-JavaScript code has been tested with [Jasmine](https://jasmine.github.io/). Install the dependencies by [Yarn](https://yarnpkg.com/lang/en/).
-Just run `yarn`. To run the tests, switch to the `js` folder and run `yarn test`.
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+# Folder structure
+
+## NPM
+NPM in version 5.6.0 and NodeJS in version 9.11.1 are proven in building the JavaScript code. The build assumes a
+*NIX environment (Mac or Linux).
+
+## babel-compiled
+Files which are needed for tests in cli. Because [Babel](https://babeljs.io/) is transpiling the modern ES6 import
+statement to CommonJS, which can be parsed by NodeJS.
+
+## node-modules
+Third-party JavaScript libraries.
+
+## src
+The application code.
+
+## test
+Automated tests.
+
+They can be executed via command line ("bat" stands for "build and test"):
+
+`npm run bat`
+
+ Or they can be executed via the webbrowser by opening the .html files. Google Chrome
+ is good for JavaScript debugging. Therefor this option is provided by the QUnit JavaScript
+ testing tool.
+
+## Building the application
+`npm run build`
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