services-layer

A TypeScript service layer should use pure functions, explicit dependencies, and Result-based error handling to separate business logic from UI and queries. This pattern ensures predictable, testable, and maintainable application behavior.

Defining domain-specific errors in a TypeScript service is best done using a `defineErrors` utility. This approach structures error context hierarchically, allowing clear management of specific cases like `UserNotFoundError` or `InvalidCredentialsError`.

Organize service layer code for different environments using namespace exports and platform-specific implementations. This architecture handles variations between web and desktop while maintaining a unified, predictable service interface.

Result types replace thrown exceptions in service layer architecture to enforce explicit error handling at compile time. This prevents uncaught runtime errors, making business logic predictable and domain failures consistently structured across the application.

Separate business logic into a dedicated service layer when an application requires complex, testable operations like user authentication. This separation ensures pure functions and explicit dependencies keep the codebase maintainable as domain rules grow.

Yes, the services-layer architecture pattern works without external dependencies. It relies entirely on TypeScript features and structural conventions like namespace exports to enforce pure functions and Result-based error handling.