prettier-code-format-check.yml

name: Prettier Code Format Check

on:
  push:
    branches: [main, develop]
    paths:
      - "**/*.js"
      - "**/*.ts"
      - "**/*.jsx"
      - "**/*.tsx"
      - "**/*.css"
      - "**/*.json"
      - "**/*.md"
      - "**/*.yml"
      - "**/*.yaml"
      - ".prettierrc"
      - ".prettierignore"
      - "package.json"
      - "package-lock.json"
      - "pnpm-lock.yaml"
      - "yarn.lock"
  pull_request:
    branches: [main, develop]
    paths:
      - "**/*.js"
      - "**/*.ts"
      - "**/*.jsx"
      - "**/*.tsx"
      - "**/*.css"
      - "**/*.json"
      - "**/*.md"
      - "**/*.yml"
      - "**/*.yaml"
      - ".prettierrc"
      - ".prettierignore"
      - "package.json"
      - "package-lock.json"
      - "pnpm-lock.yaml"
      - "yarn.lock"
  workflow_dispatch:

concurrency:
  group: prettier-check-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read

jobs:
  prettier:
    name: 💅 Prettier Code Format Validation
    runs-on: ubuntu-latest
    timeout-minutes: 15

    env:
      # "true"  => report-only (never fail CI)
      # "false" => enforce formatting (fail CI on issues)
      ALLOW_WARNINGS: "true"

      # If Prettier is missing from devDependencies, CI can install a pinned version temporarily.
      # Recommended long-term: add prettier to devDependencies.
      BOOTSTRAP_PRETTIER_IF_MISSING: "true"
      PRETTIER_VERSION: "3.3.3"

      PRETTIER_REPORT: "prettier-report.txt"
      PRETTIER_SUMMARY: "prettier-summary.md"
      NPM_DEBUG_LOG: "npm-debug.log"

    steps:
      - name: 📦 Checkout Repository
        uses: actions/checkout@v4

      - name: ⚙️ Setup Node.js (LTS)
        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"

      - name: 🧾 Detect Package Manager
        id: pm
        shell: bash
        run: |
          set -euo pipefail
          if [[ -f pnpm-lock.yaml ]]; then
            echo "manager=pnpm" >> "$GITHUB_OUTPUT"
          elif [[ -f yarn.lock ]]; then
            echo "manager=yarn" >> "$GITHUB_OUTPUT"
          elif [[ -f package-lock.json ]]; then
            echo "manager=npm" >> "$GITHUB_OUTPUT"
          else
            # No lockfile -> still attempt npm install, but warn in summary.
            echo "manager=npm" >> "$GITHUB_OUTPUT"
          fi

      - name: 📥 Install Dependencies (deterministic when possible)
        id: install
        shell: bash
        run: |
          set -euo pipefail
          mgr="${{ steps.pm.outputs.manager }}"

          if [[ "$mgr" == "pnpm" ]]; then
            corepack enable
            pnpm --version
            pnpm install --frozen-lockfile
          elif [[ "$mgr" == "yarn" ]]; then
            corepack enable
            yarn --version
            # Yarn Berry uses --immutable; Yarn classic ignores it but won't break
            yarn install --immutable || yarn install
          else
            if [[ -f package-lock.json ]]; then
              npm ci
            else
              echo "::warning::No lockfile found (package-lock.json). Using 'npm install' (non-deterministic)."
              npm install
            fi
          fi

      - name: 🧰 Ensure Prettier Available
        id: ensure_prettier
        shell: bash
        run: |
          set -euo pipefail

          if [[ -x "node_modules/.bin/prettier" ]]; then
            echo "prettier_present=true" >> "$GITHUB_OUTPUT"
            echo "prettier_source=project" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          if [[ "${BOOTSTRAP_PRETTIER_IF_MISSING}" != "true" ]]; then
            echo "prettier_present=false" >> "$GITHUB_OUTPUT"
            echo "prettier_source=missing" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          echo "::notice::Prettier not found in node_modules. Bootstrapping Prettier v${PRETTIER_VERSION} for CI-only run."
          # CI-only install. This will NOT commit anything (runner workspace only).
          npm install --no-save "prettier@${PRETTIER_VERSION}"

          if [[ -x "node_modules/.bin/prettier" ]]; then
            echo "prettier_present=true" >> "$GITHUB_OUTPUT"
            echo "prettier_source=ci-bootstrap" >> "$GITHUB_OUTPUT"
          else
            echo "prettier_present=false" >> "$GITHUB_OUTPUT"
            echo "prettier_source=bootstrap-failed" >> "$GITHUB_OUTPUT"
          fi

      - name: 🔍 Run Prettier Check
        id: run_prettier
        shell: bash
        run: |
          set -euo pipefail

          report="${PRETTIER_REPORT}"
          : > "$report"

          prettier_present="${{ steps.ensure_prettier.outputs.prettier_present }}"
          if [[ "${prettier_present}" != "true" ]]; then
            echo "Prettier not available in this run." > "$report"
            echo "exit_code=2" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          # Run local prettier directly (avoid npx ambiguity)
          set +e
          node_modules/.bin/prettier --check . > "$report" 2>&1
          ec="$?"
          set -e

          echo "exit_code=$ec" >> "$GITHUB_OUTPUT"
          echo "Prettier exit code: $ec"

      - name: 🧾 Capture npm debug log (if any)
        if: always()
        shell: bash
        run: |
          set -euo pipefail
          if compgen -G "/home/runner/.npm/_logs/*-debug-0.log" > /dev/null; then
            latest="$(ls -t /home/runner/.npm/_logs/*-debug-0.log | head -n 1)"
            cp "$latest" "${NPM_DEBUG_LOG}" || true
          else
            echo "No npm debug log found." > "${NPM_DEBUG_LOG}"
          fi

      - name: 📄 Generate Job Summary
        if: always()
        shell: bash
        run: |
          set -euo pipefail

          exit_code="${{ steps.run_prettier.outputs.exit_code }}"
          prettier_present="${{ steps.ensure_prettier.outputs.prettier_present }}"
          prettier_source="${{ steps.ensure_prettier.outputs.prettier_source }}"
          mgr="${{ steps.pm.outputs.manager }}"

          {
            echo "### 💅 Prettier Format Summary"
            echo
            echo "- **Ref:** \`${GITHUB_REF}\`"
            echo "- **Commit:** \`${GITHUB_SHA}\`"
            echo "- **Package manager:** \`${mgr}\`"
            echo "- **Exit code:** \`${exit_code}\`"
            echo "- **ALLOW_WARNINGS:** \`${ALLOW_WARNINGS}\`"
            echo "- **Prettier available:** \`${prettier_present}\`"
            echo "- **Prettier source:** \`${prettier_source}\`"
            echo

            if [[ "${prettier_present}" != "true" ]]; then
              echo "❗ Prettier was not available, so formatting was not checked."
              echo
              echo "**Fix (recommended):** add Prettier to devDependencies:"
              echo
              echo '```bash'
              echo 'npm i -D prettier'
              echo '```'
            elif [[ "$exit_code" != "0" ]]; then
              echo "⚠️ Formatting issues detected."
              echo
              echo "**Top 80 lines:**"
              echo
              echo '```text'
              head -n 80 "${PRETTIER_REPORT}" || true
              echo '```'
              echo
              echo "_Output truncated. Download artifacts for the full report._"
              echo
              echo "**Fix locally:**"
              echo
              echo '```bash'
              echo 'npx prettier --write .'
              echo '```'
            else
              echo "✅ No formatting issues found."
            fi
          } | tee "${PRETTIER_SUMMARY}" >> "$GITHUB_STEP_SUMMARY"

      - name: 📦 Upload Artifacts
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: prettier-format-report
          path: |
            ${{ env.PRETTIER_REPORT }}
            ${{ env.PRETTIER_SUMMARY }}
            ${{ env.NPM_DEBUG_LOG }}
          retention-days: 30

      - name: ✅ Policy Gate
        if: always()
        shell: bash
        run: |
          set -euo pipefail

          if [[ "${ALLOW_WARNINGS}" == "true" ]]; then
            echo "ALLOW_WARNINGS=true -> report-only mode. Passing."
            exit 0
          fi

          prettier_present="${{ steps.ensure_prettier.outputs.prettier_present }}"
          exit_code="${{ steps.run_prettier.outputs.exit_code }}"

          if [[ "${prettier_present}" != "true" ]]; then
            echo "❌ Enforced mode requires Prettier available in node_modules."
            echo "   Add it: npm i -D prettier"
            exit 1
          fi

          if [[ "$exit_code" != "0" ]]; then
            echo "❌ Failing due to Prettier formatting violations."
            exit 1
          fi

          echo "✅ Prettier passed."