errore.org

What It Is

Errore proposes an “Errors as Values” convention for TypeScript: functions do not throw exceptions, but explicitly return Error | T in their return type. Callers then check with instanceof Error or a specific error class, after which TypeScript automatically narrows the type. It is more of a coding convention; the article emphasizes that the core pattern can even be implemented with zero dependencies, while the errore package provides convenience utilities.

Core Capabilities

Functionally, Errore addresses the lack of visibility around failure paths in TypeScript projects and the ease of missing cases in catch blocks. The return signature directly exposes possible failure types, making it self-documenting. createTaggedError can create typed errors with fields and message templates, while matchError supports exhaustive matching, triggering a type error if an error branch is omitted. errore.try/tryAsync is used to wrap third-party library calls that may throw. For resource cleanup, it provides DisposableStack and AsyncDisposableStack polyfills, which work with using/await using to reduce deeply nested try/finally blocks.

Pricing and Ecosystem

The article does not provide information about commercial pricing, payment methods, or enterprise support. In terms of ecosystem, Errore is tightly coupled with the TypeScript type system and recommends using lintcn’s no-unhandled-error rule to fill the gap where TypeScript cannot detect “directly discarded Error | T return values.” The documentation also compares it with neverthrow, better-result, and Effect.ts: Errore does not use a Result container and does not require adopting a full functional framework.

Pros and Cons

Its advantages are a simple concept, lightweight dependencies, and no need for calling code to unwrap .value/.error, making it suitable for teams that want to keep ordinary TypeScript coding style. It is also friendly to library authors, as it does not force users to install a specific Result library. The downsides are that teams must accept the style of “throw less, return error values more”; complex flows may involve many if error return checks; and without lintcn integration, ignored return values may still go undetected. The article also does not mention the open-source license, maintainers, or version stability.

Who It’s For and Access from China

Errore is suitable for TypeScript library authors, Node/frontend application teams, and codebases using AI coding agents that want the compiler to enforce error-handling paths. If a team needs full runtime abstractions such as dependency injection and structured concurrency, Effect.ts is a better fit; if they prefer a traditional Result container, neverthrow is worth considering. The article does not cover access from China, so network availability and payment accessibility are both unknown.