test(INET): test for unzero6 bash function

tests/unzero6.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+# Source the config to get unzero6()
+# shellcheck source=/dev/null
+. "$ROOT_DIR/etc/rc.d/rc.inet1.conf"
+
+pass_count=0
+fail_count=0
+
+assert_eq() {
+  local input="$1"
+  local expected="$2"
+  local output
+
+  output="$(unzero6 "$input" || true)"
+
+  if [[ "$output" == "$expected" ]]; then
+    printf "PASS: %s -> %s\n" "$input" "$output"
+    pass_count=$((pass_count + 1))
+  else
+    printf "FAIL: %s -> %s (expected %s)\n" "$input" "$output" "$expected"
+    fail_count=$((fail_count + 1))
+  fi
+}
+
+# Basic normalization
+assert_eq "2001:0db8:0001:0000:0000:0000:0000:0001" "2001:db8:1:0:0:0:0:1"
+assert_eq "fe80:0000:0000:0000:0202:b3ff:fe1e:8329" "fe80:0:0:0:202:b3ff:fe1e:8329"
+
+# Middle :: handling
+assert_eq "2001:db8::1" "2001:db8::1"
+assert_eq "2001:0db8:0001::0020" "2001:db8:1::20"
+assert_eq "2001:db8:1::20" "2001:db8:1::20"
+
+# Trailing :: handling
+assert_eq "2001:db8:11:53::" "2001:db8:11:53::"
+
+# Leading :: handling
+assert_eq "::1" "::1"
+assert_eq "::" "::"
+
+# No compression
+assert_eq "2001:db8:1:2:3:4:5:6" "2001:db8:1:2:3:4:5:6"
+
+# Mixed case hex
+assert_eq "2001:DB8:0Aa:0:0:0:0:1" "2001:db8:aa:0:0:0:0:1"
+
+printf "\nSummary: %d passed, %d failed\n" "$pass_count" "$fail_count"
+if [[ $fail_count -ne 0 ]]; then
+  exit 1
+fi