effect-io-ai

Package: effect
Module: Effect

Effect.matchCauseEffect

Handles failures with access to the cause and allows performing side effects.

Details

The matchCauseEffect function works similarly to matchCause, but it also allows you to perform additional side effects based on the failure cause. This function provides access to the complete cause of the failure, making it possible to differentiate between various failure types, and allows you to respond accordingly while performing side effects (like logging or other operations).

Example (Handling Different Failure Causes with Side Effects)

import { Effect, Console } from "effect"

const task: Effect.Effect<number, Error> = Effect.die("Uh oh!")

const program = Effect.matchCauseEffect(task, {
  onFailure: (cause) => {
    switch (cause._tag) {
      case "Fail":
        // Handle standard failure with a logged message
        return Console.log(`Fail: ${cause.error.message}`)
      case "Die":
        // Handle defects (unexpected errors) by logging the defect
        return Console.log(`Die: ${cause.defect}`)
      case "Interrupt":
        // Handle interruption and log the fiberId that was interrupted
        return Console.log(`${cause.fiberId} interrupted!`)
    }
    // Fallback for other causes
    return Console.log("failed due to other causes")
  },
  onSuccess: (value) =>
    // Log success if the task completes successfully
    Console.log(`succeeded with ${value} value`)
})

Effect.runPromise(program)
// Output: "Die: Uh oh!"

See

• matchCause if you don’t need side effects and only want to handle the result or failure.
• matchEffect if you don’t need to handle the cause of the failure.

Signature

declare const matchCauseEffect: { <E, A2, E2, R2, A, A3, E3, R3>(options: { readonly onFailure: (cause: Cause.Cause<E>) => Effect<A2, E2, R2>; readonly onSuccess: (a: A) => Effect<A3, E3, R3>; }): <R>(self: Effect<A, E, R>) => Effect<A2 | A3, E2 | E3, R2 | R3 | R>; <A, E, R, A2, E2, R2, A3, E3, R3>(self: Effect<A, E, R>, options: { readonly onFailure: (cause: Cause.Cause<E>) => Effect<A2, E2, R2>; readonly onSuccess: (a: A) => Effect<A3, E3, R3>; }): Effect<A2 | A3, E2 | E3, R2 | R3 | R>; }

Source

Since v2.0.0