@formajs/mold

> Data in Perfect Forma.

Mold is a powerful, chainable schema validation library tailored for the FormaJS ecosystem. It provides a fluent API to define, validate, and coerce data structures with ease.

Installation

``bash
npm install @formajs/mold
`

Basic Usage

`javascript
import { f } from '@formajs/mold';

const schema = f.object({
name: f.string().min(3).required(),
age: f.number().min(18).optional(),
email: f.string().email(),
tags: f.array(f.string()).min(1),
});

const result = await schema.validate({
name: 'John Doe',
age: 25,
email: 'john@example.com',
tags: ['developer', 'js'],
});

if (result.valid) {
console.log('Valid data:', result.value);
} else {
console.error('Validation errors:', result.errors);
}
`

API Reference

$3

- f.string(): Validates strings. Chain with .min(), .max(), .email(), .url(), .uuid(), etc.
- f.number(): Validates numbers. Chain with .min(), .max(), .int(), .positive(), etc.
- f.boolean(): Validates booleans.
- f.date(): Validates Date objects. Chain with .min(date), .max(date).
- f.file(): Validates File objects. Chain with .minSize(), .maxSize(), .type().

$3

- f.object(shape): Defines a structured object.
- .strip(): Remove unknown keys (default: passthrough).
- .strict(): Error on unknown keys.
- .passthrough(): Keep unknown keys.
- .pick(keys): Select specific keys.
- .omit(keys): Remove specific keys.
- .partial(): Make all fields optional.
- .required(): Make all fields required.
- .extend(shape): Add fields.
- f.record(valueSchema): Validates an object where all values match strict schema.
- f.map(keySchema, valueSchema): Validates a JavaScript Map.

$3

- f.array(itemSchema): Validates an array of items. Chain with .min(), .max().
- f.set(valueSchema): Validates a JavaScript Set.
- f.tuple([schema1, schema2]): Validates a fixed-length array with specific types.

$3

- f.literal(value): Matches an exact value.
- f.enum(values): Matches one of the provided values.
- f.union([schemaA, schemaB]) or f.or([A, B]): Matches any of the schemas.
- f.intersection(schemas) or f.and([A, B]): Matches all schemas.
- f.promise(valueSchema): Validates a Promise and its resolved value.
- f.function(): Validates a function.
- f.lazy(() => schema): For recursive schemas.

$3

All schemas support:
- .optional(): Marks the value as optional (allows undefined).
- .required(): Marks the value as required.
- .default(value): Sets a default value if undefined.
- .transform(fn): Transforms the value.
- .refine(fn, options): Custom validation logic.
- .catch(value): specific fallback value on error.
- .describe(text): Adds metadata description.

$3

Mold provides a coerce namespace to automatically convert types before validation:

`javascript
const schema = f.object({
id: f.coerce.number(), // "123" -> 123
active: f.coerce.boolean(), // "true" -> true
created: f.coerce.date(), // ISO string -> Date
});
``