Function: tapInvalid()

Call Signature

tapInvalid<T, E>(validation, fn): Validation<T, E>

Defined in: validation/tap/index.ts:153

Performs a side effect with the Invalid errors, returning the validation unchanged.

Useful for logging errors, sending error reports, or triggering error handling side effects without modifying the validation.

Type Parameters

T

T

E

E

Parameters

validation

Validation<T, E>

The validation to tap

fn

(errors) => void

Side effect function called with the errors

Returns

Validation<T, E>

The original validation unchanged

Example

// Data-first
tapInvalid(invalid(['error1', 'error2']), (errors) => console.error(errors))
// Logs: ['error1', 'error2']
// Returns: Invalid(['error1', 'error2'])

tapInvalid(valid(42), (errors) => console.error(errors))
// Logs nothing
// Returns: Valid(42)

// Data-last (in pipe)
pipe(
  validateForm(formData),
  tapInvalid((errors) => logger.error('Validation failed', { errors })),
  match({
    onValid: processForm,
    onInvalid: () => showErrorPage()
  })
)

// Real-world: Error reporting
const processWithErrorReporting = (data: unknown) =>
  pipe(
    validateData(data),
    tapInvalid((errors) => {
      errorTracker.report('validation_error', {
        errors,
        context: { data }
      })
    }),
    flatMap(process)
  )

// Real-world: User feedback
const submitForm = (formData: FormData) =>
  pipe(
    validateForm(formData),
    tapInvalid((errors) => {
      showToast({
        type: 'error',
        message: `Please fix ${errors.length} error(s)`
      })
    }),
    flatMap(sendToAPI)
  )

// Real-world: Combined logging
const processWithLogging = (data: unknown) =>
  pipe(
    validateData(data),
    tap((valid) => logger.info('Validation passed', { data: valid })),
    tapInvalid((errors) => logger.error('Validation failed', { errors })),
    flatMap(process)
  )

See

tap - for side effects on Valid

Call Signature

tapInvalid<E>(fn): <T>(validation) => Validation<T, E>

Defined in: validation/tap/index.ts:157

Performs a side effect with the Invalid errors, returning the validation unchanged.

Useful for logging errors, sending error reports, or triggering error handling side effects without modifying the validation.

Type Parameters

E

E

Parameters

fn

(errors) => void

Side effect function called with the errors

Returns

The original validation unchanged

<T>(validation): Validation<T, E>

Type Parameters

T

T

Parameters

validation

Validation<T, E>

Returns

Validation<T, E>

Example

// Data-first
tapInvalid(invalid(['error1', 'error2']), (errors) => console.error(errors))
// Logs: ['error1', 'error2']
// Returns: Invalid(['error1', 'error2'])

tapInvalid(valid(42), (errors) => console.error(errors))
// Logs nothing
// Returns: Valid(42)

// Data-last (in pipe)
pipe(
  validateForm(formData),
  tapInvalid((errors) => logger.error('Validation failed', { errors })),
  match({
    onValid: processForm,
    onInvalid: () => showErrorPage()
  })
)

// Real-world: Error reporting
const processWithErrorReporting = (data: unknown) =>
  pipe(
    validateData(data),
    tapInvalid((errors) => {
      errorTracker.report('validation_error', {
        errors,
        context: { data }
      })
    }),
    flatMap(process)
  )

// Real-world: User feedback
const submitForm = (formData: FormData) =>
  pipe(
    validateForm(formData),
    tapInvalid((errors) => {
      showToast({
        type: 'error',
        message: `Please fix ${errors.length} error(s)`
      })
    }),
    flatMap(sendToAPI)
  )

// Real-world: Combined logging
const processWithLogging = (data: unknown) =>
  pipe(
    validateData(data),
    tap((valid) => logger.info('Validation passed', { data: valid })),
    tapInvalid((errors) => logger.error('Validation failed', { errors })),
    flatMap(process)
  )

See

tap - for side effects on Valid