Exposes the root mocked filesytem if the mock is currently applied. (Fixes #90)

lib/index.js

@@ -13,7 +13,6 @@ var realProcessProps = {
   chdir: process.chdir
 };
 
-
 function overrideBinding(binding) {
   for (var key in binding) {
     if (typeof binding[key] === 'function') {
@@ -30,9 +29,16 @@ function overrideProcess(cwd, chdir) {
 }
 
 function restoreBinding() {
-  for (var key in realBindingProps) {
+  var key;
+  for (key in realBindingProps) {
     realBinding[key] = realBindingProps[key];
   }
+  // Delete excess keys that came in when the binding was originally applied.
+  for (key in realBinding) {
+    if (typeof realBindingProps[key] === 'undefined') {
+      delete realBinding[key];
+    }
+  }
 }
 
 function restoreProcess() {
@@ -53,6 +59,7 @@ function restoreProcess() {
 var exports = module.exports = function mock(config, options) {
   var system = FileSystem.create(config, options);
   var binding = new Binding(system);
+
   overrideBinding(binding);
 
   var currentPath = process.cwd();
@@ -69,6 +76,17 @@ var exports = module.exports = function mock(config, options) {
   );
 };
 
+/**
+ * Get hold of the mocked filesystem's 'root'
+ * If fs hasn't currently been replaced, this will return an empty object
+ */
+exports.getMockRoot = function() {
+  if (typeof realBinding.getSystem === 'undefined') {
+    return {};
+  } else {
+    return realBinding.getSystem().getRoot();
+  }
+};
 
 /**
  * Restore the fs bindings for the real file system.

test/lib/index.spec.js

@@ -23,6 +23,14 @@ describe('The API', function() {
       mock.restore();
     });
 
+    it('provides direct access to the internal filesystem object', function() {
+      mock();
+      var root = mock.getMockRoot();
+      assert.notDeepEqual(root, {});
+      mock.restore();
+      assert.deepEqual(mock.getMockRoot(), {});
+    });
+
     it('creates process.cwd() and os.tmpdir() by default', function() {
       mock();