fix: Refuse to push on pull_request event

Avoid merging pull requests, which is unlikely to be the intended
purpose of using this action.

Author: Kurt-von-Laven

README.md

@@ -76,6 +76,8 @@ jobs:
 | `git_name`                     | Name used to configure git (for git operations)                                                                                                                                                                                   | `github-actions[bot]`                                           |
 | `git_email`                    | Email address used to configure git (for git operations)                                                                                                                                                                          | `github-actions[bot]@users.noreply.github.com`                  |
 | `push`                         | Define if the changes should be pushed to the branch.                                                                                                                                                                             | true                                                            |
+| `merge`                        | Define if the changes should be pushed even on the pull_request event, immediately merging the pull request.                                                                                                                      | false                                                           |
+
 | `commit`                       | Define if the changes should be committed to the branch.                                                                                                                                                                          | true                                                            |
 | `commitizen_version`           | Specify the version to be used by commitizen. Eg: `2.21.0`                                                                                                                                                                        | latest                                                          |
 | `changelog`                    | Create changelog when bumping the version                                                                                                                                                                                         | true                                                            |

action.yml

@@ -21,6 +21,12 @@ inputs:
     description: 'If true the bump commit is pushed to the remote repository'
     required: false
     default: "true"
+  merge:
+    description: >
+      If true, the bump commit is pushed to the remote repository even when the
+      action is run on the pull_request event, immediately merging the pull request
+    required: false
+    default: "false"
   prerelease:
     description: 'Set as prerelease version'
     required: false

entrypoint.sh

@@ -72,10 +72,15 @@ echo "Repository: ${INPUT_REPOSITORY}"
 echo "Actor: ${GITHUB_ACTOR}"
 
 if [[ $INPUT_PUSH == 'true' ]]; then
-  echo "Pushing to branch..."
-  REMOTE_REPO="https://${GITHUB_ACTOR}:${INPUT_GITHUB_TOKEN}@github.com/${INPUT_REPOSITORY}.git"
-  git pull "$REMOTE_REPO" "$INPUT_BRANCH"
-  git push "$REMOTE_REPO" "HEAD:${INPUT_BRANCH}" --tags
+  if [[ $INPUT_MERGE != 'true' && $GITHUB_EVENT_NAME == 'pull_request' ]]; then
+    echo "Refusing to push on pull_request event since that would merge the pull request." >&2
+    echo "You probably want to run on push to your default branch instead." >&2
+  else
+    echo "Pushing to branch..."
+    REMOTE_REPO="https://${GITHUB_ACTOR}:${INPUT_GITHUB_TOKEN}@github.com/${INPUT_REPOSITORY}.git"
+    git pull "$REMOTE_REPO" "$INPUT_BRANCH"
+    git push "$REMOTE_REPO" "HEAD:${INPUT_BRANCH}" --tags
+  fi
 else
   echo "Not pushing"
 fi