Defensive coding is a programming practice that helps make TypeScript applications more reliable and robust. It involves checking input data for errors, handling errors gracefully, respecting data boundaries, enforcing assumptions, and providing fail-safe defaults. By following these principles, developers can reduce the risk of bugs and security vulnerabilities.
Function overloading in TypeScript allows you to define multiple functions with the same name but different parameters. This can be useful when you want to provide different behavior based on the arguments passed to the function. By using function overloading, you can improve the return types of your functions for different input scenarios.
An assertion function is a runtime check that identifies the type of unknown input. TypeScript's compiler assumes the input is of the type claimed by the assertion function's signature. Assertion functions are useful for uncertain values, like user input, and generate runtime checks. They can raise errors if the input doesn't meet criteria.