Use version sort in `pyenv versions` if available (#2405)

libexec/pyenv-versions

@@ -123,7 +123,19 @@ if [ -n "$include_system" ] && \
 fi
 
 shopt -s dotglob nullglob
-for path in "$versions_dir"/*; do
+versions_dir_entries=("$versions_dir"/*)
+if sort --version-sort </dev/null >/dev/null 2>&1; then
+    # system sort supports version sorting
+    OLDIFS="$IFS"
+    IFS=$'\n'
+    versions_dir_entries=($(
+        printf "%s\n" "${versions_dir_entries[@]}" |
+        sort --version-sort
+    ))
+    IFS="$OLDIFS"
+fi
+
+for path in "${versions_dir_entries[@]}"; do
   if [ -d "$path" ]; then
     if [ -n "$skip_aliases" ] && [ -L "$path" ]; then
       target="$(realpath "$path")"

test/versions.bats

@@ -17,6 +17,14 @@ stub_system_python() {
   touch "$stub" && chmod +x "$stub"
 }
 
+create_executable() {
+  local name="$1"
+  local bin="${PYENV_TEST_DIR}/bin"
+  mkdir -p "$bin"
+  sed -Ee '1s/^ +//' > "${bin}/$name"
+  chmod +x "${bin}/$name"
+}
+
 @test "no versions installed" {
   stub_system_python
   assert [ ! -d "${PYENV_ROOT}/versions" ]
@@ -161,3 +169,44 @@ OUT
   run pyenv-versions --bare
   assert_success ".venv"
 }
+
+@test "sort supports version sorting" {
+  create_version "1.9.0"
+  create_version "1.53.0"
+  create_version "1.218.0"
+  create_executable sort <<SH
+#!$BASH
+if [ "\$1" == "--version-sort" ]; then
+  echo "${PYENV_ROOT}/versions/1.9.0"
+  echo "${PYENV_ROOT}/versions/1.53.0"
+  echo "${PYENV_ROOT}/versions/1.218.0"
+else exit 1
+fi
+SH
+
+  run pyenv-versions --bare
+  assert_success
+  assert_output <<OUT
+1.9.0
+1.53.0
+1.218.0
+OUT
+}
+
+@test "sort doesn't support version sorting" {
+  create_version "1.9.0"
+  create_version "1.53.0"
+  create_version "1.218.0"
+  create_executable sort <<SH
+#!$BASH
+exit 1
+SH
+
+  run pyenv-versions --bare
+  assert_success
+  assert_output <<OUT
+1.218.0
+1.53.0
+1.9.0
+OUT
+}