[New] nvm_resolve_alias: only resolve one line of a multiline alias file

Author: ljharb

nvm.sh

@@ -1177,8 +1177,10 @@ nvm_resolve_alias() {
 
   local SEEN_ALIASES
   SEEN_ALIASES="${ALIAS}"
+  local NVM_ALIAS_INDEX
+  NVM_ALIAS_INDEX=1
   while true; do
-    ALIAS_TEMP="$(nvm_alias "${ALIAS}" 2>/dev/null || nvm_echo)"
+    ALIAS_TEMP="$( (nvm_alias "${ALIAS}" 2>/dev/null | command head -n "${NVM_ALIAS_INDEX}" | command tail -n 1) || nvm_echo)"
 
     if [ -z "${ALIAS_TEMP}" ]; then
       break

test/fast/Aliases/nvm_resolve_alias

@@ -2,7 +2,9 @@
 
 die () { echo "$@" ; exit 1; }
 
-\. ../../../nvm.sh
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+\. "${NVM_DIR}/nvm.sh"
 
 EXIT_CODE=$(nvm_resolve_alias ; echo $?)
 [ $EXIT_CODE = "1" ] || die "nvm_resolve_alias without an argument did not return 1; got $EXIT_CODE"
@@ -31,3 +33,17 @@ UNSTABLE="$(nvm_resolve_alias unstable)"
 
 IOJS="$(nvm_resolve_alias iojs)"
 [ "_$IOJS" = "_iojs-v0.2" ] || die "'nvm_resolve_alias iojs' was not iojs-v0.2; got $IOJS"
+
+echo "
+
+v0.0.1
+v0.0.2
+v0.0.3
+" > ../../../alias/test-multi-lines
+
+EXPECTED='v0.0.1'
+ACTUAL="$(nvm_resolve_alias test-multi-lines)"
+EXIT_CODE="$(nvm_resolve_alias test-multi-lines 2>&1 >/dev/null; echo $?)"
+
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+[ "${EXIT_CODE}" = '0' ] || die "expected exit code 0, got ${EXIT_CODE}"

test/fast/Aliases/teardown

@@ -16,3 +16,4 @@ rm -f "../../../alias/node"
 rm -f "../../../alias/iojs"
 rm -f "../../../alias/default"
 rm -f "../../../alias/test-blank-lines"
+rm -f "../../../alias/test-multi-lines"