https://github.com/michalzalecki/policeman

Lightweight yet powerful schema validator
https://github.com/michalzalecki/policeman

Last synced: 28 days ago
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Lightweight yet powerful schema validator

• Host: GitHub
• URL: https://github.com/michalzalecki/policeman
• Owner: MichalZalecki
• License: mit
• Created: 2016-08-14T06:50:22.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-10-31T12:54:12.000Z (about 8 years ago)
• Last Synced: 2024-11-24T17:15:43.115Z (about 2 months ago)
• Language: TypeScript
• Size: 215 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# policeman

[![CircleCI](https://circleci.com/gh/MichalZalecki/policeman.svg?style=svg)](https://circleci.com/gh/MichalZalecki/policeman)

Lightweight yet powerful schema validator

***

[API Docs](https://michalzalecki.github.io/policeman) | [Examples](#examples)

***

* Validate objects based on provided schema

* Inspired by [mappet](https://github.com/MichalZalecki/mappet/)

## Installation ([npm](https://www.npmjs.com/package/policeman))

```

npm i -S policeman

```

## Examples

```js

import policeman, { isRequired, isEmail, isMatching, combineValidators } from "policeman";

// setup entry validators

const requiredValidator = isRequired(() => "is required");

const emailValidator = isEmail(() => "is invalid email");

const phoneNumberValidator = isMatching(/\d{3}-?\d{3}-?\d{3}/, () => "is invalid phone");

// setup entry filter predicates

const isGift = (value, source) => source.gift === true;

// define schema

const schema = [

  // 1. array of validators - multiple errors

  // 2. combine validators - first of many errors

  // 3. single validator - single error

  // 4. skip validation based on filter predicate

  ["email", "email", [requiredValidator, emailValidator]], // #1

  ["phone", "phone", combineValidators(requiredValidator, phoneNumberValidator)], // #2

  ["name", "name", requiredValidator], // #3

  ["giftCode", "giftCode", requiredValidator, isGift], // #4

  // [dest, source, Validator, Filter]

];

// create validator

const validator = policeman(schema);

// validate

validator({ gift: false, email: "invalid@example", phone: "777-666-55" });

// {

//   valid: false,

//   errors: {

//     email: ["is invalid email"],

//     phone: "is invalid phone",

//     name: "is required"

//   }

// }

```

See [tests](src/test/policeman.test.ts) for more examples.

## Built-in validators

All built-in validators are [curried](https://lodash.com/docs#curry).

### `isRequired(() => message, value)`

Validates presence. Fails on `null`, empty string or `undefined`.

### `isMinLength(min, () => message, value)`

Passed `value` must be a string longer or with length equal to `min`.

### `isMaxLength(max, () => message, value)`

Passed `value` must be a string shorther or with length equal to `max`.

### `isEqualLength(equal, () => message, value)`

Passed `value` must be a string shorther or with length equal to `max`.

### `isEmail(() => message, value)`

Passed `value` must be a valid email. It's a simple check, if you need more complex solution use

`isMatching` or `isPassing`.

### `isMatching(regexp, () => message, value)`

Passed `value` must pass `regexp`.

### `isPassing(predicate, () => message, value)`

Passed `predicate` answers on "Is `value` valid?". When `predicate` returns `true` validator passes,

when `predicate` returns `false` error message is returned.

It makes `policeman` compatible with all available validators i.e. [validator](https://www.npmjs.com/package/validator).

```js

import validator from "validator";

import { isPassing } from "policeman";

const creditCardValidator = isPassing(validator.isCreditCard, () => "is invalid credit card");

const uuid4Validator = isPassing(value => validator.isUUID(value, 4), () => "is invalid UUID v4");

const ftpValidator = isPassing(value => validator.isURL(value, { protocols: ["ftp"] }, () => "is invalid FTP address");

```

See [tests](src/test/validators.test.ts) for more examples.