fix: should double check 0.0.0.0 and localhost (#20)

should check current ip too

- closes #17
- closes #19

lib/detect-port.js

@@ -2,6 +2,7 @@
 
 const debug = require('debug')('detect-port');
 const net = require('net');
+const address = require('address');
 
 module.exports = (port, callback) => {
   if (typeof port === 'function') {
@@ -26,28 +27,58 @@ module.exports = (port, callback) => {
 };
 
 function tryListen(port, maxPort, callback) {
-  const server = new net.Server();
-
-  server.on('error', err => {
-    debug('listen %s error: %s', port, err);
-    if (port === 0) {
-      return callback(err);
-    }
-
+  function handleError() {
     port++;
     if (port >= maxPort) {
       debug('port: %s >= maxPort: %s, give up and use random port', port, maxPort);
       port = 0;
       maxPort = 0;
     }
+    tryListen(port, maxPort, callback);
+  }
+
+  // 1. check 0.0.0.0
+  listen(port, null, (err, realPort) => {
+    // ignore random listening
+    if (port === 0) {
+      return callback(err, realPort);
+    }
+
+    if (err) {
+      return handleError(err);
+    }
+
+    // 2. check localhost
+    listen(port, 'localhost', err => {
+      if (err) {
+        return handleError(err);
+      }
+
+      // 3. check current ip
+      listen(port, address.ip(), (err, realPort) => {
+        if (err) {
+          return handleError(err);
+        }
+
+        callback(null, realPort);
+      });
+    });
+  });
+}
+
+function listen(port, hostname, callback) {
+  const server = new net.Server();
+
+  server.on('error', err => {
+    debug('listen %s:%s error: %s', hostname, port, err);
     server.close();
-    return tryListen(port, maxPort, callback);
+    return callback(err);
   });
 
-  server.listen({ port }, () => {
+  server.listen(port, hostname, () => {
     port = server.address().port;
     server.close();
-    debug('get free port: %s', port);
-    callback(null, port);
+    debug('get free %s:%s', hostname, port);
+    return callback(null, port);
   });
 }

package.json

@@ -16,6 +16,7 @@
     "url": "git://github.com/node-modules/detect-port.git"
   },
   "dependencies": {
+    "address": "^1.0.1",
     "debug": "^2.6.0"
   },
   "devDependencies": {

test/detect-port.test.js

@@ -3,18 +3,30 @@
 const assert = require('assert');
 const net = require('net');
 const pedding = require('pedding');
+const address = require('address');
 const detectPort = require('..');
 
 describe('detect port test', () => {
   const servers = [];
   before(done => {
-    done = pedding(11, done);
+    done = pedding(12, done);
     const server = new net.Server();
-    server.listen(3000, done);
+    server.listen(3000, 'localhost', done);
     servers.push(server);
+
+    const server2 = new net.Server();
+    server2.listen(4000, address.ip(), done);
+    servers.push(server2);
+
     for (let port = 7000; port < 7010; port++) {
       const server = new net.Server();
-      server.listen(port, done);
+      if (port % 3 === 0) {
+        server.listen(port, done);
+      } else if (port % 3 === 1) {
+        server.listen(port, 'localhost', done);
+      } else {
+        server.listen(port, address.ip(), done);
+      }
       servers.push(server);
     }
   });
@@ -37,14 +49,22 @@ describe('detect port test', () => {
     });
   });
 
-  it('work with listening next port 3001', done => {
+  it('work with listening next port 3001 because 3000 was listen by localhost', done => {
     const port = 3000;
     detectPort(port, (_, realPort) => {
       assert(realPort === 3001);
       done();
     });
   });
 
+  it('work with listening next port 4001 because 4000 was listen by ' + address.ip(), done => {
+    const port = 4000;
+    detectPort(port, (_, realPort) => {
+      assert(realPort === 4001);
+      done();
+    });
+  });
+
   it('work with listening random port when try port hit maxPort', done => {
     const port = 7000;
     detectPort(port, (_, realPort) => {