From aface01a4d23e0b6a00cb5d15d9c04d3ff75776c Mon Sep 17 00:00:00 2001
From: Jake Lodwick <25925+jakelodwick@users.noreply.github.com>
Date: Tue, 17 Feb 2026 13:44:31 -0700
Subject: [PATCH 1/3] [Refactor] `nvm_alias`, `nvm_resolve_alias`: use builtins

[Tests] `nvm_alias`, `nvm_resolve_alias`: add edge-case tests

nvm_alias() used a sed/awk pipeline to strip comments and blank lines from alias files that almost always contain a single word.
A while-read loop with parameter expansion does the same filtering more directly.

nvm_resolve_alias() piped nvm_alias through head and tail to extract one line, and used printf/grep for cycle detection.
Parameter expansion and a case statement replace both without the extra plumbing.

All replacements are POSIX (read -r, case, IFS=, parameter expansion).
As a side effect, this also removes 4 external process invocations during shell init.
---
 nvm.sh                                        | 28 +++++++++++++++----
 .../nvm_alias handles comment-only alias file | 17 +++++++++++
 .../nvm_alias handles empty alias file        | 17 +++++++++++
 .../nvm_alias strips trailing whitespace      | 16 +++++++++++
 .../nvm_resolve_alias handles deep chain      | 20 +++++++++++++
 .../nvm_resolve_alias with nonexistent target | 19 +++++++++++++
 6 files changed, 111 insertions(+), 6 deletions(-)
 create mode 100755 test/fast/Aliases/nvm_alias handles comment-only alias file
 create mode 100755 test/fast/Aliases/nvm_alias handles empty alias file
 create mode 100755 test/fast/Aliases/nvm_alias strips trailing whitespace
 create mode 100755 test/fast/Aliases/nvm_resolve_alias handles deep chain
 create mode 100755 test/fast/Aliases/nvm_resolve_alias with nonexistent target

diff --git a/nvm.sh b/nvm.sh
index 7268de2570..98ef38719a 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -1323,7 +1323,22 @@ nvm_alias() {
     return 2
   fi
 
-  command sed 's/#.*//; s/[[:space:]]*$//' "${NVM_ALIAS_PATH}" | command awk 'NF'
+  local NVM_ALIAS_LINE
+  while IFS= read -r NVM_ALIAS_LINE || [ -n "${NVM_ALIAS_LINE}" ]; do
+    NVM_ALIAS_LINE="${NVM_ALIAS_LINE%%#*}"
+    case "${NVM_ALIAS_LINE}" in
+      *[!\ \	]*) ;;
+      *) continue ;;
+    esac
+    while : ; do
+      case "${NVM_ALIAS_LINE}" in
+        *' ') NVM_ALIAS_LINE="${NVM_ALIAS_LINE% }" ;;
+        *'	') NVM_ALIAS_LINE="${NVM_ALIAS_LINE%	}" ;;
+        *) break ;;
+      esac
+    done
+    nvm_echo "${NVM_ALIAS_LINE}"
+  done < "${NVM_ALIAS_PATH}"
 }
 
 nvm_ls_current() {
@@ -1356,13 +1371,14 @@ nvm_resolve_alias() {
   local ALIAS
   ALIAS="${PATTERN}"
   local ALIAS_TEMP
+  local ALIAS_OUTPUT
 
   local SEEN_ALIASES
-  SEEN_ALIASES="${ALIAS}"
-  local NVM_ALIAS_INDEX
-  NVM_ALIAS_INDEX=1
+  SEEN_ALIASES=" ${ALIAS} "
   while true; do
-    ALIAS_TEMP="$( (nvm_alias "${ALIAS}" 2>/dev/null | command head -n "${NVM_ALIAS_INDEX}" | command tail -n 1) || nvm_echo)"
+    ALIAS_OUTPUT="$(nvm_alias "${ALIAS}" 2>/dev/null)" || ALIAS_OUTPUT=''
+    ALIAS_TEMP="${ALIAS_OUTPUT%%
+*}"
 
     if [ -z "${ALIAS_TEMP}" ]; then
       break
@@ -1373,7 +1389,7 @@ nvm_resolve_alias() {
       break
     fi
 
-    SEEN_ALIASES="${SEEN_ALIASES}\\n${ALIAS_TEMP}"
+    SEEN_ALIASES="${SEEN_ALIASES}${ALIAS_TEMP} "
     ALIAS="${ALIAS_TEMP}"
   done
 
diff --git a/test/fast/Aliases/nvm_alias handles comment-only alias file b/test/fast/Aliases/nvm_alias handles comment-only alias file
new file mode 100755
index 0000000000..cb8fa077ff
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles comment-only alias file	
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file containing only comments
+printf '# this is a comment\n# another comment\n' > ../../../alias/test-edge-comments
+ACTUAL="$(nvm_alias test-edge-comments 2>/dev/null)"
+EXIT_CODE="$(nvm_alias test-edge-comments 2>/dev/null; echo $?)"
+[ -z "${ACTUAL}" ] || die "expected empty output for comment-only alias file, got >${ACTUAL}<"
+[ "${EXIT_CODE}" = '0' ] || die "expected exit code 0, got ${EXIT_CODE}"
+
+rm -f ../../../alias/test-edge-comments
diff --git a/test/fast/Aliases/nvm_alias handles empty alias file b/test/fast/Aliases/nvm_alias handles empty alias file
new file mode 100755
index 0000000000..3f80c73ad4
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles empty alias file	
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an empty alias file
+printf '' > ../../../alias/test-edge-empty
+ACTUAL="$(nvm_alias test-edge-empty 2>/dev/null)"
+EXIT_CODE="$(nvm_alias test-edge-empty 2>/dev/null; echo $?)"
+[ -z "${ACTUAL}" ] || die "expected empty output for empty alias file, got >${ACTUAL}<"
+[ "${EXIT_CODE}" = '0' ] || die "expected exit code 0, got ${EXIT_CODE}"
+
+rm -f ../../../alias/test-edge-empty
diff --git a/test/fast/Aliases/nvm_alias strips trailing whitespace b/test/fast/Aliases/nvm_alias strips trailing whitespace
new file mode 100755
index 0000000000..caf53bb4a9
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias strips trailing whitespace	
@@ -0,0 +1,16 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with trailing spaces and tabs
+printf '22.1.0   \t \n' > ../../../alias/test-edge-trailing-ws
+ACTUAL="$(nvm_alias test-edge-trailing-ws)"
+EXPECTED='22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+
+rm -f ../../../alias/test-edge-trailing-ws
diff --git a/test/fast/Aliases/nvm_resolve_alias handles deep chain b/test/fast/Aliases/nvm_resolve_alias handles deep chain
new file mode 100755
index 0000000000..435d35ed67
--- /dev/null
+++ b/test/fast/Aliases/nvm_resolve_alias handles deep chain	
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create a 4-deep alias chain: hop1 -> hop2 -> hop3 -> hop4 -> 0.0.99
+echo 'hop2' > ../../../alias/hop1
+echo 'hop3' > ../../../alias/hop2
+echo 'hop4' > ../../../alias/hop3
+echo '0.0.99' > ../../../alias/hop4
+
+ACTUAL="$(nvm_resolve_alias hop1)"
+EXPECTED='v0.0.99'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for 4-deep chain, got >${ACTUAL}<"
+
+rm -f ../../../alias/hop1 ../../../alias/hop2 ../../../alias/hop3 ../../../alias/hop4
diff --git a/test/fast/Aliases/nvm_resolve_alias with nonexistent target b/test/fast/Aliases/nvm_resolve_alias with nonexistent target
new file mode 100755
index 0000000000..48eb9596a7
--- /dev/null
+++ b/test/fast/Aliases/nvm_resolve_alias with nonexistent target	
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias pointing to a version that does not exist as an alias
+echo '99.99.99' > ../../../alias/test-edge-noexist
+
+ACTUAL="$(nvm_resolve_alias test-edge-noexist)"
+EXPECTED='v99.99.99'
+EXIT_CODE="$(nvm_resolve_alias test-edge-noexist >/dev/null 2>&1; echo $?)"
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+[ "${EXIT_CODE}" = '0' ] || die "expected exit code 0, got ${EXIT_CODE}"
+
+rm -f ../../../alias/test-edge-noexist

From d62de0e086efae81e2a285385ef596e3589baa2d Mon Sep 17 00:00:00 2001
From: Jake Lodwick <25925+jakelodwick@users.noreply.github.com>
Date: Wed, 18 Feb 2026 14:29:52 -0700
Subject: [PATCH 2/3] [Refactor] `nvm_alias`: use [[:space:]] instead of
 literal tab

[Tests] `nvm_alias`: add edge-case tests for hostile file content
---
 nvm.sh                                        |  5 ++---
 ...vm_alias handles alias with spaces in name | 17 ++++++++++++++
 ...vm_alias handles binary data after version | 20 +++++++++++++++++
 .../Aliases/nvm_alias handles carriage return | 22 +++++++++++++++++++
 .../Aliases/nvm_alias handles embedded NUL    | 22 +++++++++++++++++++
 ...m_alias handles form feed and vertical tab | 22 +++++++++++++++++++
 .../nvm_alias handles no trailing newline     | 16 ++++++++++++++
 .../Aliases/nvm_alias handles very long line  | 17 ++++++++++++++
 8 files changed, 138 insertions(+), 3 deletions(-)
 create mode 100755 test/fast/Aliases/nvm_alias handles alias with spaces in name
 create mode 100755 test/fast/Aliases/nvm_alias handles binary data after version
 create mode 100755 test/fast/Aliases/nvm_alias handles carriage return
 create mode 100755 test/fast/Aliases/nvm_alias handles embedded NUL
 create mode 100755 test/fast/Aliases/nvm_alias handles form feed and vertical tab
 create mode 100755 test/fast/Aliases/nvm_alias handles no trailing newline
 create mode 100755 test/fast/Aliases/nvm_alias handles very long line

diff --git a/nvm.sh b/nvm.sh
index 98ef38719a..981f3eb72d 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -1327,13 +1327,12 @@ nvm_alias() {
   while IFS= read -r NVM_ALIAS_LINE || [ -n "${NVM_ALIAS_LINE}" ]; do
     NVM_ALIAS_LINE="${NVM_ALIAS_LINE%%#*}"
     case "${NVM_ALIAS_LINE}" in
-      *[!\ \	]*) ;;
+      *[![:space:]]*) ;;
       *) continue ;;
     esac
     while : ; do
       case "${NVM_ALIAS_LINE}" in
-        *' ') NVM_ALIAS_LINE="${NVM_ALIAS_LINE% }" ;;
-        *'	') NVM_ALIAS_LINE="${NVM_ALIAS_LINE%	}" ;;
+        *[[:space:]]) NVM_ALIAS_LINE="${NVM_ALIAS_LINE%[[:space:]]}" ;;
         *) break ;;
       esac
     done
diff --git a/test/fast/Aliases/nvm_alias handles alias with spaces in name b/test/fast/Aliases/nvm_alias handles alias with spaces in name
new file mode 100755
index 0000000000..645461a833
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles alias with spaces in name	
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file whose name contains spaces
+mkdir -p ../../../alias
+printf 'v22.1.0\n' > "../../../alias/test edge spaces"
+ACTUAL="$(nvm_alias "test edge spaces")"
+EXPECTED='v22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+
+rm -f "../../../alias/test edge spaces"
diff --git a/test/fast/Aliases/nvm_alias handles binary data after version b/test/fast/Aliases/nvm_alias handles binary data after version
new file mode 100755
index 0000000000..7c9de414da
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles binary data after version	
@@ -0,0 +1,20 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file where the first line has a valid version
+# followed by a second line of binary-like data
+printf 'v22.1.0\n' > ../../../alias/test-edge-binary
+printf '\001\002\003\377\n' >> ../../../alias/test-edge-binary
+ACTUAL="$(nvm_alias test-edge-binary)"
+# nvm_alias emits every non-blank, non-comment line — first line should be the version
+FIRST_LINE="$(nvm_echo "${ACTUAL}" | command head -n 1)"
+EXPECTED='v22.1.0'
+[ "${FIRST_LINE}" = "${EXPECTED}" ] || die "expected first line >${EXPECTED}<, got >${FIRST_LINE}<"
+
+rm -f ../../../alias/test-edge-binary
diff --git a/test/fast/Aliases/nvm_alias handles carriage return b/test/fast/Aliases/nvm_alias handles carriage return
new file mode 100755
index 0000000000..ba44f1c855
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles carriage return	
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with Windows-style line endings (CRLF)
+printf 'v22.1.0\r\n' > ../../../alias/test-edge-cr
+ACTUAL="$(nvm_alias test-edge-cr)"
+EXPECTED='v22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+
+# Create an alias file with bare carriage return (no newline)
+printf 'v22.2.0\r' > ../../../alias/test-edge-cr-bare
+ACTUAL="$(nvm_alias test-edge-cr-bare)"
+EXPECTED='v22.2.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for bare CR, got >${ACTUAL}<"
+
+rm -f ../../../alias/test-edge-cr ../../../alias/test-edge-cr-bare
diff --git a/test/fast/Aliases/nvm_alias handles embedded NUL b/test/fast/Aliases/nvm_alias handles embedded NUL
new file mode 100755
index 0000000000..28b3dbb621
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles embedded NUL	
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with an embedded NUL byte after the version.
+# NUL handling varies by shell: some stop at NUL, others read through it.
+# The function must not crash, and must emit output starting with the version.
+printf 'v22.1.0\000garbage\n' > ../../../alias/test-edge-nul
+ACTUAL="$(nvm_alias test-edge-nul)"
+EXIT_CODE=$?
+[ "${EXIT_CODE}" = '0' ] || die "expected exit code 0, got ${EXIT_CODE}"
+case "${ACTUAL}" in
+  v22.1.0*) ;; # OK — starts with the version regardless of NUL handling
+  *) die "expected output starting with >v22.1.0<, got >${ACTUAL}<" ;;
+esac
+
+rm -f ../../../alias/test-edge-nul
diff --git a/test/fast/Aliases/nvm_alias handles form feed and vertical tab b/test/fast/Aliases/nvm_alias handles form feed and vertical tab
new file mode 100755
index 0000000000..c2612418a7
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles form feed and vertical tab	
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with trailing form feed
+printf 'v22.1.0\f\n' > ../../../alias/test-edge-ff
+ACTUAL="$(nvm_alias test-edge-ff)"
+EXPECTED='v22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for form feed, got >${ACTUAL}<"
+
+# Create an alias file with trailing vertical tab
+printf 'v22.2.0\v\n' > ../../../alias/test-edge-vt
+ACTUAL="$(nvm_alias test-edge-vt)"
+EXPECTED='v22.2.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for vertical tab, got >${ACTUAL}<"
+
+rm -f ../../../alias/test-edge-ff ../../../alias/test-edge-vt
diff --git a/test/fast/Aliases/nvm_alias handles no trailing newline b/test/fast/Aliases/nvm_alias handles no trailing newline
new file mode 100755
index 0000000000..c87a22ae57
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles no trailing newline	
@@ -0,0 +1,16 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with no trailing newline
+printf 'v22.1.0' > ../../../alias/test-edge-no-newline
+ACTUAL="$(nvm_alias test-edge-no-newline)"
+EXPECTED='v22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+
+rm -f ../../../alias/test-edge-no-newline
diff --git a/test/fast/Aliases/nvm_alias handles very long line b/test/fast/Aliases/nvm_alias handles very long line
new file mode 100755
index 0000000000..face2e510d
--- /dev/null
+++ b/test/fast/Aliases/nvm_alias handles very long line	
@@ -0,0 +1,17 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# Create an alias file with a very long line (version followed by a long comment)
+LONG_COMMENT="$(printf '%0*d' 10000 0 | command tr '0' 'x')"
+printf 'v22.1.0 #%s\n' "${LONG_COMMENT}" > ../../../alias/test-edge-long
+ACTUAL="$(nvm_alias test-edge-long)"
+EXPECTED='v22.1.0'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}<, got >${ACTUAL}<"
+
+rm -f ../../../alias/test-edge-long

From b763492e8e838cdedc991c7ace55d4df4ca287df Mon Sep 17 00:00:00 2001
From: Jake Lodwick <25925+jakelodwick@users.noreply.github.com>
Date: Tue, 5 May 2026 23:32:58 -0400
Subject: [PATCH 3/3] [Fix] `nvm_resolve_alias`: detect cycles via
 newline-anchored `case` [Refactor] `nvm_alias`: one-pass trailing whitespace
 strip
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The earlier commit on this branch changed SEEN_ALIASES from `\n`-delimited
storage (interpreted by `printf '%b' | nvm_grep -e "^${name}$"`) to space-
delimited but left the line-anchored grep in place — without newlines in
the haystack the anchored pattern can never match, so cycles never break.

Switch to literal-newline storage and a `case` pattern anchored on those
newlines. Newline anchoring also handles alias names containing spaces,
which token-based patterns false-positive on (e.g. lookup of `bar` matches
substring " bar " inside " foo bar midway " when the chain visits the
multi-token alias `foo bar`).

Replace the per-character trailing-whitespace loop in `nvm_alias` with a
one-pass parameter expansion, per review.

New test file covers self-loop, multi-hop loop, cycle through a
space-bearing alias name, and a non-cycle through a space-bearing
alias name. Existing `test/fast/Aliases/circular/` fixtures continue
to pass.
---
 nvm.sh                                        | 26 +++++-----
 .../Aliases/nvm_resolve_alias handles cycles  | 52 +++++++++++++++++++
 2 files changed, 66 insertions(+), 12 deletions(-)
 create mode 100755 test/fast/Aliases/nvm_resolve_alias handles cycles

diff --git a/nvm.sh b/nvm.sh
index 981f3eb72d..b4883dfc8d 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -1330,12 +1330,7 @@ nvm_alias() {
       *[![:space:]]*) ;;
       *) continue ;;
     esac
-    while : ; do
-      case "${NVM_ALIAS_LINE}" in
-        *[[:space:]]) NVM_ALIAS_LINE="${NVM_ALIAS_LINE%[[:space:]]}" ;;
-        *) break ;;
-      esac
-    done
+    NVM_ALIAS_LINE="${NVM_ALIAS_LINE%"${NVM_ALIAS_LINE##*[![:space:]]}"}"
     nvm_echo "${NVM_ALIAS_LINE}"
   done < "${NVM_ALIAS_PATH}"
 }
@@ -1373,7 +1368,9 @@ nvm_resolve_alias() {
   local ALIAS_OUTPUT
 
   local SEEN_ALIASES
-  SEEN_ALIASES=" ${ALIAS} "
+  SEEN_ALIASES="
+${ALIAS}
+"
   while true; do
     ALIAS_OUTPUT="$(nvm_alias "${ALIAS}" 2>/dev/null)" || ALIAS_OUTPUT=''
     ALIAS_TEMP="${ALIAS_OUTPUT%%
@@ -1383,12 +1380,17 @@ nvm_resolve_alias() {
       break
     fi
 
-    if command printf '%b' "${SEEN_ALIASES}" | nvm_grep -q -e "^${ALIAS_TEMP}$"; then
-      ALIAS="∞"
-      break
-    fi
+    case "${SEEN_ALIASES}" in
+      *"
+${ALIAS_TEMP}
+"*)
+        ALIAS="∞"
+        break
+      ;;
+    esac
 
-    SEEN_ALIASES="${SEEN_ALIASES}${ALIAS_TEMP} "
+    SEEN_ALIASES="${SEEN_ALIASES}${ALIAS_TEMP}
+"
     ALIAS="${ALIAS_TEMP}"
   done
 
diff --git a/test/fast/Aliases/nvm_resolve_alias handles cycles b/test/fast/Aliases/nvm_resolve_alias handles cycles
new file mode 100755
index 0000000000..3856742646
--- /dev/null
+++ b/test/fast/Aliases/nvm_resolve_alias handles cycles	
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+export NVM_DIR="$(cd ../../.. && pwd)"
+
+: nvm.sh
+\. "${NVM_DIR}/nvm.sh"
+
+# 1-hop self-reference: alias points to itself
+echo 'self' > '../../../alias/self'
+
+ACTUAL="$(nvm_resolve_alias self)"
+EXPECTED='∞'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for self-reference, got >${ACTUAL}<"
+
+rm -f '../../../alias/self'
+
+# Multi-hop loop: link1 -> link2 -> link3 -> link1
+echo 'link2' > '../../../alias/link1'
+echo 'link3' > '../../../alias/link2'
+echo 'link1' > '../../../alias/link3'
+
+ACTUAL="$(nvm_resolve_alias link1)"
+EXPECTED='∞'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for 3-hop cycle, got >${ACTUAL}<"
+
+rm -f '../../../alias/link1' '../../../alias/link2' '../../../alias/link3'
+
+# Cycle through an alias name containing a space
+echo 'midway' > '../../../alias/foo bar'
+echo 'foo bar' > '../../../alias/midway'
+
+ACTUAL="$(nvm_resolve_alias 'foo bar')"
+EXPECTED='∞'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for space-name cycle, got >${ACTUAL}<"
+
+rm -f '../../../alias/foo bar' '../../../alias/midway'
+
+# Non-cycle through an alias name containing a space.
+# Token-based cycle detection would false-positive on this chain because
+# 'bar' appears as a substring of the multi-token alias name 'foo bar'.
+# Resolves: 'foo bar' -> 'midway' -> 'bar' -> 0.0.99
+echo 'midway' > '../../../alias/foo bar'
+echo 'bar' > '../../../alias/midway'
+echo '0.0.99' > '../../../alias/bar'
+
+ACTUAL="$(nvm_resolve_alias 'foo bar')"
+EXPECTED='v0.0.99'
+[ "${ACTUAL}" = "${EXPECTED}" ] || die "expected >${EXPECTED}< for space-name chain, got >${ACTUAL}<"
+
+rm -f '../../../alias/foo bar' '../../../alias/midway' '../../../alias/bar'