How to exit bash function if error?

1. Use subshell ( .. ) with set -e; to make it more concise, you can do this:

build() {( set -e        # Fail early
  build_cmd_step_1
  build_cmd_step_2
  build_cmd_step_3
  ...
)}

Then, the function will fail on the first failure and you can intercept the exit status:

build
exit_status=$?
if [ ${exit_status} -ne 0 ]; then
  echo "We have error - build failed!"
  exit "${exit_status}"
fi

2. Alternatively, the && \ chaining inside a function is also good (https://stackoverflow.com/a/51913013/1375784), though it might get bad if you have a bigger function.

Both methods can be good, depending on your use case (in some cases using subshells may cause some unwanted side effects)