Partial bash completion for ng. This is a more functional version than the two liner in circulation.

ng-completion.sh

_ng() {
  local cur prev opts
  local NG_COMMANDS="add build config doc e2e generate help lint new run serve test update version xi18n"

  COMPREPLY=()
  cur="${COMP_WORDS[COMP_CWORD]}"
  prev="${COMP_WORDS[COMP_CWORD-1]}"
  opts="--help"
  posopts="${NG_COMMANDS}"

  if [[ ${cur} != -* && ${COMP_CWORD} -eq 1 ]] ; then
    COMPREPLY=( $(compgen -W "${posopts}" -- ${cur}) )
    return 0
  elif [[ ${cur} == -* ]] ; then
    COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
    return 0
  fi

  case "${prev}" in
    "generate"|"g")
      opts="--help -d -f --force --dry-run --defaults"
      posopts="class component module service"
      if [[ ${cur} != -* ]]; then
        COMPREPLY=($(compgen -W "${posopts}" -- ${cur}))
      else
        COMPREPLY=($(compgen -W "${opts}" -- ${cur}))
      fi
      ;;
    "help")
      opts="--help"
      if [[ ${cur} == -* ]]; then
        COMPREPLY=($(compgen -W "${opts}" -- ${cur}))
      fi
    ;;
  esac
}

command_exists () {
    command -v $1 >/dev/null 2>&1;
}

if  command_exists ng; then
  # No longer supported, please see https://github.com/angular/angular-cli/issues/11043
  # . <(ng completion --bash)
  complete -F _ng ng
fi

Google now seems to have resurrected the official in Angular support. Consider this file obsolete. Largely here as a reference for how this can be done in the absence of official support.