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Function: isInvalid()

isInvalid<T, E>(validation): validation is Invalid<E>

Defined in: validation/guards/index.ts:68

Type guard to check if a Validation is Invalid.

Narrows the type to Invalid, allowing safe access to the errors.

Type Parameters​

T​

T

E​

E

Parameters​

validation​

Validation<T, E>

The validation to check

Returns​

validation is Invalid<E>

True if the validation is Invalid

Example​

const result = invalid(['Name required', 'Email invalid'])

if (isInvalid(result)) {
  console.log(result.errors) // TypeScript knows this is safe
  // => ['Name required', 'Email invalid']
}

// Real-world: Error handling
const validation = validateForm(formData)
if (isInvalid(validation)) {
  validation.errors.forEach(err => displayError(err))
  return
}
processForm(validation.value)

See​

isValid - for checking if validation succeeded