From 43f13f5fd1dc3d4c18101577ae3cf71a1da10e5a Mon Sep 17 00:00:00 2001
From: Michael Zalimeni <michael.zalimeni@hashicorp.com>
Date: Mon, 16 Sep 2024 17:27:26 -0400
Subject: [PATCH] ci: fix CI skip script hole

In some environments, the script will not fail despite SKIP_CHECK_BRANCH
being unset, leading to the script explicitly skipping CI when it should
fail fast.

Prevent this by explicitly checking for the env var.

This change is a port of https://github.com/hashicorp/consul/pull/21741.
---
 .github/scripts/check_skip_ci.sh | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/.github/scripts/check_skip_ci.sh b/.github/scripts/check_skip_ci.sh
index 0f65e46e..f7b70498 100755
--- a/.github/scripts/check_skip_ci.sh
+++ b/.github/scripts/check_skip_ci.sh
@@ -13,10 +13,11 @@ set -euo pipefail
 #
 # ... `git merge-base origin/$SKIP_CHECK_BRANCH HEAD` would return commit `D`
 # `...HEAD` specifies from the common ancestor to the latest commit on the current branch (HEAD)..
-files_to_check=$(git diff --name-only "$(git merge-base origin/$SKIP_CHECK_BRANCH HEAD~)"...HEAD)
+skip_check_branch=${SKIP_CHECK_BRANCH:?SKIP_CHECK_BRANCH is required}
+files_to_check=$(git diff --name-only "$(git merge-base origin/$skip_check_branch HEAD~)"...HEAD)
 
 # Define the directories to check
-skipped_directories=("_doc/" ".changelog/")
+skipped_directories=("_doc" ".changelog")
 
 # Loop through the changed files and find directories/files outside the skipped ones
 files_to_check_array=($files_to_check)
@@ -30,7 +31,7 @@ for file_to_check in "${files_to_check_array[@]}"; do
 	# - Markdown files
 	for dir in "${skipped_directories[@]}"; do
 		if [[ "$file_to_check" == */check_skip_ci.sh ]] ||
-		   [[ "$file_to_check" == "$dir"* ]] ||
+		   [[ "$file_to_check" == "$dir/"* ]] ||
 		   [[ "$file_to_check" == *.md ]]; then
 			file_is_skipped=true
 			break
@@ -46,4 +47,4 @@ for file_to_check in "${files_to_check_array[@]}"; do
 done
 
 echo "Changes detected in only documentation files - skipping tests and build"
-echo "skip-ci=true" >> "$GITHUB_OUTPUT"
\ No newline at end of file
+echo "skip-ci=true" >> "$GITHUB_OUTPUT"