ci: add a script for vercel to determine if builds are necessary (#61713)

docs/check-docs-git-diff.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+set -eu
+
+# This script checks the status of the documentation files in the docs directory.
+# It should return '1' if a build is needed, and '0' if everything is up to date.
+#
+# This script will be called by Vercel here:
+# - https://vercel.com/airbyte-growth/airbyte-docs/settings/git#ignored-build-step
+#
+# This script is intended to be run from the root of the Airbyte repository.
+#
+# Usage:
+#   ./docs/check-docs-git-diff.sh                       # Check for any changes in the branch.
+#   ./docs/check-docs-git-diff.sh --latest-commit-only  # Only check the latest commit for changes.
+
+# parse flags
+LATEST_COMMIT_ONLY=false
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --latest-commit-only)
+      LATEST_COMMIT_ONLY=true
+      echo "⚙️ Running in '--latest-commit-only' mode."
+      echo "Only the most recent commit will be checked for changes."
+      ;;
+    *)
+      echo "Unknown argument: $1" >&2;
+      exit 1
+      ;;
+  esac
+  shift
+done
+
+latest_commit_message=$(git log -n 1 --oneline)
+echo "⚙️ Checking for a skip directive in the commit message: ('$latest_commit_message')"
+if echo "$latest_commit_message" | grep -Eq "\[(up-to-date|auto-publish)\]"; then
+    echo "✅ Skipping. Commit marked as [up-to-date]/[auto-publish]. ('$latest_commit_message')"
+    exit 0
+fi
+
+REMOTE=origin
+DEFAULT_BRANCH=master
+COMPARE_TO_REF="${REMOTE}/${DEFAULT_BRANCH}"
+if [ "$LATEST_COMMIT_ONLY" == 'true' ]; then
+    # We only want to compare the latest commit against the previous one:
+    COMPARE_TO_REF="HEAD^"
+fi
+
+echo "⚙️ Checking for git changes within the docs paths..."
+if git diff "${COMPARE_TO_REF}"...HEAD --quiet ./docusaurus ./docs .markdownlint.jsonc; then
+    echo "✅ No changes in docs paths. Skipping build."
+    exit 0
+fi
+
+# If we got here, then both of these conditions are true:
+# 1. There were changes in the docs or current directory, and
+# 2. The commit didn't have one of the tags [up-to-date] or [auto-publish].
+echo "❌ Documentation changes detected. Build is requested."
+exit 1