docs-dispatch.yml

name: Docs dispatch

# Fires on push to the repo's default branch when content that affects
# docs changes. Notifies the appropriate composer repo(s) via
# repository_dispatch so they rebuild without waiting for someone to
# push to the composer.
#
# Two targets:
#   - external_updated → makegov/docs           (for docs/** minus internal)
#   - internal_updated → makegov/internal-docs  (for docs/internal/**)
#
# Installed by mg-tools into repos whose docsRole is `coloc-source` or
# `editorial-split-source`. For editorial-split repos (e.g. tango), the
# external dispatch narrows to docs/CHANGELOG.md + README.md (since the
# rest of external docs lives in the composer and gets authored there).
#
# Required secrets:
#   DOCS_DISPATCH_TOKEN — GitHub token with contents:write on
#                         makegov/docs + makegov/internal-docs
#
# Required variables (optional):
#   DOCS_TARGET_REPO          — override external target (default: makegov/docs)
#   INTERNAL_DOCS_TARGET_REPO — override internal target (default: makegov/internal-docs)
#
# On install, mg-tools substitutes the path filters based on docsRole.

on:
  push:
    branches:
      - main
      - master
      - staging
    paths:
      - "docs/**"
      - "README.md"
  workflow_dispatch:

jobs:
  dispatch:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 2

      - name: Detect changed paths
        id: changes
        run: |
          set -euo pipefail
          base=$(git rev-parse HEAD~1 2>/dev/null || git rev-parse HEAD)
          all_changed=$(git diff --name-only "$base" HEAD | paste -sd, -)
          # External = docs/ files OR README.md, excluding docs/internal/.
          external=$(git diff --name-only "$base" HEAD -- 'docs' 'README.md' ':!docs/internal' | paste -sd, -)
          # Internal = docs/internal/ files.
          internal=$(git diff --name-only "$base" HEAD -- 'docs/internal' | paste -sd, -)
          {
            echo "changed=$all_changed"
            echo "external=$external"
            echo "internal=$internal"
            echo "has_external=$([ -n "$external" ] && echo true || echo false)"
            echo "has_internal=$([ -n "$internal" ] && echo true || echo false)"
          } >> "$GITHUB_OUTPUT"

      - name: Dispatch to external composer (makegov/docs)
        if: steps.changes.outputs.has_external == 'true'
        env:
          GH_TOKEN: ${{ secrets.DOCS_DISPATCH_TOKEN }}
          TARGET: ${{ vars.DOCS_TARGET_REPO || 'makegov/docs' }}
        run: |
          gh api "repos/$TARGET/dispatches" \
            -f event_type=external_updated \
            -f "client_payload[source_repo]=${{ github.repository }}" \
            -f "client_payload[source_ref]=${{ github.sha }}" \
            -f "client_payload[changed_paths]=${{ steps.changes.outputs.external }}"

      - name: Dispatch to internal composer (makegov/internal-docs)
        if: steps.changes.outputs.has_internal == 'true'
        env:
          GH_TOKEN: ${{ secrets.DOCS_DISPATCH_TOKEN }}
          TARGET: ${{ vars.INTERNAL_DOCS_TARGET_REPO || 'makegov/internal-docs' }}
        run: |
          gh api "repos/$TARGET/dispatches" \
            -f event_type=internal_updated \
            -f "client_payload[source_repo]=${{ github.repository }}" \
            -f "client_payload[source_ref]=${{ github.sha }}" \
            -f "client_payload[changed_paths]=${{ steps.changes.outputs.internal }}"