Merge pull request #4 from WindowsAzure/release-0.0.2

Release 0.0.2 merge to master

README.md

@@ -72,3 +72,28 @@ c3.configure('production', function (c) {
   c.useSql('realDatabase', 'actualDb');
 });
 ```
+
+Are you making changes to a global configuration in your unit tests, and want
+to ensure you've restored the state after your test? Use a snapshot:
+
+```javascript
+
+var c4 = envconf.createConfig();
+c4.configure(function (c) {
+  c.set('originalValue', 'one');
+});
+
+// set up contents of c4
+
+var snapshot = c4.snapshot();
+
+c4.configure(function (c) {
+  c.set('originalValue', 'two');
+});
+
+c4.restore(snapshot);
+
+c4.get('originalValue').should.equal('one');
+```
+
+Snapshot/restore also saves and restores any child configurations.

lib/index.js

@@ -15,6 +15,20 @@
 
 'use strict';
 
+function Snapshot(settings, environments) {
+  var self = this;
+  self.settings = {};
+  self.environments = {};
+
+  Object.keys(settings).forEach(function (key) {
+    self.settings[key] = settings[key];
+  });
+
+  Object.keys(environments).forEach(function (key) {
+    self.environments[key] = environments[key].snapshot();
+  });
+}
+
 function Config(parent, defaultEnvVar, customizer) {
   var environments = { };
   var settings = { };
@@ -60,6 +74,23 @@ function Config(parent, defaultEnvVar, customizer) {
     return settings.hasOwnProperty(setting) || (!!parent && parent.has(setting));
   };
 
+  config.snapshot = function () {
+    return new Snapshot(settings, environments);
+  };
+
+  config.restore = function (snapshot) {
+    if (!(snapshot instanceof Snapshot)) {
+      throw new Error('Invalid snapshot');
+    }
+
+    settings = snapshot.settings;
+
+    environments = {};
+    Object.keys(snapshot.environments).forEach(function (key) {
+      config(key).restore(snapshot.environments[key]);
+    });
+  };
+
   Object.defineProperties(config, {
     default: {
       get: function () {

package.json

@@ -6,7 +6,7 @@
     "Rodrigues, Andre <andrerod@microsoft.com>",
     "Tavares, Chris <ctavares@microsoft.com>"
   ],
-  "version": "0.0.1",
+  "version": "0.0.2",
   "description": "a module for express-style programmatic configuration",
   "main": "lib/index.js",
   "tags": ["config", "environment"],

test/config-test.js

@@ -280,3 +280,55 @@ describe('Config customization', function () {
     spy.callCount.should.equal(2);
   });
 });
+
+describe('Snapshot and restore', function () {
+  it('should save and restore configuration state', function () {
+    var c = envconf.createConfig();
+    c.configure(function () {
+      c.set('first', 'one');
+      c.set('second', 'two');
+    });
+
+    var ss = c.snapshot();
+    c.set('first', 'changed');
+    c.set('added', 'new value');
+
+    c.restore(ss);
+
+    c.get('first').should.equal('one');
+    c.get('second').should.equal('two');
+    should.not.exist(c.get('added'));
+  });
+
+  it('should save and restore child environments', function () {
+    var c = envconf.createConfig();
+    c.configure('dev', function (dev) {
+      dev.set('devFirst', 'one');
+      dev.configure('devsub', function (devsub) {
+        devsub.set('subsubFirst', 'a sub sub value');
+      });
+    });
+
+    c.configure('prod', function (prod) {
+      prod.set('prodvalue', 'a value');
+    });
+
+    var snapshot = c.snapshot();
+
+    c('dev').set('devFirst', 'changed value');
+    c('prod').configure('addedEnvironment', function (added) {
+      added.set('newEnvValue', 1234);
+    });
+
+    c.restore(snapshot);
+
+    c('dev').get('devFirst').should.equal('one');
+    c('prod').environments.should.not.include('addedEnvironment');
+  });
+
+  it('should fail if trying to restore an invalid snapshot', function () {
+    var c = envconf.createConfig();
+
+    (function () { c.restore([{}, {}]); }).should.throw();
+  });
+});