From 7a339bdd3cf4da404a65fd89d554c08a746f790d Mon Sep 17 00:00:00 2001
From: Jordan Harband <ljharb@gmail.com>
Date: Wed, 22 Oct 2014 01:30:19 -0700
Subject: [PATCH] Adding nvm_resolve_alias

---
 nvm.sh                              | 35 +++++++++++++++++++++++------
 test/fast/Aliases/nvm_resolve_alias | 28 +++++++++++++++++++++++
 2 files changed, 56 insertions(+), 7 deletions(-)
 create mode 100755 test/fast/Aliases/nvm_resolve_alias

diff --git a/nvm.sh b/nvm.sh
index d712b4e..899b6da 100644
--- a/nvm.sh
+++ b/nvm.sh
@@ -270,6 +270,32 @@ nvm_ls_current() {
   fi
 }
 
+nvm_resolve_alias() {
+  if [ -z "$1" ]; then
+    return 1
+  fi
+
+  local PATTERN
+  PATTERN="$1"
+
+  if [ -f "$NVM_DIR/alias/$PATTERN" ]; then
+    nvm_version "$(nvm_alias "$PATTERN" 2> /dev/null)"
+    return 0
+  fi
+
+  if nvm_validate_implicit_alias "$PATTERN" 2> /dev/null ; then
+    local IMPLICIT
+    IMPLICIT="$(nvm_print_implicit_alias local "$PATTERN" 2> /dev/null)"
+    if [ -n "$IMPLICIT" ]; then
+      nvm_version "$IMPLICIT"
+      return $?
+    fi
+    return 3
+  fi
+
+  return 2
+}
+
 nvm_ls() {
   local PATTERN
   PATTERN=$1
@@ -280,10 +306,10 @@ nvm_ls() {
     return
   fi
 
-  if [ -f "$NVM_DIR/alias/$PATTERN" ]; then
-    nvm_version "$(nvm_alias "$PATTERN" 2> /dev/null)"
+  if nvm_resolve_alias "$PATTERN"; then
     return
   fi
+
   # If it looks like an explicit version, don't do anything funny
   PATTERN=$(nvm_ensure_version_prefix $PATTERN)
   if [ "_$(echo "$PATTERN" | cut -c1-1)" = "_v" ] && [ "_$(nvm_num_version_groups "$PATTERN")" = "_3" ]; then
@@ -292,11 +318,6 @@ nvm_ls() {
     fi
   else
     if [ "_$PATTERN" != "_system" ]; then
-      if nvm_validate_implicit_alias "$PATTERN" 2> /dev/null ; then
-        nvm_ls "$(nvm_print_implicit_alias local "$PATTERN" 2> /dev/null)"
-        return $?
-      fi
-
       local NUM_VERSION_GROUPS
       NUM_VERSION_GROUPS="$(nvm_num_version_groups "$PATTERN")"
       if [ "_$NUM_VERSION_GROUPS" = "_2" ] || [ "_$NUM_VERSION_GROUPS" = "_1" ]; then
diff --git a/test/fast/Aliases/nvm_resolve_alias b/test/fast/Aliases/nvm_resolve_alias
new file mode 100755
index 0000000..aaf4df2
--- /dev/null
+++ b/test/fast/Aliases/nvm_resolve_alias
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+EXIT_CODE=$(nvm_resolve_alias ; echo $?)
+[ $EXIT_CODE = "1" ] || die "nvm_resolve_alias without an argument did not return 1; got $EXIT_CODE"
+
+for i in $(seq 1 10)
+  do
+  STABLE_ALIAS="$(nvm_resolve_alias test-stable-$i)"
+  [ "_$STABLE_ALIAS" = "_v0.0.$i" ] \
+    || die "'nvm_resolve_alias test-stable-$i' was not v0.0.$i; got $STABLE_ALIAS"
+  UNSTABLE_ALIAS="$(nvm_resolve_alias test-unstable-$i)"
+  [ "_$UNSTABLE_ALIAS" = "_v0.1.$i" ] \
+    || die "'nvm_resolve_alias test-unstable-$i' was not v0.1.$i; got $UNSTABLE_ALIAS"
+done
+
+EXIT_CODE=$(nvm_resolve_alias nonexistent ; echo $?)
+[ $EXIT_CODE = "2" ] || die "'nvm_resolve_alias nonexistent' did not return 2; got $EXIT_CODE"
+
+STABLE="$(nvm_resolve_alias stable)"
+[ "_$STABLE" = "_v0.0.10" ] || die "'nvm_resolve_alias stable' was not v0.0.10; got $STABLE"
+
+UNSTABLE="$(nvm_resolve_alias unstable)"
+[ "_$UNSTABLE" = "_v0.1.10" ] || die "'nvm_resolve_alias unstable' was not v0.1.10; got $UNSTABLE"
+