Remove coercion from port check

lib/application.js

@@ -7,6 +7,7 @@ var DataSource = require('loopback-datasource-juggler').DataSource
   , compat = require('./compat')
   , assert = require('assert')
   , fs = require('fs')
+  , _ = require('underscore')
   , RemoteObjects = require('strong-remoting')
   , swagger = require('strong-remoting/ext/swagger')
   , stringUtils = require('underscore.string')
@@ -431,15 +432,16 @@ app.boot = function(options) {
     process.env.npm_package_config_host ||
     app.get('host');
 
-  appConfig.port = 
-    process.env.npm_config_port ||
-    process.env.OPENSHIFT_SLS_PORT ||
-    process.env.OPENSHIFT_NODEJS_PORT ||
-    process.env.PORT ||
-    appConfig.port ||
-    process.env.npm_package_config_port ||
-    app.get('port') || 
-    3000;
+  appConfig.port = _.find([
+    process.env.npm_config_port,
+    process.env.OPENSHIFT_SLS_PORT,
+    process.env.OPENSHIFT_NODEJS_PORT,
+    process.env.PORT,
+    appConfig.port,
+    process.env.npm_package_config_port,
+    app.get('port'),
+    3000
+  ], _.isFinite);
 
   appConfig.restApiRoot =
     appConfig.restApiRoot ||

test/app.test.js

@@ -189,6 +189,12 @@ describe('app', function() {
         var app = this.boot();
         assert.equal(app.get('host'), process.env.npm_config_host);
 
+        delete process.env.npm_config_host;
+        delete process.env.OPENSHIFT_SLS_IP;
+        delete process.env.OPENSHIFT_NODEJS_IP;
+        delete process.env.HOST;
+        delete process.env.npm_package_config_host;
+
         process.env.npm_config_port = randomPort();
         process.env.OPENSHIFT_SLS_PORT = randomPort();
         process.env.OPENSHIFT_NODEJS_PORT = randomPort();
@@ -198,6 +204,12 @@ describe('app', function() {
         var app = this.boot();
         assert.equal(app.get('host'), process.env.npm_config_host);
         assert.equal(app.get('port'), process.env.npm_config_port);
+
+        delete process.env.npm_config_port;
+        delete process.env.OPENSHIFT_SLS_PORT;
+        delete process.env.OPENSHIFT_NODEJS_PORT;
+        delete process.env.PORT;
+        delete process.env.npm_package_config_port;
       });
 
       function randomHost() {
@@ -207,6 +219,18 @@ describe('app', function() {
       function randomPort() {
         return Math.floor(Math.random() * 10000);
       }
+
+      it('should honor 0 for free port', function () {
+        var app = loopback();
+        app.boot({app: {port: 0}});
+        assert.equal(app.get('port'), 0);
+      });
+
+      it('should default to port 3000', function () {
+        var app = loopback();
+        app.boot({app: {port: undefined}});
+        assert.equal(app.get('port'), 3000);
+      });
     });
 
     it('Instantiate models', function () {