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Function: isErr()

isErr<T, E>(result): result is Err<E>

Defined in: result/guards/index.ts:41

Type guard to check if a Result is Err.

Narrows the type to Err, allowing safe access to the error property.

Type Parameters​

T​

T

E​

E

Parameters​

result​

Result<T, E>

The Result to check

Returns​

result is Err<E>

True if the Result is Err, false otherwise

Example​

const result: Result<number, string> = err('Failed')

if (isErr(result)) {
  console.log(result.error) // TypeScript knows this is safe
}