phantasy-validation/lib/main.js.flow

Type-safe validation

// @flow
import type { Node } from 'validated/schema';
import * as t from 'validated/schema';
import { Result } from 'phantasy';
import { validate as jsonValidate } from 'validated/json5';
import { validate as valValidate } from 'validated/object';

export type RuntimeType<T> = Node<T>

export type ValidationError = {
	message: string,
	validated: mixed,
	originalError: Error
}

/**
 * `validationError :: Error -> mixed -> ValidationError`
 */
export function validationError(err: Error, validated: mixed): ValidationError {
	return {
		message: err.message,
		validated,
		originalError: err
	};
}

/**
 * `validateJson :: Node t -> string -> Result t ValidationError`
 */
export function validateJson<T>(schema: Node<T>, json: string): Result<T, ValidationError> {
	return Result.fromThrowable(() => jsonValidate(schema, json))
		.handleError(err => Result.Err(validationError(err, json)));
}

/**
 * `validateValue :: Node t -> mixed -> Result t ValidationError`
 */
export function validateValue<T>(schema: Node<T>, value: mixed): Result<T, ValidationError> {
	return Result.fromThrowable(() => valValidate(schema, value))
		.handleError(err => Result.Err(validationError(err, value)));
}

// run-time types
export const any = t.any;
export const bool = t.boolean;
export const num = t.number;
export const str = t.string;
export const enumeration = t.enumeration;
export const array = t.arrayOf;
export const obj = t.object;
export const partial = t.partialObject;
export const maybe = t.maybe;
export const union = t.oneOf;
export const ref = t.ref;