[api test] Update nconf.Provider to create a new instance of the store if the options are different

lib/nconf/provider.js

@@ -26,9 +26,21 @@ var Provider = exports.Provider = function (options) {
 // specified `type`.
 //
 Provider.prototype.use = function (type, options) {
-  if (!this.store || type.toLowerCase() !== this.store.type) {
+  var self = this;
+  options = options || {};
+
+  function sameOptions () {
+    return Object.keys(options).every(function (key) {
+      return options[key] === self.store[key];
+    });
+  }
+  
+  if (!this.store || type.toLowerCase() !== this.store.type 
+    || !sameOptions()) {
     this.store = stores.create(type, options);
   }
+  
+  return this;
 };
 
 //

test/provider-test.js

@@ -0,0 +1,32 @@
+/*
+ * file-store-test.js: Tests for the nconf File store.
+ *
+ * (C) 2011, Charlie Robbins
+ *
+ */
+
+var fs = require('fs'),
+    path = require('path'),
+    vows = require('vows'),
+    assert = require('assert'),
+    nconf = require('../lib/nconf')
+
+var first = '/path/to/file1',
+    second = '/path/to/file2';
+
+vows.describe('nconf/provider').addBatch({
+  "When using an instance of nconf.Provier": {
+    "calling the use() method with the same store type and different options": {
+      topic: new nconf.Provider().use('file', { file: first }),
+      "should use a new instance of the store type": function (provider) {
+        var old = provider.store;
+
+        assert.equal(provider.store.file, first);
+        provider.use('file', { file: second });
+
+        assert.notStrictEqual(old, provider.store);
+        assert.equal(provider.store.file, second);
+      }
+    }
+  }
+}).export(module);