error_masking_inside_if.sh

#!/usr/bin/env bash

set -o pipefail -o errtrace -o errexit -o nounset
shopt -s inherit_errexit

[[ -n "${TRACE:-}" ]] && set -o xtrace

trap 'stacktrace "Error trapped rc=${PIPESTATUS[@]}, see trace above"' ERR

stacktrace() {
  local frame="${#FUNCNAME[@]}"
  echo >&2 "Stacktrace:"
  while [[ "${frame}" -gt 1 ]]; do
    ((frame--))
    echo >&2 "  File ${BASH_SOURCE[$frame]}#L${BASH_LINENO[$((frame - 1))]} (in ${FUNCNAME[$frame]}())"
  done
  if [[ "$#" -gt 0 ]]; then
    echo >&2 "$1"
  fi
}

greetings() {
  echoo "TRUE"
}

good() {
  local res
  res="$(greetings)"
  if [[ "${res}" == "TRUE" ]]; then
    echo "Hello, world!"
  else
    echo "Goodbye, world!"
  fi
}

bad() {
  if [[ "$(greetings)" == "TRUE" ]]; then
    echo "Hello, world!"
  else
    echo "Goodbye, world!"
  fi
}

main() {
  bad
}

main "${@}"