Summary

• Introduces createForm<C> and toFormData for Solid 2.0
• Per-field signals (value, error, touched, pending), form-level signals (dirty, valid, submitting, submitted), and DOM binding via the 2.0 two-phase ref directive pattern
• Sync and async validators are first-class; validators are plain (value) => string | null | Promise<string | null> functions — no adapter needed for Zod, Valibot, Arktype, etc.
• validateOn: "change" | "blur" | "submit" controls error display timing, per field or form-wide
• Cross-field rules via form.validate(fn); server-side errors via form.setError(name, msg)
• SSR-safe: static accessors on the server, no reactive primitives created

Implementation notes (fixes applied during review)

Bug fix — async validators fired 3× per keystroke
The original architecture called each validator from three code paths per value change: once from the _rawError memo, once from the effect's sync-check, and once from the effect's collection loop. For async validators making network requests, this meant 3 API calls per keystroke with only the last result used.

Fixed by pre-classifying validators at setup time (one probe call each with fc.initial): sync validators go into a lazy syncMemo that is the only reactive subscriber to value() and never touches async validators; async validators go into asyncFns. The initial async Promises from classification are saved and reused on the first effect run if the value hasn't changed, avoiding a second API call. When async settles and asyncError() changes, _rawError recomputes by reading signals only — no validator is called. Result: async validators fire once per value change.

toFormData — false now omitted
Previously false was coerced to the string "false", which doesn't match HTML's native behavior (unchecked checkboxes are absent from form payloads). false is now omitted alongside null and undefined.

reset(newValues?) overload
Accepts an optional partial values object. Named fields adopt the new values as their dirty baseline, making edit-form patterns possible without fighting the initial-value comparison. A version counter forces dirty to recompute even when the field value and new baseline are identical (no-op signal write wouldn't invalidate the memo otherwise).

setError / field.setError
Injects an external (server-side) error into the reactive graph. Appears in field.error(), form.errors(), and gates form.valid(). Cleared automatically when the user edits the field (setValue calls the wrapped setter which clears it).

Documentation fixes

• README type definition for bind was missing | HTMLTextAreaElement
• validate() note incorrectly said "before form.valid() is first read" — the version counter handles late registration
• errors() table row now documents the exclusion of cross-field validate() errors

Summary by CodeRabbit

• New Features

  • Added a reactive form library with field-level validation, error gating, cross-field rules, async validation, DOM binding, and form submission handling.
  • Added accessibility primitives for form controls including ARIA label/description/error chaining and validation state propagation.
  • Added live region announcements for screen reader messaging.
  • Added utilities for reduced motion preferences detection.

• Documentation

  • Added comprehensive README and Storybook stories demonstrating form validation patterns, cross-field rules, async validators, and ARIA form field integration.

• Tests

  • Added full test coverage for form and accessibility functionality including SSR compatibility.