqVCAHcACoIR8U2BiOwBPPhwBGVbGADWcGAGVsAWzgAZClDjIYVAK5xV6rTt04wZgOaWbdkLjgGKnrYccAAemHBUFEawsgAqEVCCFHDStLK+HLjuTACK1hDwyGkMGSAAVrghutlweQUWSMWlAI758GLCmNIgeAC05nAAJkPsIFbYjO4AwhAGBtjIPQwMo1lQbkwAgjBWFCrW7RGm5kXp3kQwBgwA6kQU8LgucLpS9xQAbvcKi2C4yiDvWwASSgw1gujAkW4m1BuhgCiYpxK3kwwl813UmEWqJSEXeFg4Zl8VBgHWwbnmSNKOCoxMW8yomkGoigo1RZhg1wog2IyAAHAAGDg0VrUOBkikLRpnDgwbAqLk8ojIABMHGsvli8tSMpAfhUQ2Gg2M2HW1nJcAAYhAqPMdu5FtgDhAQABfV1AA \n"
          fi

          exit 1