# @lpm.dev/neo.react-forms

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> Modern, performant React form library - 78% smaller than Formik, perfect TypeScript inference

- Version: 1.0.0
- Ecosystem: JavaScript
- Distribution: pool
- License: MIT
- Homepage: https://github.com/ne-ooo/neo.react-forms#readme
- Repository: https://github.com/ne-ooo/neo.react-forms

## Install

```bash
lpm install @lpm.dev/neo.react-forms
```

## Agent quick reference

A high-performance, zero-dependency React form library with perfect TypeScript inference, field-level re-render isolation, and 36+ built-in validators.

### Quick start

```js
import { useForm } from '@lpm.dev/neo.react-forms';

const form = useForm({
  initialValues: { email: '', password: '' },
  validate: {
    email: (value) => !value ? 'Required' : null,
    password: (value) => value.length < 8 ? 'Too short' : null
  },
  onSubmit: async (values) => { await api.submit(values); }
});
```

### Key exports

- `useForm` (function): Main hook for form state management with validation, submission, and field-level subscriptions. — `<Values extends Record<string, unknown>>(options: UseFormOptions<Values>) => UseFormReturn<Values>`
- `required` (function): Validator that checks if field has a value. — `(message?: string) => Validator<string>`
- `email` (function): Validator that checks if value is a valid email format. — `(message?: string) => Validator<string>`
- `minLength` (function): Validator that checks minimum string length. — `(min: number, message?: string) => Validator<string>`
- `maxLength` (function): Validator that checks maximum string length. — `(max: number, message?: string) => Validator<string>`
- `min` (function): Validator that checks minimum numeric value. — `(minValue: number, message?: string) => Validator<number>`
- `max` (function): Validator that checks maximum numeric value. — `(maxValue: number, message?: string) => Validator<number>`
- `pattern` (function): Validator that checks value against a regex pattern. — `(pattern: RegExp, message?: string) => Validator<string>`
- `compose` (function): Combines multiple validators, returning the first error found. — `<T, Values = unknown>(validators: Validator<T, Values>[]) => Validator<T, Values>`
- `optional` (function): Wraps a validator to skip validation for empty/null/undefined values. — `<T, Values = unknown>(validator: Validator<T, Values>) => Validator<T | null | undefined, Values>`
- `when` (function): Conditional validator that only runs when condition is true. — `<T, Values = unknown>(condition: (value: T, values?: Values) => boolean, validator: Validator<T, Values>) => Validator<T, Values>`
- `custom` (function): Create a custom validator with sync or async validation function. — `<T, Values = unknown>(validate: (value: T, values?: Values) => string | null | Promise<string | null>) => Validator<T, Values>`
- `zodAdapter` (function): Convert a Zod schema to a ValidationSchema for use with useForm. — `<T extends ZodObject>(schema: T) => ValidationSchema<ZodInfer<T>>`
- `zodForm` (function): Convenience helper that combines Zod schema with initial values for useForm. — `<T extends ZodObject>(schema: T, initialValues: ZodInfer<T>) => { initialValues: ZodInfer<T>; validate: ValidationSchema<ZodInfer<T>> }`
- `getFieldAriaProps` (function): Generate ARIA attributes for accessible form fields. — `(options: { name: string; hasError?: boolean; isRequired?: boolean; errorId?: string; descriptionId?: string }) => A11yFieldProps`

### Basic form with built-in validators

Use compose() to combine multiple validators on a single field.

```js
import { useForm } from '@lpm.dev/neo.react-forms';
import { required, email, minLength, compose } from '@lpm.dev/neo.react-forms/validators';

const form = useForm({
  initialValues: { email: '', password: '' },
  validate: {
    email: compose([required('Email required'), email('Invalid email')]),
    password: minLength(8, 'Must be 8+ characters')
  },
  onSubmit: async (values) => { await api.login(values); }
});
```

### Form with Zod schema validation

Use Zod schemas for validation with automatic type inference. Requires zod as peer dependency.

```js
import { useForm } from '@lpm.dev/neo.react-forms';
import { zodForm } from '@lpm.dev/neo.react-forms/adapters';
import { z } from 'zod';

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8)
});

const form = useForm({
  ...zodForm(schema, { email: '', password: '' }),
  onSubmit: async (values) => { await api.login(values); }
});
```

### Conditional validation

Use when() to conditionally apply validation based on other field values.

```js
import { when, required } from '@lpm.dev/neo.react-forms/validators';

const form = useForm({
  initialValues: { usePromo: false, promoCode: '' },
  validate: {
    promoCode: when(
      (value, values) => values.usePromo,
      required('Promo code required when promo is selected')
    )
  },
  onSubmit: async (values) => { await api.submit(values); }
});
```

### Async validation with debounce

Use debounceValidator for async validation (e.g., checking username availability) to avoid excessive API calls.

```js
import { debounceValidator } from '@lpm.dev/neo.react-forms/validators';

const checkUsername = debounceValidator(async (username) => {
  const res = await fetch(`/api/check-username?u=${username}`);
  const { exists } = await res.json();
  return exists ? 'Username already taken' : null;
}, 500);

const form = useForm({
  initialValues: { username: '' },
  validate: { username: checkUsername },
  onSubmit: async (values) => { await api.signup(values); }
});
```

### Accessible form field rendering

Generate ARIA attributes for screen reader support and accessibility compliance.

```js
import { getFieldAriaProps, generateFieldIds } from '@lpm.dev/neo.react-forms';

const { errorId, descriptionId } = generateFieldIds('email');
const ariaProps = getFieldAriaProps({
  name: 'email',
  hasError: !!form.errors.email,
  isRequired: true,
  errorId
});

// Use in JSX: <input {...field} {...ariaProps} />
```

### Gotchas

- Package name is '@lpm.dev/neo.react-forms' (not 'react-forms') - use full scoped name.
- Validators must be imported from '@lpm.dev/neo.react-forms/validators' subpath, not the main export.
- Zod adapters require 'zod' as a peer dependency and are imported from '@lpm.dev/neo.react-forms/adapters'.
- Field paths use dot notation for nested values: 'user.profile.name' not ['user', 'profile', 'name'].
- Validators return string | null (error message or null for valid), not boolean.

## README

# @lpm.dev/neo.react-forms

**The fastest, smallest, and most performant React form library.**

---

## Why neo.react-forms?

- ⚡ **Blazing Fast**: 366,000+ ops/sec, 27-115% faster than alternatives
- 📦 **Tiny Bundle**: 7.1 KB gzipped (96% smaller than Formik, 83% smaller than RHF)
- 🎯 **Perfect TypeScript**: Zero manual generics, full path autocomplete
- 🔒 **Zero Dependencies**: No runtime dependencies
- 🎨 **Zero Re-renders**: Perfect field isolation with \`useSyncExternalStore\`
- 🌳 **Tree-Shakeable**: Import only what you need
- ✅ **Comprehensive**: 36 built-in validators, Zod adapter, DevTools
- 💾 **Memory Efficient**: Zero memory leaks, < 10 MB for 100+ field forms

---

## Quick Start

### Installation

```bash
lpm install @lpm.dev/neo.react-forms
```

### Basic Example

```tsx
import { useForm } from "@lpm.dev/neo.react-forms";

function SignupForm() {
  const form = useForm({
    initialValues: {
      email: "",
      password: "",
    },
    validate: {
      email: (value) => (value.includes("@") ? undefined : "Invalid email"),
      password: (value) => (value.length >= 8 ? undefined : "Too short"),
    },
    onSubmit: async (values) => {
      await api.signup(values);
    },
  });

  return (
    <form onSubmit={form.handleSubmit}>
      <form.Field name="email">
        {({ field, error, touched }) => (
          <div>
            <input type="email" {...field} />
            {touched && error && <span>{error}</span>}
          </div>
        )}
      </form.Field>

      <form.Field name="password">
        {({ field, error, touched }) => (
          <div>
            <input type="password" {...field} />
            {touched && error && <span>{error}</span>}
          </div>
        )}
      </form.Field>

      <button type="submit" disabled={form.isSubmitting}>
        Sign Up
      </button>
    </form>
  );
}
```

---

## Features

### 🎯 Perfect TypeScript Inference

**Zero manual generics needed**. TypeScript infers everything from `initialValues`:

```tsx
const form = useForm({
  initialValues: {
    user: {
      email: "",
      profile: {
        name: "",
        age: 0,
      },
    },
  },
});

// ✅ Full autocomplete for nested paths
form.setValue("user.profile.name", "John");

// ✅ Type checking for values
form.setValue("user.profile.age", "25"); // Error!
```

### ⚡ Zero Re-renders

Unlike Formik which re-renders all fields on every change, **neo.react-forms** only re-renders the field that changed:

```tsx
// Updating field0 re-renders ONLY field0 ✅
// field1-field99 DO NOT re-render! 🎉
form.setValue("field0", "new value");
```

### 📦 Tree-Shakeable Architecture

```tsx
// Import only what you need
import { useForm } from "@lpm.dev/neo.react-forms";
import { email, minLength } from "@lpm.dev/neo.react-forms/validators";
import { zodForm } from "@lpm.dev/neo.react-forms/adapters";
```

### ✅ Comprehensive Validation

**36 built-in validators** + Zod integration:

```tsx
import {
  compose,
  required,
  email,
  minLength,
} from "@lpm.dev/neo.react-forms/validators";

const form = useForm({
  initialValues: { email: "", password: "" },
  validate: {
    email: compose(required(), email()),
    password: compose(required(), minLength(8)),
  },
});
```

### 🔌 Zod Integration

```tsx
import { zodForm } from "@lpm.dev/neo.react-forms/adapters";
import { z } from "zod";

const schema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
});

const form = zodForm({
  schema,
  onSubmit: async (values) => {
    // values is fully typed! ✅
    await api.signup(values);
  },
});
```

---

## Performance

### vs Formik & React Hook Form

| Metric             | neo.react-forms | Formik  | React Hook Form |
| ------------------ | --------------- | ------- | --------------- |
| **Bundle Size**    | **7.1 KB**      | 44.7 KB | 12.1 KB         |
| **Operations/sec** | **366,000+**    | ~30,000 | ~100,000        |
| **Re-renders**     | **1**           | 30+     | 1-2             |

**Results**:

- **96% smaller** than Formik
- **83% smaller** than React Hook Form
- **27-115% faster** for large forms

See [BENCHMARK-RESULTS.md](./BENCHMARK-RESULTS.md) for detailed metrics.

---

## License

MIT