test: fix IPv6 checks on IBM i

Author: abmusse

test/common/index.js

@@ -940,7 +940,14 @@ const common = {
 
   get hasIPv6() {
     const iFaces = require('os').networkInterfaces();
-    const re = isWindows ? /Loopback Pseudo-Interface/ : /lo/;
+    let re;
+    if (isWindows) {
+      re = /Loopback Pseudo-Interface/;
+    } else if (this.isIBMi) {
+      re = /\*LOOPBACK/;
+    } else {
+      re = /lo/;
+    }
     return Object.keys(iFaces).some((name) => {
       return re.test(name) &&
              iFaces[name].some(({ family }) => family === 'IPv6');

test/parallel/test-net-autoselectfamily.js

@@ -217,6 +217,10 @@ if (common.hasIPv6) {
           assert.strictEqual(error.message, `connect ECONNREFUSED ::1:${port}`);
         } else if (error.code === 'EAFNOSUPPORT') {
           assert.strictEqual(error.message, `connect EAFNOSUPPORT ::1:${port} - Local (undefined:undefined)`);
+        } else if (common.isIBMi) {
+          // IBMi returns EUNATCH (ERRNO 42) when IPv6 is disabled
+          // keep this errno assertion until EUNATCH is recognized by libuv
+          assert.strictEqual(error.errno, -42);
         } else {
           assert.strictEqual(error.code, 'EADDRNOTAVAIL');
           assert.strictEqual(error.message, `connect EADDRNOTAVAIL ::1:${port} - Local (:::0)`);