fix(karma-webpack): normalize paths to be compatible with windows

Author: igomezal

lib/karma-webpack.js

@@ -82,6 +82,8 @@ function preprocessorFactory(config, emitter) {
  controller.karmaEmitter = emitter;
  }
 
+ const normalize = (file) => file.replace(/\\/g, '/');
+
  const transformPath =
  config.webpack.transformPath ||
  ((filepath) => {
@@ -93,7 +95,7 @@ function preprocessorFactory(config, emitter) {
  return async function processFile(content, file, done) {
  await controller.bundle();
 
- file.path = transformPath(file.path); // eslint-disable-line no-param-reassign
+ file.path = normalize(transformPath(file.path)); // eslint-disable-line no-param-reassign
 
  const bundleContent = controller.bundlesContent[path.parse(file.path).base];
  done(null, bundleContent);