@kitmi/validators

Dynamic Validator

@kitmi/validators is a comprehensive validation library designed to validate objects using a declarative syntax known as Js Type Modifiers Syntax (JTMS). It allows for dynamic validation strategies by using various types of modifiers that can be combined to form complex validation rules.

Installation

To install @kitmi/validators, please use one of the following package managers:

Using Bun:

bun install @kitmi/validators

Using npm:

npm install @kitmi/validators

Modifier Syntax

Modifiers in JTMS can be expressed in different formats, depending on whether they require arguments:

Standalone Modifiers: These are simply strings that consist of a modifier prefix followed by the modifier's name.
Modifiers with Arguments: These can be expressed either as objects or arrays:
- Object Style:
  - name: Modifier name (e.g., ~mobile)
  - options: Arguments for the modifier (e.g., { locale: 'en-US' })
- Array Style:
  - Index 0: Modifier
  - Index 1: Modifier options argument

Types of Modifiers

Modifiers are categorized based on their prefix:

Validator (~): Validates the value.
Processor (>): Transforms the value.
Activator (=): Provides a default value if the current value is null.

Modifier Handlers

Each type of modifier utilizes a different handler function with a specific signature:

Validator Handler: (value, options, meta, context) => [true/false, null/failed reason]
- A validator that returns false will halt the modifier pipeline and raise a ValidationError.
Processor Handler: (value, options, meta, context) => transformedValue
Activator Handler: (options, meta, context) => defaultValue
- An activator is invoked only if the current value is null.

Sample Usage

Here is an example demonstrating how to use @kitmi/validators:

import validator from '@kitmi/validators';

const result = validator.sanitize(obj, {
    type: 'object',
    schema: {
        key1: {
            type: 'integer',
            post: [
                ['~max', 30],
                ['~min', 10],
            ],
        },
        key2: {
            type: 'integer',
            post: [
                ['~max', 20],
                ['~min', 10],
            ],
        },
    },
    optional: true,
    post: [
        {
            name: '~jsv',
            options: {
                key1: {
                    $gt: '$$.key2',
                },
            },
        },
        [
            '>jsx',
            {
                $toArray: { name: '$$KEY', value: '$$CURRENT' },
            },
        ],
        '=default',
    ],
});

console.log(result);
// Output: [{ name: 'key1', value: 20 }, { name: 'key2', value: 15 }]

Synchronous and Asynchronous Usage

Synchronous Mode

import validator, { Types } from '@kitmi/validators';

validator.addValidator('isEmail', () => [true / false, 'reason if false']);
validator.addProcessor('escape', () => {});
validator.addActivator('randomFill', () => {});
const sanitizedValue = validator.sanitize(obj, schema);

Asynchronous Mode

import validator, { Types } from '@kitmi/validators/async';

validator.addValidator('isEmail', async () => [true / false, 'reason if false']);
validator.addProcessor('escape', async () => {});
validator.addActivator('randomFill', async () => {});
const sanitizedValue = await validator.sanitize_(obj, schema);

Including All Modifiers

For convenience, you can import versions of the library that include all built-in modifiers:

Synchronous: import validator from '@kitmi/validators/allSync';
Asynchronous: import validator from '@kitmi/validators/allAsync';

License

This project is licensed under the MIT License.

Written by GPT-4