# CMP-10 — An input-validation error message clears as soon as the field is corrected, with no separate action required; each field's error clears independently among multiple simultaneous errors

L1 · hybrid · Components & patterns

**Fails when:** the error message for a corrected field remains visible after the input satisfies the validation rule again · correcting one field's input clears another field's error message, or clears all errors at once · the error only clears on an unrelated action (submit, blur elsewhere, navigation) rather than on the correction itself

## Requirement

Validate a field's current value, not the fact that it was once invalid. The
moment a field's input satisfies its validation rule again, remove that
field's error message — do not wait for a submit, a blur elsewhere, or a
navigation to clear it. Where more than one field is invalid at once, clear
each field's error independently: correcting one field must never clear, or
fail to clear, any other field's error.

## Rationale

An error message is a promise about the current state of the field. A
message that outlives the error it names stops being informative and starts
being noise the user has to consciously override — "it still says I got
this wrong, but I know I fixed it." That gap between what the UI claims and
what is actually true is exactly the kind of small trust erosion daily-use
tools cannot afford. This is a real, shipped defect (see the origin PR in
`docs/catalog-changes/cmp-10-input-validation-error-clearing.md`), not a
hypothetical: it is easy to wire error state as "set true on invalid" without
a matching "set false on now-valid" path in the same handler, and the bug is
invisible in code review unless someone traces the clearing path explicitly.

## Passes when / Fails when

**Passes:**
- Typing a valid value into a field that previously showed an error removes
  that field's error message on the same input event that made it valid
  (`onChange`, not only `onBlur` or submit).
- Two fields each show independent errors; correcting field A removes only
  field A's error, and field B's error is untouched.

**Fails when:**
- The error message for a corrected field remains visible after the input
  satisfies the validation rule again.
- Correcting one field's input clears another field's error message, or
  clears every visible error at once.
- The error only clears on an unrelated action — submitting the form,
  blurring to a different field, or navigating away — rather than on the
  correction itself.

Out of scope: server-side / async validation errors, which follow CMP-3's
async-state lifecycle (loading / success / error) instead of this control.

## How to verify

Deterministic half (planned, manual until a script or interaction runner
exists): for each in-scope field, enter a value that fails validation and
confirm the error message renders; then correct the value and confirm the
error message's DOM node is gone — not merely visually hidden, unless hidden
from assistive technology too.

Judgment half: with two or more fields simultaneously invalid, correct one
and confirm only that field's error clears while the others remain visible.
Quote the field(s) and the before/after state you observed.