invim

#!/usr/bin/env bash
set -o errexit

if [[ ! $NVIM_LISTEN_ADDRESS ]] ; then
  echo 'Error: Neovim must be running and have set $NVIM_LISTEN_ADDRESS for invim to communicate with it' >&2
  exit 1
fi

# Now that we've checked for NVIM_LISTEN_ADDRESS, we don't want any more undefined
set -o nounset

# Defaults
OPEN_METHOD=edit
# We're assigning this to our Lua wait variable, so use Lua boolean literals
WAIT="false"
# Unless we're doing a dryrun, run an nvim that starts up as quickly as possible to run the Lua we
# give it
COMMAND='nvim --headless -u NONE -i NONE -n -s -'

# From https://stackoverflow.com/a/23002317. Removed -f check to allow for files that don't yet exist
function abspath() {
  if [ -d "$1" ]; then # dir
    (cd "$1"; pwd)
  elif [[ $1 = /* ]]; then
    echo "$1"
  elif [[ $1 == */* ]]; then
    echo "$(cd "${1%/*}"; pwd)/${1##*/}"
  else
    echo "$(pwd)/$1"
  fi
}

function usage() {
  cat <<'EOF'
Usage:
  invim [options] file  Edit file in the Neovim running at $NVIM_LISTEN_ADDRESS

Options:
  --remote            Open the file with :edit. This is the default
  -w, --remote-wait   Wait for the file's buffer to be deleted before exiting
  -o, --split         Open the file with :split
  -O, --vsplit        Open the file with :vsplit
  -p, --tabedit       Open the file with :tabedit
  -l, --last          Move to the previous window and open the file with :edit
  -n, --dry-run       Print what Neovim would execute instead of executing it
EOF
exit $1
}

TO_EDIT=""
# From https://medium.com/@Drew_Stokes/bash-argument-parsing-54f3b81a6a8f
while (( "$#" )); do
  case "$1" in
    --remote)
      WAIT="false"
      shift
      ;;
    -w|--remote-wait)
      WAIT="true"
      shift
      ;;
    -o|--split)
      OPEN_METHOD=split
      shift
      ;;
    -O|--vsplit)
      OPEN_METHOD=vsplit
      shift
      ;;
    -p|--tabedit)
      OPEN_METHOD=tabedit
      shift
      ;;
    -l|--last)
      OPEN_METHOD="wincmd p | edit"
      shift
      ;;
    -n|--dry-run)
      COMMAND=cat
      shift
      ;;
    -h|--help)
      usage 0
      ;;
    -*|--*=) # unsupported flags
      echo "Error: Unsupported flag $1" >&2
      echo
      usage 1
      ;;
    *) # an unbound argument is the file to edit
      if [[ $TO_EDIT ]] ; then
        echo "Error: May only pass in a single file to edit. '$1' is extra" >&2
        exit 1
      fi
      TO_EDIT="[===[$(abspath $1)]===]"
      shift
      ;;
  esac
done

if [[ ! $TO_EDIT ]] ; then
  echo "Error: Must pass in a file to edit" >&2
  echo
  usage 1
fi

# Neovim refuses to not print the initial command it gets with -s, at least as far as I can tell.
# To keep from having that output when the command works, grep it out using the technique from
# https://stackoverflow.com/a/15936384. Using the subcommand allows nvim's exit code to pass
# through
# Putting it together: start with our nvim command, redirect its stderr to grep out its distracting
# output, and feed in the Lua for nvim to execute via the EOF heredoc
$COMMAND \
  2> >(grep -v ":silent lua <<EOLUA" 1>&2) \
  <<EOF
:silent lua <<EOLUA
local wait = $WAIT
local addr = vim.fn.getenv("NVIM_LISTEN_ADDRESS")
local chanId = vim.fn.sockconnect('pipe', addr, { rpc = true })
local script = '$OPEN_METHOD ' .. $TO_EDIT
if wait then
  local remoteChanId = vim.fn.rpcrequest(chanId, 'nvim_get_api_info')[1]
  script = string.format([[
%s
  set bufhidden=delete
  augroup neditor
    autocmd BufDelete <buffer> silent! call rpcnotify(%d, 'nvim_command', 'quit')
   augroup END
]], script, remoteChanId)
end
vim.fn.rpcrequest(chanId, 'nvim_exec', script, false)
if not wait then
   vim.api.nvim_command('quit')
 end
EOLUA
EOF