<E>(self: Cause<E>): booleanReturns true if the cause contains at least one Fail reason.
When to use
Use to check whether a cause includes typed failures before extracting, mapping, or rendering them.
Example (Checking for typed errors)
import { Cause } from "effect"
console.log(Cause.hasFails(Cause.fail("error"))) // true
console.log(Cause.hasFails(Cause.die("defect"))) // falseexport const const hasFails: <E>(
self: Cause<E>
) => boolean
Returns true if the cause contains at least one Fail reason.
When to use
Use to check whether a cause includes typed failures before extracting,
mapping, or rendering them.
Example (Checking for typed errors)
import { Cause } from "effect"
console.log(Cause.hasFails(Cause.fail("error"))) // true
console.log(Cause.hasFails(Cause.die("defect"))) // false
hasFails: <function (type parameter) E in <E>(self: Cause<E>): booleanE>(self: Cause<E>(parameter) self: {
reasons: ReadonlyArray<Reason<E>>;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <E>(self: Cause<E>): booleanE>) => boolean = import effecteffect.const hasFails: <E>(
self: Cause.Cause<E>
) => boolean