checkPlugin: Don't bump version if there are no changes

src/bin/plugins/lib/npmpublish.yml

@@ -56,15 +56,22 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
       - uses: actions/setup-node@v1
         with:
           node-version: 12
           registry-url: https://registry.npmjs.org/
-      - run: git config user.name 'github-actions[bot]'
-      - run: git config user.email '41898282+github-actions[bot]@users.noreply.github.com'
-      - run: npm ci
-      - run: npm version patch
-      - run: git push --follow-tags
+      - name: Bump version (patch)
+        run: |
+          LATEST_TAG=$(git describe --tags --abbrev=0) || exit 1
+          NEW_COMMITS=$(git rev-list --count "${LATEST_TAG}"..) || exit 1
+          [ "${NEW_COMMITS}" -gt 0 ] || exit 0
+          git config user.name 'github-actions[bot]'
+          git config user.email '41898282+github-actions[bot]@users.noreply.github.com'
+          npm ci
+          npm version patch
+          git push --follow-tags
       # `npm publish` must come after `git push` otherwise there is a race
       # condition: If two PRs are merged back-to-back then master/main will be
       # updated with the commits from the second PR before the first PR's
@@ -79,5 +86,5 @@ jobs:
         env:
           NODE_AUTH_TOKEN: ${{secrets.NPM_TOKEN}}
 
-##ETHERPAD_NPM_V=2
-## NPM configuration automatically created using src/bin/plugins/updateAllPluginsScript.sh
+# Automatically generated by src/bin/plugins/checkPlugin.js
+##ETHERPAD_NPM_V=3