Fix "unbound variable" error (#11)

Fix "unbound variable" error

bpkg.json

@@ -1,6 +1,6 @@
 {
   "name": "sh-validators",
-  "version": "v0.4.0",
+  "version": "v0.4.1",
   "description": "A set of scripts to validate user inputs",
   "scripts": [
     "fabasoad-validate-dir-exists",

lib/validate-dir-exists.sh

@@ -22,7 +22,7 @@ _fail() {
 fabasoad_validate_dir_exists() {
   if [ ! -d "${1}" ]; then
     msg=""
-    if [ -n "${2}" ]; then
+    if [ -n "${2:-""}" ]; then
       msg="${msg}\"${2}\" parameter is invalid. "
     fi
     printf "%s\"%s\" is not a directory or does not exist.\n" "${msg}" "${1}" >&2

lib/validate-enum.sh

@@ -27,7 +27,7 @@ fabasoad_validate_enum() {
       ;;
     *)
       msg=""
-      if [ -n "${3}" ]; then
+      if [ -n "${3:-""}" ]; then
         msg="${msg}\"${3}\" parameter is invalid. "
       fi
       printf "%s\"%s\" is invalid. Possible values: %s.\n" "${msg}" "${1}" "$(echo "${2}" | sed 's/,/, /g')" >&2

lib/validate-file-exists.sh

@@ -22,7 +22,7 @@ _fail() {
 fabasoad_validate_file_exists() {
   if [ ! -f "${1}" ]; then
     msg=""
-    if [ -n "${2}" ]; then
+    if [ -n "${2:-""}" ]; then
       msg="${msg}\"${2}\" parameter is invalid. "
     fi
     printf "%s\"%s\" is not a file or does not exist.\n" "${msg}" "${1}" >&2

lib/validate-semver.sh

@@ -33,7 +33,7 @@ fabasoad_validate_semver() {
 
   if ! [[ "${1}" =~ ^($D)\.($D)\.($D)(-(($D|$PW)(\.($D|$PW))*))?(\+($MW(\.$MW)*))?$ ]]; then
     msg=""
-    if [ -n "${2}" ]; then
+    if [ -n "${2:-""}" ]; then
       msg="${msg}\"${2}\" parameter is invalid. "
     fi
     printf "%s\"%s\" is not a valid semver.\n" "${msg}" "${1}" >&2

lib/validate-tool-installed.sh

@@ -22,7 +22,7 @@ _fail() {
 fabasoad_validate_tool_installed() {
   if ! command -v "${1}" &> /dev/null; then
     msg=""
-    if [ -n "${2}" ]; then
+    if [ -n "${2:-""}" ]; then
       msg="${msg}\"${2}\" parameter is invalid. "
     fi
     printf "%s\"%s\" is not installed on the current machine.\n" "${msg}" "${1}" >&2