Skip to content
oxlint-plugin-effect

all-errors-handled-at-boundary

Intent: the entry point runs an Effect whose error channel is closed to never.

// ❌ no
export const POST = (request: Request) => Effect.runPromise(createEvent(request))


// ✅ yes: in an entry file
export const POST = (request: Request) =>
    Effect.runPromise(createEvent(request) satisfies Effect.Effect<Response, never>)


// ✅ yes: a typed helper
const runBoundary = (effect: Effect.Effect<Response, never, never>) => Effect.runPromise(effect)

Trigger: Effect.runPromise, runSync, runFork and runCallback whose argument is not … satisfies Effect.Effect<A, never>, a parameter declared with that type, or a program ending in Effect.result/Effect.exit, or the v3 Effect.either (Effect.result(program), program.pipe(…, Effect.result)).

Exemptions and blind spots: the *Exit variants, which return failures as values; NodeRuntime.runMain/BunRuntime.runMain, which log the Cause and exit with code 1, the right outcome for a process that cannot start; runners inside an async function that renders JSX itself, a Server Component, which hands failures to React rather than to an HTTP response; test files, where a rejected run fails the test with the error. The rule checks the shape; tsc gives the guarantee.

Why: Effect.runPromise turns any error left over into a rejected promise, a generic 500. With never, a new untranslated error does not compile, and R = never forces all Layers to be provided.

Options:

Fix: none