Question

I’ve got a simple function like this:

    function CreateFileLink()     {             global $Username;              return date('d-m-y-g-i');     } 

How do you write code to test a function like that where the return data is variable?

Answer 1

You could test it if you could somehow get control over that date() function. For example, in this case, you only care that the date function is being called with ‘d-m-y-g-i’; you don’t really care about the output of it. Maybe something like:

function CreateFileLink(DateProvider dateProvider) {         global $Username;          return dateProvider.date('d-m-y-g-i'); } 

Sorry, I don’t even know what language this is but hopefully you can see my point. In production code, you’d call this by doing:

DateProvider standardDateProvider = new DateProvider() { Date date(String str) { return date(str); } }; CreateFileLink(standardDateProvider); 

But in your test, you can provide an alternate implementation that will throw an error if the input isn’t what you expect:

DateProvider mockProvider = new DateProvider()  {     Date date(String str)      {         if(str != 'd-m-y-g-i') throw Exception();         return 'success';     } }