Run coverage when test-coverage.sh is modified

ci/pr-snap.sh

@@ -4,16 +4,11 @@ set -e
 # Only run snap.sh for pull requests that modify files under /snap
 #
 
-cd "$(dirname "$0")"
+cd "$(dirname "$0")"/..
 
-if ./is-pr.sh; then
-  affected_files="$(buildkite-agent meta-data get affected_files)"
-  echo "Affected files in this PR: $affected_files"
-  if [[ ! ":$affected_files:" =~ :snap/ ]]; then
-    echo "Skipping snap build as no files under /snap were modified"
-    exit 0
-  fi
-  exec ./snap.sh
-else
-  echo "Skipping snap build as this is not a pull request"
-fi
+ci/affects-files.sh :snap/ || {
+  echo "Skipping snap build as no files under /snap were modified"
+  exit 0
+}
+
+exec ci/snap.sh