Bash autocompletion for nx

nx.completion.bash

#!/usr/bin/env bash

# Very naive completion for nx <https://www.npmjs.com/package/nx>.
#
# - Requires jq(1) to be present for completion of targets.
# - Uses _get_comp_words_by_ref and __ltrim_colon_completions which are
#   usully found in /etc/bash_completion
#
# Gist: https://gist.github.com/marek-saji/dee1df3cd7af3f6b74e608ab1d7ec473
#
# Licensed under ISC license:
#
# Copyright © 2023 Marek “saji” Augustynowicz <marek.aug@gmail.com>
#
# Permission to use, copy, modify, and/or distribute this software for
# any purpose with or without fee is hereby granted, provided that the
# above copyright notice and this permission notice appear in all
# copies.
#
# THE SOFTWARE IS PROVIDED “AS IS” AND ISC DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY
# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

_nx_complete_command ()
{
  local cur="$1"

  # shellcheck disable=SC2207
  COMPREPLY=($(
    compgen \
      -W "$( nx 2>&1 --help | grep -o '^  nx [a-z:-]*' | cut -d' ' -f4 )" \
      -- "$cur"
    ))
}

_nx_complete_projects ()
{
  local cur="$1"

  # shellcheck disable=SC2207
  COMPREPLY=($(
    compgen \
      -W "$( nx show projects )" \
      -- "$cur"
  ))
}

_nx_complete_command_show ()
{
  local cur="$1"

  # shellcheck disable=SC2207
  COMPREPLY=($(
    compgen \
      -W "project projects" \
      -- "$cur"
  ))
}

_nx_complete_command_run ()
{
  local cur="$1"

  if command -v jq >/dev/null 2>&1
  then
    # shellcheck disable=SC2207
    COMPREPLY=($(
      compgen \
        -W "$( jq 2>/dev/null -r '.name, .name + ":" + (.targets | keys | .[])' ./**/project.json | sort -u )" \
        -- "$cur"
    ))
  fi
}

_nx_complete_target ()
{
  local cur="$1"

  if command -v jq >/dev/null 2>&1
  then
    # shellcheck disable=SC2207
    COMPREPLY=($(
      # More correct way, but slow:
      # nx show projects | xargs -n1 nx show project | jq -r '.targets | keys | .[]' | sort -u
      compgen \
        -W "$( jq 2>/dev/null -r '.targets | keys | .[]' ./**/project.json | sort -u )" \
        -- "$cur"
    ))
  fi
}

_nx_complete_branch ()
{
  local cur="$1"

  # shellcheck disable=SC2207
  COMPREPLY=($(
    compgen \
      -W "$( git branch --all --format='%(refname:short)' )" \
      -- "$cur"
  ))
}

_nx_complete_arg ()
{
  local cur="$1"
  local prev="$2"
  local command="$3"

  if [ "${cur:0:1}" = '-' ]
  then
    # shellcheck disable=SC2207
    COMPREPLY=($(
      compgen \
        -W "$( nx 2>&1 "$command" --help | grep -Eo '^\s*(-[a-z-]*,?\s*)*' | grep -oE -- '-[a-z-]*' | sort -u )" \
        -- "$cur"
    ))
  else
    local prev_word="${COMP_WORDS[COMP_CWORD - 1]}"
    case "$prev_word" in
      '-t' | '--target' | '--with-target')
        _nx_complete_target "$cur"
        ;;
      '--base' | '--head' )
        _nx_complete_branch "$cur"
        ;;
    esac
  fi
}

_nx_complete ()
{
  local words cword prev cur
  _get_comp_words_by_ref -n : words cword prev cur

  # DEBUG
  # printf "\n<debug>\n"
  # # set | grep ^COMP_
  # echo "  words=( ${words[*]} )"
  # echo "  cur=$cur"
  # echo "  prev=$prev"
  # echo "  cword=$cword"
  # printf "</debug>\n"

  if [ "$cword" -eq 1 ]
  then
    # TODO Also autocomplete `nx TARGET PROJECT RUN_ARGS`
    _nx_complete_command "$cur"
  elif [ "${words[*]:1:1}" = "show" ] && [ "$cword" -eq 2 ]
  then
    _nx_complete_command_show "$cur"
  elif [ "${words[*]:1:2}" = "show project" ] && [ "$cword" -eq 3 ]
  then
    _nx_complete_projects "$cur"
  elif [ "${words[*]:1:1}" = "run" ] && [ "$cword" -eq 2 ]
  then
    _nx_complete_command_run "$cur"
  else
    command="${words[1]}"
    _nx_complete_arg "$cur" "$prev" "$command"
  fi

  __ltrim_colon_completions "$cur"
}

complete -F _nx_complete nx