From 27ef93013ccb9b9c51f69d3d1e0f06eb2e1a4c50 Mon Sep 17 00:00:00 2001
From: jordanbreen28 <jordan.breen@perforce.com>
Date: Wed, 1 May 2024 13:27:46 +0100
Subject: [PATCH] (CAT-1829) - Update to dynamic checkout ref gem_ci

This commit implements a dynamic checkout ref for the gem_ci workflow.
This is because we will be updating the calling workflows to be run on
the pull_request_target trigger so they can safely access secrets, so
this extra checkout logic is needed in order to checkout the head
branch.
---
 .github/workflows/gem_ci.yml | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/.github/workflows/gem_ci.yml b/.github/workflows/gem_ci.yml
index 2e2ed7b..fa3d64d 100644
--- a/.github/workflows/gem_ci.yml
+++ b/.github/workflows/gem_ci.yml
@@ -34,9 +34,22 @@ jobs:
       PUPPET_GEM_VERSION: ${{ inputs.puppet_gem_version }}
 
     steps:
+      # If we are on a PR, checkout the PR head sha, else checkout the default branch
+      # required when trigger set to pull_request_target
+      - name: "Set the checkout ref"
+        id: set_ref
+        run: |
+          if [[ "${{ github.event_name }}" == "pull_request_target" ]]; then
+            echo "ref=${{ github.event.pull_request.head.sha }}" >> $GITHUB_OUTPUT
+          else
+            echo "ref=${{ github.ref }}" >> $GITHUB_OUTPUT
+          fi
 
       - name: "checkout"
         uses: "actions/checkout@v4"
+        with:
+          fetch-depth: 1
+          ref: ${{ steps.set_ref.outputs.ref }}
 
       - name: "export environment"
         run: |