feat: Add INPUT_FORCEORPHAN (#43)

* feat: Add INPUT_FORCEORPHAN option (close #42)
* docs: Add new section about Force orphan

Author: peaceiris

README.md

@@ -294,6 +294,22 @@ When you use `ACTIONS_DEPLOY_KEY`, set your private key to the repository which
 
 Be careful, `GITHUB_TOKEN` has no permission to access to external repositories.
 
+### ⭐️ Force orphan
+
+From `v2.6.0`, we can set the `forceOrphan: true` option.
+This allows you to make your publish branch with only the latest commit.
+
+```yaml
+- name: Deploy
+  uses: peaceiris/[email protected]
+  env:
+    ACTIONS_DEPLOY_KEY: ${{ secrets.ACTIONS_DEPLOY_KEY }}
+    PUBLISH_BRANCH: gh-pages
+    PUBLISH_DIR: ./public
+  with:
+    forceOrphan: true
+```
+
 ### ⭐️ Script mode
 
 From `v2.5.0`, we can run this action as a shell script.

action.yml

@@ -16,3 +16,7 @@ inputs:
     description: 'If existing files in the publish branch should be not removed before deploying'
     required: false
     default: 'false'
+  forceOrphan:
+    description: 'Keep only the latest commit on a GitHub Pages branch'
+    required: false
+    default: 'false'

entrypoint.sh

@@ -77,7 +77,13 @@ fi
 remote_branch="${PUBLISH_BRANCH}"
 
 local_dir="${HOME}/ghpages_${RANDOM}"
-if git clone --depth=1 --single-branch --branch "${remote_branch}" "${remote_repo}" "${local_dir}"; then
+
+if [[ "${INPUT_FORCEORPHAN}" == "true" ]]; then
+    print_info "force ophan: ${INPUT_FORCEORPHAN}"
+    cd "${PUBLISH_DIR}"
+    git init
+    git checkout --orphan "${remote_branch}"
+elif git clone --depth=1 --single-branch --branch "${remote_branch}" "${remote_repo}" "${local_dir}"; then
     cd "${local_dir}"
 
     if [[ ${INPUT_KEEPFILES} == "true" ]]; then
@@ -110,5 +116,10 @@ else
     git commit --allow-empty -m "${COMMIT_MESSAGE}"
 fi
 
-git push origin "${remote_branch}"
+if [[ ${INPUT_FORCEORPHAN} == "true" ]]; then
+    git push origin --force "${remote_branch}"
+else
+    git push origin "${remote_branch}"
+fi
+
 print_info "${GITHUB_SHA} was successfully deployed"