Added unloading files feature from require cache

lib/mocha.js

@@ -236,6 +236,24 @@ Mocha.prototype.ui = function(name) {
   return this;
 };
 
+/**
+ * Unload test file.
+ *
+ * @api public
+ */
+Mocha.prototype.unloadFile = function(filePath) {
+  delete require.cache[require.resolve(filePath)];
+};
+
+/**
+ * Unload all test files.
+ *
+ * @api public
+ */
+Mocha.prototype.unloadFiles = function() {
+  this.files.forEach(this.unloadFile);
+};
+
 /**
  * Load registered files.
  *

test/node-unit/mocha.spec.js

@@ -0,0 +1,43 @@
+'use strict';
+
+var Mocha = require('../../lib/mocha');
+var Path = require('path');
+
+describe('.unloadFile()', function() {
+  it('should load and unload file to/from cache', function() {
+    var mocha = new Mocha({});
+    var filePath = __filename;
+
+    mocha.addFile(filePath);
+    mocha.loadFiles();
+
+    expect(require.cache, 'to have property', require.resolve(filePath));
+    mocha.unloadFile(filePath);
+    expect(require.cache, 'not to have property', require.resolve(filePath));
+  });
+});
+
+describe('.unloadFiles()', function() {
+  it('should unload all test files from cache', function() {
+    var mocha = new Mocha({});
+    var testFiles = [
+      __filename,
+      Path.join(__dirname, 'fs.spec.js'),
+      Path.join(__dirname, 'color.spec.js')
+    ];
+
+    testFiles.forEach(function(file) {
+      mocha.addFile(file);
+    });
+
+    mocha.loadFiles();
+    testFiles.forEach(function(file) {
+      expect(require.cache, 'to have property', require.resolve(file));
+    });
+
+    mocha.unloadFiles();
+    testFiles.forEach(function(file) {
+      expect(require.cache, 'not to have property', require.resolve(file));
+    });
+  });
+});