Fluent Interface
A fluent interface is a software design pattern that enables method chaining to create more readable and expressive code, often resembling a domain-specific language (DSL). It allows developers to call multiple methods in a single statement by having each method return an object (often 'this') that supports further method calls. This pattern is commonly used in APIs, query builders, and configuration objects to improve code clarity and reduce boilerplate.
Developers should use fluent interfaces when designing APIs or libraries where readability and ease of use are priorities, such as in query builders (e.g., LINQ in C#), configuration setups, or testing frameworks. It helps create intuitive code that flows naturally, making it easier to understand and maintain, especially in complex operations that involve multiple steps or settings. However, it should be applied judiciously to avoid overcomplicating simple interfaces or violating the principle of least astonishment.