In the code snippet below, a new instance of ClickerApp is being created with a PlatformMock and MenuMock as parameters:
let instance = new ClickerApp((<any> new PlatformMock), (<any> new MenuMock));
This code example is taken from the following source: https://github.com/lathonez/clicker/blob/master/src/app/app.spec.ts
It appears that there is a type casting happening here. What is the purpose of this cast? Can you explain what's going on in this code snippet?
Have you heard of Type Assertion before?
Instead of calling it "type casting," it is referred to as type assertion. This is because casting usually implies runtime support, while type assertions are purely for compile-time use to guide the compiler on how to analyze your code.
Imagine you are passing mock objects instead of real ones. When you use any, it allows for unsafe assertions because it can be used with any type, causing the compiler to overlook type errors. A better approach would be to utilize interfaces (which are structurally sub-typed, similar to duck typing) and Dependency Injection (DI).
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