switch to execa - fixes #2

Author: silverwind

darwin.js

@@ -1,29 +1,38 @@
 "use strict";
 
 const net = require("net");
-const exec = require("child_process").exec;
+const execa = require("execa");
 const dests = ["default", "0.0.0.0", "0.0.0.0/0", "::", "::/0"];
 
-const get = (cmd, family) => {
-  return new Promise((resolve, reject) => {
-    exec(cmd, (err, stdout) => {
-      if (err) return reject(err);
-      (stdout || "").trim().split("\n").some(line => {
-        let target, gateway, _flags, _ref, _use, iface;
-        if (family === "v4") {
-          [target, gateway, _flags, _ref, _use, iface] = line.split(/ +/)  || [];
-        } else {
-          [target, gateway, _flags, iface] = line.split(/ +/)  || [];
-        }
-        if (dests.includes(target) && gateway && net.isIP(gateway)) {
-          resolve({gateway: gateway, interface: (iface ? iface : null)});
-          return true;
-        }
-      });
-      reject(new Error("Unable to determine default gateway"));
+const args = {
+  v4: ["-rn", "-f", "inet"],
+  v6: ["-rn", "-f", "inet6"],
+};
+
+const get = family => {
+  return execa.stdout("netstat", args[family]).then(stdout => {
+    let result;
+
+    (stdout || "").trim().split("\n").some(line => {
+      let target, gateway, _flags, _ref, _use, iface;
+      if (family === "v4") {
+        [target, gateway, _flags, _ref, _use, iface] = line.split(/ +/)  || [];
+      } else {
+        [target, gateway, _flags, iface] = line.split(/ +/)  || [];
+      }
+      if (dests.includes(target) && gateway && net.isIP(gateway)) {
+        result = {gateway: gateway, interface: (iface ? iface : null)};
+        return true;
+      }
     });
+
+    if (!result) {
+      throw new Error("Unable to determine default gateway");
+    }
+
+    return result;
   });
 };
 
-module.exports.v4 = () => get("netstat -rn -f inet", "v4");
-module.exports.v6 = () => get("netstat -rn -f inet6", "v6");
+module.exports.v4 = () => get("v4");
+module.exports.v6 = () => get("v6");

linux.js

@@ -1,23 +1,32 @@
 "use strict";
 
 const net = require("net");
-const exec = require("child_process").exec;
+const execa = require("execa");
 
-const get = cmd => {
-  return new Promise((resolve, reject) => {
-    exec(cmd, (err, stdout) => {
-      if (err) return reject(err);
-      (stdout || "").trim().split("\n").some(line => {
-        const [_, gateway, iface] = /default via (.+?) dev (.+?)( |$)/.exec(line) || [];
-        if (gateway && net.isIP(gateway)) {
-          resolve({gateway: gateway, interface: (iface ? iface : null)});
-          return true;
-        }
-      });
-      reject(new Error("Unable to determine default gateway"));
+const args = {
+  v4: ["-4", "-r"],
+  v6: ["-6", "-r"],
+};
+
+const get = family => {
+  return execa.stdout("ip", args[family]).then(stdout => {
+    let result;
+
+    (stdout || "").trim().split("\n").some(line => {
+      const [_, gateway, iface] = /default via (.+?) dev (.+?)( |$)/.exec(line) || [];
+      if (gateway && net.isIP(gateway)) {
+        result = {gateway: gateway, interface: (iface ? iface : null)};
+        return true;
+      }
     });
+
+    if (!result) {
+      throw new Error("Unable to determine default gateway");
+    }
+
+    return result;
   });
 };
 
-module.exports.v4 = () => get("ip -4 r");
-module.exports.v6 = () => get("ip -6 r");
+module.exports.v4 = () => get("v4");
+module.exports.v6 = () => get("v6");

package.json

@@ -12,6 +12,7 @@
     "node": ">=6"
   },
   "dependencies": {
+    "execa": "^0.7.0",
     "ip-regex": "^2.1.0"
   },
   "os": [

test.js

@@ -1,15 +1,15 @@
 "use strict";
 
-// travis VMs don't have IPs on their interfaces
-// https://docs.travis-ci.com/user/ci-environment/#Networking
-if (process.env.CI) return;
-
 const assert = require("assert");
 const net = require("net");
 const defaultGateway = require(".");
 
-defaultGateway.v4().then(result => {
-  assert(net.isIPv4(result.gateway));
+Promise.all([
+  defaultGateway.v4(),
+  defaultGateway.v6(),
+]).then(results => {
+  assert(net.isIPv4(results[0].gateway));
+  assert(net.isIPv6(results[1].gateway));
 }).catch(err => {
   console.error(err.stack);
   process.exit(1);

win32.js

@@ -1,38 +1,38 @@
 "use strict";
 
-const exec = require("child_process").exec;
+const execa = require("execa");
 const ipRegex = require("ip-regex");
 
 const gwCmd = "wmic path Win32_NetworkAdapterConfiguration where IPEnabled=true get DefaultIPGateway,Index /format:table";
 const ifCmd = "wmic path Win32_NetworkAdapter get Index,NetConnectionID /format:table";
 
-function wmic(proto) {
-  return new Promise((resolve, reject) => {
-    let gateway, gwid;
-    exec(gwCmd, (err, gwTable) => {
-      if (err) return reject(err);
-      exec(ifCmd, (err, ifTable) => {
-        if (err) return reject(err);
-        (gwTable || "").trim().split("\n").splice(1).some(line => {
-          const [gw, id] = line.trim().split(/} +/);
-          gateway = (ipRegex[proto]().exec((gw || "").trim()) || [])[0];
-          if (gateway) {
-            gwid = id;
-            return true;
-          }
-        });
-        (ifTable || "").trim().split("\n").splice(1).some(line => {
-          const i = line.indexOf(" ");
-          const id = line.substr(0, i).trim();
-          const name = line.substr(i + 1).trim();
-          if (id === gwid) {
-            resolve({gateway: gateway, interface: name ? name : null});
-            return true;
-          }
-        });
-        reject(new Error("Unable to determine default gateway"));
-      });
+function wmic(family) {
+  let gateway, gwid, result;
+  return execa.stdout(gwCmd, gwTable => {
+    (gwTable || "").trim().split("\n").splice(1).some(line => {
+      const [gw, id] = line.trim().split(/} +/);
+      gateway = (ipRegex[family]().exec((gw || "").trim()) || [])[0];
+      if (gateway) {
+        gwid = id;
+        return true;
+      }
     });
+  }).then(execa.stdout(ifCmd, ifTable => {
+    (ifTable || "").trim().split("\n").splice(1).some(line => {
+      const i = line.indexOf(" ");
+      const id = line.substr(0, i).trim();
+      const name = line.substr(i + 1).trim();
+      if (id === gwid) {
+        result = {gateway: gateway, interface: name ? name : null};
+        return true;
+      }
+    });
+  })).then(() => {
+    if (!result) {
+      throw new Error("Unable to determine default gateway");
+    }
+
+    return result;
   });
 }