fix: should return scopeid = 0 address on IPv6 (#41)

Author: fengmk2

.gitignore

@@ -19,3 +19,4 @@ npm-debug.log
 test/fixtures/ts/*.js
 .tshy*
 dist/
+package-lock.json

package.json

@@ -75,5 +75,6 @@
       }
     }
   },
-  "types": "./dist/commonjs/index.d.ts"
+  "types": "./dist/commonjs/index.d.ts",
+  "main": "./dist/commonjs/index.js"
 }

src/address.ts

@@ -58,6 +58,28 @@ function matchName(actualFamily: string | number, expectedFamily: string | numbe
   return actualFamily === expectedFamily;
 }
 
+function findAddressFromInterface(items: os.NetworkInterfaceInfo[], expectedFamily: string | number,
+  ignoreLoAddress = false) {
+  let firstMatchItem;
+  for (const item of items) {
+    if (matchName(item.family, expectedFamily)) {
+      if (ignoreLoAddress && item.address.startsWith('127.')) {
+        continue;
+      }
+      if (expectedFamily === 'IPv6') {
+        // find the scopeid = 0 item
+        if (item.scopeid === 0) return item;
+        if (!firstMatchItem) {
+          firstMatchItem = item;
+        }
+      } else {
+        return item;
+      }
+    }
+  }
+  return firstMatchItem;
+}
+
 export function getInterfaceAddress(family?: string, name?: string) {
   const interfaces = os.networkInterfaces();
   const noName = !name;
@@ -68,10 +90,9 @@ export function getInterfaceAddress(family?: string, name?: string) {
       const interfaceName = name + (i >= 0 ? i : ''); // support 'lo' and 'lo0'
       const items = interfaces[interfaceName];
       if (items) {
-        for (const item of items) {
-          if (matchName(item.family, family)) {
-            return item;
-          }
+        const item = findAddressFromInterface(items, family);
+        if (item) {
+          return item;
         }
       }
     }
@@ -82,11 +103,10 @@ export function getInterfaceAddress(family?: string, name?: string) {
     for (const k in interfaces) {
       const items = interfaces[k];
       if (items) {
-        for (const item of items) {
-          // all 127 addresses are local and should be ignored
-          if (matchName(item.family, family) && !item.address.startsWith('127.')) {
-            return item;
-          }
+        // all 127 addresses are local and should be ignored
+        const item = findAddressFromInterface(items, family, true);
+        if (item) {
+          return item;
         }
       }
     }

test/address.test.ts

@@ -232,6 +232,37 @@ describe('test/address.test.ts', () => {
       assert.equal(addressAll.ip('utun'), '10.206.52.79');
       assert.equal(addressAll.ipv6('utun'), 'fe80::696:ad3d:eeec:1722');
     });
+
+    it('should return scopeid = 0 address', () => {
+      mm(os, 'networkInterfaces', () => {
+        return {
+          lo:
+           [{ address: '127.0.0.1',
+             family: 'IPv4',
+             internal: true }],
+          utun0:
+          [
+            {
+              address: 'fe80::696:ad3d:eeec:1722',
+              family: 'IPv6',
+              internal: false,
+              scopeid: 20,
+            },
+            {
+              address: 'fe80::696:ad3d:eeee:ffff:1:1000:3380:b81a:2dd4:373e:1234',
+              family: 'IPv6',
+              internal: false,
+              scopeid: 0,
+            },
+          ],
+          utun1:
+           [{ address: '10.206.52.79',
+             family: 'IPv4',
+             internal: false }] };
+      });
+      assert.equal(addressAll.ip('utun'), '10.206.52.79');
+      assert.equal(addressAll.ipv6('utun'), 'fe80::696:ad3d:eeee:ffff:1:1000:3380:b81a:2dd4:373e:1234');
+    });
   });
 
   describe('address.dns()', () => {