WillProvider

WillProvider is a software design pattern and library concept intended to centralize the expression of a component's intention or 'will' and to distribute that intent to interested parties within a software system. It treats the will as a first-class artifact that can be observed, negotiated, and acted upon. The core idea is to decouple the producer of intent from its consequences, enabling more modular decision-making and easier testing.

In typical implementations, a WillProvider exposes a contract or stream that communicates intents, preconditions, permissions, and desired outcomes. Consumers subscribe to these intents and respond by performing actions, validating constraints, or triggering side effects. The provider may support features such as validation, versioning of will statements, prioritization, and rollback in case a will cannot be fulfilled. It often relies on patterns such as dependency injection, event buses, or reactive streams to propagate will changes.

Common use cases include coordinating user interface components that must agree on goals, orchestrating long-running workflows, managing cross-service authorization, and facilitating test scaffolding where tests simulate will changes.

History and adoption: WillProvider is a conceptual pattern described in some literature and vendor-specific implementations. There is no universal standard or single canonical implementation, and terminology varies across ecosystems. Critics argue that introducing an explicit will layer can add indirection and potential coupling if the will contract becomes too granular or ill-defined.