Fix "Branch 'main' does not exist" error (#24)

* add dependabot file

* validate the action yml file too

* add GITHUB_BASE_REF

* improve default branch detection in GitHub Actions

The `git remote show origin` command can be unreliable for determining the default branch in some CI environments, particularly for pull requests from forks.

This change updates the validation script to prioritize the `GITHUB_BASE_REF` environment variable when it is available. This provides a more robust method for identifying the target branch within a GitHub Actions workflow.

Additionally, the script is modified to skip the branch checkout logic when running in a PR context, as the correct branch is already checked out by the workflow.

* update trigger events to include push for plugin version validation

Author: jazzsequence

.github/workflows/test.yml

@@ -1,5 +1,5 @@
 name: Validate Plugin Version Test
-on: [pull_request]
+on: [push, pull_request]
 jobs:
   test:
     runs-on: ubuntu-latest

action.yml

@@ -24,7 +24,6 @@ inputs:
   branch:
     description: The branch to use as the base for PRs and commit the changes back to.
     required: false
-    default: 'main'
   pr-status:
     description: The status of the PR to create. Default is 'draft'. Accepts 'draft' or 'open'.
     required: false
@@ -50,5 +49,6 @@ runs:
         FILENAMES: ${{ inputs.filenames }}
         BRANCH: ${{ inputs.branch }}
         PR_STATUS: ${{ inputs.pr-status }}
+        GITHUB_BASE_REF: ${{ github.base_ref }}
       run: bash ${{ github.action_path }}/bin/validate-plugin-version.sh
 

bin/validate-plugin-version.sh

@@ -3,12 +3,15 @@ set -euo pipefail
 IFS=$'\n\t'
 
 main() {
-	# Determine the default branch
-	DEFAULT_BRANCH=$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)
+	if [[ -n "${GITHUB_BASE_REF:-}" ]]; then
+		DEFAULT_BRANCH="${GITHUB_BASE_REF}"
+	else
+		DEFAULT_BRANCH=$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)
+	fi
 	echo "Default branch is $DEFAULT_BRANCH"
 
 	# Check out the specified branch if $BRANCH is set and not already on it
-	if [[ -n "${BRANCH:-}" && "$(git rev-parse --abbrev-ref HEAD)" != "$BRANCH" ]]; then
+	if [[ -z "${GITHUB_BASE_REF:-}" && -n "${BRANCH:-}" && "$(git rev-parse --abbrev-ref HEAD)" != "$BRANCH" ]]; then
 		echo "Checking if branch $BRANCH exists."
 		if ! git show-ref --verify --quiet "refs/heads/$BRANCH"; then
 			if git show-ref --verify --quiet "refs/remotes/origin/$BRANCH"; then