effect-io-ai

Package: effect
Module: Effect

Effect.timeoutFail

Specifies a custom error to be produced when a timeout occurs.

Details

This function allows you to handle timeouts in a customized way by defining a specific error to be raised when an effect exceeds the given duration. Unlike default timeout behaviors that use generic exceptions, this function gives you the flexibility to specify a meaningful error type that aligns with your application’s needs.

When you apply this function, you provide:

• A duration: The time limit for the effect.
• An onTimeout function: A lazy evaluation function that generates the custom error if the timeout occurs.

If the effect completes within the time limit, its result is returned normally. Otherwise, the onTimeout function is triggered, and its output is used as the error for the effect.

Example

import { Effect } from "effect"

const task = Effect.gen(function* () {
  console.log("Start processing...")
  yield* Effect.sleep("2 seconds") // Simulates a delay in processing
  console.log("Processing complete.")
  return "Result"
})

class MyTimeoutError {
  readonly _tag = "MyTimeoutError"
}

const program = task.pipe(
  Effect.timeoutFail({
    duration: "1 second",
    onTimeout: () => new MyTimeoutError() // Custom timeout error
  })
)

Effect.runPromiseExit(program).then(console.log)
// Output:
// Start processing...
// {
//   _id: 'Exit',
//   _tag: 'Failure',
//   cause: {
//     _id: 'Cause',
//     _tag: 'Fail',
//     failure: MyTimeoutError { _tag: 'MyTimeoutError' }
//   }
// }

See

• timeout for a version that raises a TimeoutException.
• timeoutFailCause for a version that raises a custom defect.
• timeoutTo for a version that allows specifying both success and timeout handlers.

Signature

declare const timeoutFail: { <E1>(options: { readonly onTimeout: LazyArg<E1>; readonly duration: Duration.DurationInput; }): <A, E, R>(self: Effect<A, E, R>) => Effect<A, E1 | E, R>; <A, E, R, E1>(self: Effect<A, E, R>, options: { readonly onTimeout: LazyArg<E1>; readonly duration: Duration.DurationInput; }): Effect<A, E | E1, R>; }

Source

Since v2.0.0