feat: Add emptyCommits option (#22)

* feat: Add emptyCommits option (@kingofzeal)
* docs: Update README about emptyCommits option (@kingofzeal)
* gha: Update trigger of docker image ci workflow (@peaceiris)

Close #21

.github/workflows/docker-image-ci.yml

@@ -1,10 +1,6 @@
 name: docker image ci
 
-on:
-  push:
-    branches:
-    - master
-    - 'release-v*'
+on: push
 
 jobs:
   test:
@@ -20,16 +16,6 @@ jobs:
         docker build . --file Dockerfile --tag ${DOCKER_IMAGE} ||
         (echo -e "\e[31m[${GITHUB_WORKFLOW}] failed to build\e[m" && exit 1)
 
-    # - name: push latest image
-    #   if: endsWith(github.ref, 'master')
-    #   env:
-    #     DOCKER_IMAGE: docker.pkg.github.com/${{ github.repository }}/action:latest
-    #     PKG_GITHUB_TOKEN: ${{ secrets.PKG_GITHUB_TOKEN }}
-    #   run: |
-    #     echo ${PKG_GITHUB_TOKEN} | docker login docker.pkg.github.com -u ${GITHUB_ACTOR} --password-stdin &&
-    #     docker push ${DOCKER_IMAGE} &&
-    #     docker logout
-
   shellcheck:
     runs-on: ubuntu-18.04
     steps:

README.md

@@ -27,6 +27,7 @@ Table of Contents
     - [:star: Pull action image from Docker Hub](#star-pull-action-image-from-docker-hub)
     - [:star: `PERSONAL_TOKEN`](#star-personal_token)
     - [:star: `GITHUB_TOKEN`](#star-github_token)
+    - [:star: Suppressing empty commits](#star-suppressing-empty-commits)
 - [Examples](#examples)
   - [Static Site Generators with Node.js](#static-site-generators-with-nodejs)
   - [Gatsby](#gatsby)
@@ -156,6 +157,25 @@ By pulling docker images, you can reduce the overall execution time of your work
 + GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 ```
 
+#### :star: Suppressing empty commits
+
+By default, a commit will always be generated and pushed to the `PUBLISH_BRANCH`, even if nothing changed. If you want to suppress this behavior, set the optional parameter `emptyCommits` to `false`. cf. [Issue #21]
+
+[Issue #21]: https://github.com/peaceiris/actions-gh-pages/issues/21
+
+For example:
+
+```yaml
+- name: deploy
+  uses: peaceiris/actions-gh-pages@v2.2.0
+  env:
+    ACTIONS_DEPLOY_KEY: ${{ secrets.ACTIONS_DEPLOY_KEY }}
+    PUBLISH_BRANCH: gh-pages
+    PUBLISH_DIR: ./public
+  with:
+    emptyCommits: false
+```
+
 
 
 ## Examples

action.yml

@@ -7,3 +7,8 @@ runs:
 branding:
   icon: 'upload-cloud'
   color: 'blue'
+inputs:
+  emptyCommits:
+    description: 'If empty commits should be made to the publication branch'
+    required: false
+    default: 'true'

entrypoint.sh

@@ -71,6 +71,16 @@ git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
 git remote rm origin || true
 git remote add origin "${remote_repo}"
 git add --all
-git commit --allow-empty -m "Automated deployment: $(date -u) ${GITHUB_SHA}"
+
+print_info "Allowing empty commits: ${INPUT_EMPTYCOMMITS}"
+COMMIT_MESSAGE="Automated deployment: $(date -u) ${GITHUB_SHA}"
+if [[ ${INPUT_EMPTYCOMMITS} == "true" ]]; then
+    git commit --allow-empty -m "${COMMIT_MESSAGE}"
+else
+    git commit -m "${COMMIT_MESSAGE}" || \
+      print_info "No changes detected, skipping deployment" && \
+      exit 0
+fi
+
 git push origin "${remote_branch}"
 print_info "${GITHUB_SHA} was successfully deployed"