This project is a test project that invokes `JavaScript` from native `Swift` code. `WKWebKit` is used to invoke `JavaScript`. Initially `JavaScript` is loaded from a web url in `String` form and evaluated using `WKWebView` instance. `Operation` enum represents a single operation which will be created using JS function `startOperation`. 4 different operations are created and 4 different progress UI elements are used to represent each operation. Progress UI elements are custom UIView's (`HorizontalProgressBar` and `CircularProgressBar`). A MessageHandler (`jumbo` here) is added to `WKWebViewConfiguration's` `userContentController` which receives the messages posted on the handler through `WKScriptMessageHandler's` delegate method `didReceive`. Upon receiving a new message, it is identified which operation this message belongs to and that operation's UI progress is updated accordingly using `handleMessage` (inside `VaccineTrialViewController`).

There are 4 unit tests added `JavaScriptTests`