Prevent multiple copies of express-state from overwriting expose()

HISTORY.md

@@ -1,6 +1,24 @@
 Express State Change History
 ============================
 
+NEXT
+----
+
+* Prevented multiple copies of express-state from overwriting `expose()` when it
+  already has been plugged into a copy of express.
+
+* Added Screwdriver CI integration.
+
+
+0.0.2 (2013-05-03)
+------------------
+
+* Added Travis CI integration.
+
+* Improved namespace rendering by removing the initialization of leaf namespaces
+  since exposed values will be assigned to them. (Issue #1)
+
+
 0.0.1 (2013-05-02)
 ------------------
 

index.js

@@ -9,6 +9,14 @@ var express = require('express'),
 exports.local     = 'state';
 exports.namespace = null;
 
+// Protect against multiple copies of this module augmenting the Express
+// `application` and `response` prototypes.
+if (typeof appProto.expose === 'function' &&
+    typeof resProto.expose === 'function') {
+
+    return;
+}
+
 // Modifies Express' `application` and `response` prototypes by adding the
 // `expose()` method.
 resProto.expose = appProto.expose = function (obj, namespace, local) {

package.json

@@ -45,6 +45,7 @@
         "express3-handlebars": "*",
         "istanbul"           : "*",
         "mocha"              : "*",
+        "mockery"            : "*",
         "xunit-file"         : "*"
     },
 

test/multiple.js

@@ -0,0 +1,36 @@
+/* global describe, it, beforeEach, afterEach */
+'use strict';
+
+var expect  = require('chai').expect,
+    mockery = require('mockery');
+
+describe('multiple', function () {
+    beforeEach(function () {
+        mockery.enable({
+            useCleanCache     : true,
+            warnOnReplace     : false,
+            warnOnUnregistered: false
+        });
+
+        mockery.registerMock('express', {
+            application: {},
+            response   : {}
+        });
+    });
+
+    afterEach(function () {
+        mockery.disable();
+    });
+
+    it('should not override `expose()` if it exists', function () {
+        var expose = function () {},
+            express, state;
+
+        express = require('express');
+        express.application.expose = express.response.expose = expose;
+        state = require('../');
+
+        expect(express.application.expose).to.equal(expose);
+        expect(express.response.expose).to.equal(expose);
+    });
+});

test/state.js

@@ -1,13 +1,11 @@
 /* global describe, it, beforeEach, afterEach */
 'use strict';
 
-var state        = require('../'),
-    express      = require('express'),
-    expressUtils = require('express/lib/utils'),
+var expressUtils = require('express/lib/utils'),
     expect       = require('chai').expect,
+    express      = require('express'),
 
-    origLocal     = state.local,
-    origNamespace = state.namespace;
+    state = require('../');
 
 describe('state', function () {
     var app;
@@ -16,11 +14,6 @@ describe('state', function () {
         app = express();
     });
 
-    afterEach(function () {
-        state.local     = origLocal;
-        state.namespace = origNamespace;
-    });
-
     describe('expose()', function () {
         var expose, locals;
 
@@ -49,6 +42,16 @@ describe('state', function () {
         });
 
         describe('global .local', function () {
+            var origLocal;
+
+            beforeEach(function () {
+                origLocal = state.local;
+            });
+
+            afterEach(function () {
+                state.local = origLocal;
+            });
+
             it('should create the exposed object at the specified `local`', function () {
                 state.local = 'javascript';
                 expose();
@@ -63,6 +66,16 @@ describe('state', function () {
         });
 
         describe('global .namespace', function () {
+            var origNamespace;
+
+            beforeEach(function () {
+                origNamespace = state.namespace;
+            });
+
+            afterEach(function () {
+                state.namespace = origNamespace;
+            });
+
             it('should be used when no namespace is provided', function () {
                 state.namespace = 'App';
                 expose('foo');
@@ -98,6 +111,16 @@ describe('state', function () {
         });
 
         describe('setting: "state local"', function () {
+            var origLocal;
+
+            beforeEach(function () {
+                origLocal = state.local;
+            });
+
+            afterEach(function () {
+                state.local = origLocal;
+            });
+
             it('should use app setting', function () {
                 app.set('state local', 'javascript');
                 app.expose();
@@ -119,12 +142,29 @@ describe('state', function () {
         });
 
         describe('setting: "state namespace"', function () {
+            var origNamespace;
+
+            beforeEach(function () {
+                origNamespace = state.namespace;
+            });
+
+            afterEach(function () {
+                state.namespace = origNamespace;
+            });
+
             it('should use app setting', function () {
                 app.set('state namespace', 'App');
                 app.expose('foo');
                 expect(app.locals.state.App).to.equal('foo');
             });
 
+            it('should be preferred over the global .namespace', function () {
+                state.namespace = 'App';
+                app.set('state namespace', 'Data');
+                app.expose('foo');
+                expect(app.locals.state.Data).to.equal('foo');
+            });
+
             it('should be used as a prefix to the `namespace` provided', function () {
                 app.set('state namespace', 'App');
                 app.expose({foo: 'foo'}, 'data');