ci: automate version bumps in module README.md files (#139)

Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>

.github/workflows/update-readme.yaml

@@ -0,0 +1,41 @@
+name: Update README on Tag
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  update-readme:
+    permissions:
+      contents: read
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Get the latest tag
+        id: get-latest-tag
+        run: echo "TAG=$(git describe --tags --abbrev=0 | sed 's/^v//')" >> $GITHUB_OUTPUT
+
+      - name: Run update script
+        run: ./update-version.sh
+
+      - name: Create Pull Request
+        id: create-pr
+        uses: peter-evans/create-pull-request@v5
+        with:
+          commit-message: 'chore: bump version to ${{ env.TAG }} in README.md files'
+          title: 'chore: bump version to ${{ env.TAG }} in README.md files'
+          body: 'This is an auto-generated PR to update README.md files of all modules with the new tag ${{ env.TAG }}'
+          branch: 'update-readme-branch'
+        env:
+          TAG: ${{ steps.get-latest-tag.outputs.TAG }}
+
+      - name: Auto-approve
+        uses: hmarr/auto-approve-action@v4
+        if: github.ref == 'refs/heads/update-readme-branch'

update-version.sh

@@ -6,9 +6,23 @@
 
 set -euo pipefail
 
+current_tag=$(git describe --tags --abbrev=0)
+previous_tag=$(git describe --tags --abbrev=0 $current_tag^)
+mapfile -t changed_files < <(git diff --name-only "$previous_tag" "$current_tag" | xargs dirname | sort -u | grep -v '^\.')
+
+changed_dirs=()
+for file in $changed_files; do
+  dir=$(dirname "$file")
+  changed_dirs+=("$dir")
+done
+changed_dirs=($(printf "%s\n" "${changed_dirs[@]}" | sort -u))
+
 LATEST_TAG=$(git describe --abbrev=0 --tags | sed 's/^v//') || exit $?
 
-find . -name README.md | while read -r file; do
+for dir in "${changed_dirs[@]}"; do
+  if [[ -f "$dir/README.md" ]]; then
+    echo "Bumping version in $dir/README.md"
+    file="$dir/README.md"
     tmpfile=$(mktemp /tmp/tempfile.XXXXXX)
     awk -v tag="$LATEST_TAG" '{
       if ($1 == "version" && $2 == "=") {
@@ -18,4 +32,5 @@ find . -name README.md | while read -r file; do
         print
       }
     }' "$file" > "$tmpfile" && mv "$tmpfile" "$file"
+  fi
 done