parse-legacy-file

#!/usr/bin/env bash

set -Eeuo pipefail

[[ -n ${DEBUG-} ]] && set -x

# override is exposed for testing purposes.
THIS_PLUGIN="${ASDF_HASHICORP_THIS_PLUGIN:-"$(basename "$(dirname "$(dirname "$0")")")"}"
SUPPORTED_PLUGINS=(terraform packer)

is_strict_equality_version_constraint() {
  local -r version_constraint="$1"
  grep --quiet -E '^=?[[:digit:]]+\.[[:digit:]]+.[[:digit:]]+' <<<"${version_constraint}"
}

read_version_from_main_tf() {
  local -r version_file="$1"
  local -r required_version_constraint="$(grep --no-filename \
    --recursive \
    --fixed-strings \
    required_version \
    "${version_file}" |
    sed -E 's/[[:space:]]*required_version[[:space:]]*=//' |
    tr -d '" ')"

  [[ -z ${required_version_constraint} ]] && return 0

  if is_strict_equality_version_constraint "${required_version_constraint}"; then
    tr -d '=' <<<"${required_version_constraint}"
  else
    cat >&2 <<EOF
FATAL: Found legacy version file '${ASDF_HASHICORP_TERRAFORM_VERSION_FILE:-main.tf}' with unsupported required
version constraint expression: '${required_version_constraint}'. This
plugin only supports strict equality.

EOF
    exit 1
  fi
}

get_legacy_version() {
  local -r version_file="$1"
  local this_plugin_supported=false

  # check if current plugin is supported
  for plugin in "${SUPPORTED_PLUGINS[@]}"; do
    if [[ ${plugin} == "${THIS_PLUGIN}" ]]; then
      this_plugin_supported=true
      break
    fi
  done

  [[ ${this_plugin_supported} == false ]] && return 0

  if [[ ${version_file} == *".${THIS_PLUGIN}-version" && -r ${version_file} ]]; then
    cat "${version_file}"
  elif [[ ${version_file} =~ ${ASDF_HASHICORP_TERRAFORM_VERSION_FILE:-main.tf} && -r ${version_file} ]]; then
    read_version_from_main_tf "${version_file}"
  fi
}

get_legacy_version "$1"