Recently, I made the transition from coding Javascript in a functional style to using Typescript with classes for my work projects. There have been instances where I needed to ensure that there was only one instance or location for particular functionality. In these situations, I found myself torn between implementing an abstract class and using a singleton. The reasons behind my decisions seemed somewhat random and unclear, and even suggestions from my colleagues appeared vague.
Can you provide specific examples and use cases to clarify when it is appropriate to utilize an abstract class versus a singleton class versus a standard class with public static methods and properties? Hearing concrete scenarios would greatly assist in determining the best approach for each situation.
At the moment, both abstract classes and singletons seem quite similar to me, especially when dealing with creating something that should exist as a singular entity. My preference for singletons thus far has largely been due to the convenience of accessing properties directly with this.property, as opposed to having to reference them via abstractClassName.property within an abstract class, which can be more verbose. Both options appear suitable for consolidating state management, such as maintaining a shared list of timer items like items[].