nish.sh

nish.sh

# inspired by https://gist.github.com/assaf/ee377a186371e2e269a7
# requires [n](https://github.com/tj/n) and [jq](https://stedolan.github.io/jq/)

# Install nodejs version specified in package.json via n, otherwise use a blessed version
#
# Exit code:
# 0 Successfully installed and using the desired version
# 1 No package.json in current directory
#
# See debug messages by setting DEBUG=nish in your environment

function __nish_needs_resolution() {
  local semver=$1
  if ! [[ "$semver" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
    return 0
  else
    return 1
  fi
}

function __nish_install_nodejs() {
  local version="$1"

  if __nish_needs_resolution "$version"; then
    version=$(curl --silent --get --retry 5 --retry-max-time 15 --data-urlencode "range=${version}" https://semver.io/node/resolve)
  fi
  echo "Using node v$version"
  n $version
  return $?
}

function nish_debug () {
  if [[ "${DEBUG}" == "nish" ]] ; then
    echo "DEBUG: ${1}"
  fi
}


function nish() {
  if [[ ! -f package.json ]] ; then
    nish_debug "No package.json in current directory"
    return 0
  fi

  local blessed_nodejs_version=8
  local desired_nodejs_version=$(cat package.json | jq --raw-output .engines.node)
  [[ "$desired_nodejs_version" == "null" ]] && desired_nodejs_version="$blessed_nodejs_version"
  __nish_install_nodejs "$desired_nodejs_version" || return $?

  return 0
}

function cd() {
  builtin cd "$@"
  [ -z "$nish_NO_AUTO" ] && nish
}