`nvm run`: add `--lts`/`--lts=argon` support

nvm.sh

@@ -1847,6 +1847,8 @@ nvm() {
       nvm_echo '    --lts                                   Uses automatic LTS (long-term support) alias `lts/*`, if available.'
       nvm_echo '    --lts=<LTS name>                        Uses automatic alias for provided LTS line, if available.'
       nvm_echo '  nvm run [--silent] <version> [<args>]     Run `node` on <version> with <args> as arguments. Uses .nvmrc if available'
+      nvm_echo '    --lts                                   Uses automatic LTS (long-term support) alias `lts/*`, if available.'
+      nvm_echo '    --lts=<LTS name>                        Uses automatic alias for provided LTS line, if available.'
       nvm_echo '  nvm current                               Display currently activated version'
       nvm_echo '  nvm ls                                    List installed versions'
       nvm_echo '  nvm ls <version>                          List versions matching a given <version>'
@@ -2332,10 +2334,13 @@ nvm() {
       shift
 
       local NVM_SILENT
+      local NVM_LTS
       while [ $# -gt 0 ]
       do
         case "$1" in
           --silent) NVM_SILENT='--silent' ; shift ;;
+          --lts) NVM_LTS='*' ; shift ;;
+          --lts=*) NVM_LTS="${1##--lts=}" ; shift ;;
           *)
             if [ -n "$1" ]; then
               break
@@ -2346,7 +2351,7 @@ nvm() {
         esac
       done
 
-      if [ $# -lt 1 ]; then
+      if [ $# -lt 1 ] && [ -z "${NVM_LTS-}" ]; then
         if [ -n "${NVM_SILENT-}" ]; then
           nvm_rc_version >/dev/null 2>&1 && has_checked_nvmrc=1
         else
@@ -2354,30 +2359,30 @@ nvm() {
         fi
         if [ -n "$NVM_RC_VERSION" ]; then
           VERSION="$(nvm_version "$NVM_RC_VERSION" || return 0)"
-        else
-          VERSION='N/A'
         fi
-        if [ $VERSION = "N/A" ]; then
+        if [ "${VERSION:-N/A}" = 'N/A' ]; then
           >&2 nvm --help
           return 127
         fi
       fi
 
-      provided_version="$1"
-      if [ -n "$provided_version" ]; then
-        VERSION="$(nvm_version "$provided_version" || return 0)"
-        if [ "_$VERSION" = "_N/A" ] && ! nvm_is_valid_version "$provided_version"; then
-          provided_version=''
-          if [ $has_checked_nvmrc -ne 1 ]; then
+      if [ -z "${NVM_LTS-}" ]; then
+        provided_version="$1"
+        if [ -n "$provided_version" ]; then
+          VERSION="$(nvm_version "$provided_version" || return 0)"
+          if [ "_${VERSION:-N/A}" = '_N/A' ] && ! nvm_is_valid_version "$provided_version"; then
+            provided_version=''
+            if [ $has_checked_nvmrc -ne 1 ]; then
             if [ -n "${NVM_SILENT-}" ]; then
-              nvm_rc_version >/dev/null 2>&1 && has_checked_nvmrc=1
-            else
-              nvm_rc_version && has_checked_nvmrc=1
+                nvm_rc_version >/dev/null 2>&1 && has_checked_nvmrc=1
+              else
+                nvm_rc_version && has_checked_nvmrc=1
+              fi
             fi
+            VERSION="$(nvm_version "$NVM_RC_VERSION" || return 0)"
+          else
+            shift
           fi
-          VERSION="$(nvm_version "$NVM_RC_VERSION" || return 0)"
-        else
-          shift
         fi
       fi
 
@@ -2394,12 +2399,17 @@ nvm() {
         ZSH_HAS_SHWORDSPLIT_UNSET="$(setopt | nvm_grep shwordsplit > /dev/null && nvm_echo $? || nvm_echo $?)"
         setopt shwordsplit
       fi
+      local LTS_ARG
+      if [ -n "${NVM_LTS-}" ]; then
+        LTS_ARG="--lts=${NVM_LTS-}"
+        VERSION=''
+      fi
       if [ "_$VERSION" = "_N/A" ]; then
         nvm_ensure_version_installed "$provided_version"
       elif [ "$NVM_IOJS" = true ]; then
-        nvm exec "${NVM_SILENT-}" "$VERSION" iojs "$@"
+        nvm exec "${NVM_SILENT-}" "${LTS_ARG-}" "$VERSION" iojs "$@"
       else
-        nvm exec "${NVM_SILENT-}" "$VERSION" node "$@"
+        nvm exec "${NVM_SILENT-}" "${LTS_ARG-}" "$VERSION" node "$@"
       fi
       EXIT_CODE="$?"
       if [ "$ZSH_HAS_SHWORDSPLIT_UNSET" -eq 1 ] && nvm_has "unsetopt"; then