Fix all Shellcheck SC2236 violations.

bpkg.sh

@@ -90,7 +90,7 @@ bpkg () {
         {
           declare -a local res=($(commands))
 
-          if [ ! -z "${res}" ]; then
+          if [ -n "${res}" ]; then
             echo
             echo  >&2 "Did you mean one of these?"
             found=0

lib/init/init.sh

@@ -22,7 +22,7 @@ prompt () {
 
     value="${value//\"/\'}";
   } 2>&1
-  if [ ! -z "${value}" ]; then
+  if [ -n "${value}" ]; then
     eval "${var}=\"${value}\""
   fi
 }
@@ -128,7 +128,7 @@ required () {
 
 ## convert scripts to quoted csv
 csv () {
-  if [ ! -z "${SCRIPTS}" ]; then
+  if [ -n "${SCRIPTS}" ]; then
     RAW_SCRIPTS=${SCRIPTS}
     {
       local TMP=""
@@ -166,7 +166,7 @@ delimit () {
     local lowercase="$(echo ${key} | tr '[:upper:]' '[:lower:]')"
 
     eval local val="\${${key}}"
-    if [ ! -z "${val}" ]; then
+    if [ -n "${val}" ]; then
 
       ## swap leading/trailing quotes for brackets in arrays
       local before="\""
@@ -293,7 +293,7 @@ bpkg_init () {
       ;;
 
     *)
-      if [ ! -z "${arg}" ]; then
+      if [ -n "${arg}" ]; then
         error "Unknown option: \`${arg}'"
         usage
         exit 1

lib/install/install.sh

@@ -404,7 +404,7 @@ bpkg_install_from_remote () {
 
     { (
       ## go to tmp dir
-      cd "$( [[ ! -z "${TMPDIR}" ]] && echo "${TMPDIR}" || echo /tmp)" &&
+      cd "$( [[ -n "${TMPDIR}" ]] && echo "${TMPDIR}" || echo /tmp)" &&
         ## prune existing
       rm -rf "${name}-${version}" &&
         ## shallow clone

lib/term/term.sh

@@ -269,7 +269,7 @@ term () {
         "${cmd}" "${@}"
         return $?
       else
-        if [ ! -z "${arg}" ]; then
+        if [ -n "${arg}" ]; then
           error "Unknown argument: \`${arg}'"
         fi
         usage