Improve TestFlight message set by post build script in Xcode Cloud CI

ci_scripts/ci_post_xcodebuild.sh

@@ -11,7 +11,9 @@ set -eo pipefail
 if [[ -d "$CI_APP_STORE_SIGNED_APP_PATH" ]]; then
   TESTFLIGHT_DIR_PATH=../TestFlight
   mkdir -p $TESTFLIGHT_DIR_PATH
-  cat <<EOF > "$TESTFLIGHT_DIR_PATH/WhatToTest.en-US.txt"
+  TESTFLIGHT_FILE_PATH=$TESTFLIGHT_DIR_PATH/WhatToTest.en-US.txt
+
+  cat <<EOF > "$TESTFLIGHT_FILE_PATH"
 (To unsubscribe from TestFlight emails, open the TestFlight app, tap on Zotero, and disable Email Notifications. We’re not able to unsubscribe you from TestFlight emails on our end.)
 
 You’re using the beta version of Zotero for iOS. You can reinstall the production version of the app from the App Store at any time.
@@ -24,11 +26,14 @@ Please post to the Zotero Forums with all bug reports and feature requests.
 
 Thanks for helping to test Zotero for iOS.
 
-branch: ${CI_BRANCH:-$(git symbolic-ref --short HEAD)}
-commit: $(git log -n 1 --pretty=format:"%h")
-message: $(git log -n 1 --pretty=format:"%s")
 EOF
 
+  if [[ -n "$CI_BRANCH" ]]; then
+    echo "branch: $CI_BRANCH" >> "$TESTFLIGHT_FILE_PATH"
+  fi
+  echo "commit: $(git log -n 1 --pretty=format:"%h")" >> "$TESTFLIGHT_FILE_PATH"
+  echo "message: $(git log -n 1 --pretty=format:"%s")" >> "$TESTFLIGHT_FILE_PATH"
+
   # Push version-build tag to origin
   VERSION=$(cat ../${CI_PRODUCT}.xcodeproj/project.pbxproj | grep -m1 'MARKETING_VERSION' | cut -d'=' -f2 | tr -d ';' | tr -d ' ')
   TAG="${VERSION}-${CI_BUILD_NUMBER}"