validatable/README.md

A library for synchronous and asynchronous input validation.

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# validatable.js

> A library for synchronous and asynchronous input validation.

This is a light weight open source package for use on **server** or in **browser** (using module bundler). The source code is available on [GitHub](https://github.com/xpepermint/validatablejs) where you can also find our [issue tracker](https://github.com/xpepermint/validatablejs/issues).

## Related Projects

* [RawModel.js](https://github.com/xpepermint/rawmodeljs): Strongly-typed JavaScript object with support for validation and error handling.
* [Typeable.js](https://github.com/xpepermint/typeablejs): A library for checking and casting types.
* [Handleable.js](https://github.com/xpepermint/handleablejs): A library for synchronous and asynchronous error handling.

## Install

Run the command below to install the package.

```
$ npm install --save validatable
```

This package uses promises thus you need to use [Promise polyfill](https://github.com/taylorhakes/promise-polyfill) when promises are not supported.

## Example

```js
import {Validator} from 'validatable';

let v = new Validator();

let e = await v.validate(
  '', // value to validate
  [ // list of validations
    {
      validator: 'presence', // validator name
      message: '%{foo} must be present', // validator options
      foo: 'bar' // a custom variable for the message
    }
  ]
); // -> list of errors
```

See the `./tests` folder for details.

## API

**Validator({failFast, validators, context})**

> A core validation class.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| failFast | Boolean | No | false | When set to `true`, the validation stops after the first validation error.
| validators | Object | No | built-in validators | Object with custom validators (this variable is merged with built-in validators thus you can override a validator key if you need to).
| context | Object | No | null | A context reference which is applied to each validator method.

```js
import {Validator} from 'validatable';

let v = new Validator({
  failFast: true,
  validators: {
    async coolness ({value, recipe}}) { return value === 'cool' } // custom validator
  },
  context: null
});
```

**Validator.prototype.validate(value, recipes)**: Promise(Object[])

> Validates a value against the provided options.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| value | Any | Yes | - | A value to validate.
| recipes | Array | Yes | [] | A configuration object describing validators.

```js
let value = 'John Smith';
let recipe = {
  validator: 'presence', // [required] validator name
  message: '%{foo} must be present', // [optional] validation error message (note that you can insert related recipe values by using the %{key} syntax)
  code: 422, // [optional] validation error code
  condition: () => true, // [optional] a condition which switches the validation on/off
  foo: 'bar' // [optional] a custom variable
};
let recipes = [recipe];
await v.validate(value, recipes);
```

### Built-in Validators

**absence**

> Validates that the specified field is blank.

**arrayExclusion**

> Validates that the specified field is not in an array of values.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| values | Array | Yes | - | Array of restricted values.

**arrayInclusion**

> Validates that the specified field is in an array of values.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| values | Array | Yes | - | Array of allowed values.

**arrayLength**

> Validates the size of an array.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| min | Number | No | - | Allowed minimum items count.
| minOrEqual | Number | No | - | Allowed minimum items count (allowing equal).
| max | Number | No | - | Allowed maximum items count.
| maxOrEqual | Number | No | - | Allowed maximum items count (allowing equal).

**block**

> Validates the specified field against the provided block function. If the function returns true then the field is treated as valid.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| block | Function,Promise | Yes | - | Synchronous or asynchronous function (e.g. `async () => true`)

```js
let recipe = {
  validator: 'block',
  message: 'must be present',
  async block (value, recipe) { return true }
};
```

**BSONObjectID**

> Validates that the specified field is a valid hex-encoded representation of a [MongoDB ObjectID](http://docs.mongodb.org/manual/reference/object-id/).

**numberSize**

> Validates the size of a number.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| min | Number | No | - | Allowed minimum value.
| minOrEqual | Number | No | - | Allowed minimum value (allowing equal).
| max | Number | No | - | Allowed maximum value.
| maxOrEqual | Number | No | - | Allowed maximum value (allowing equal).

**presence**

> Validates that the specified field is not blank.

**stringBase64**

> Validates that the specified field is base64 encoded string.

**stringDate**

> Validates that the specified field is a date string.

| Option | Type | Required | Default | Description
|--------|------|----------|----------|-----------
| iso | Boolean | No | false | When `true` only ISO-8601 date format is accepted.

**stringEmail**

> Validates that the specified field is an email.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| allowDisplayName | Boolean | No | false | When set to true, the validator will also match `name <address>`.
| allowUtf8LocalPart | Boolean | No | false | When set to false, the validator will not allow any non-English UTF8 character in email address' local part.
| requireTld | Boolean | No | true | When set to false, email addresses without having TLD in their domain will also be matched.

**stringETHAddress**

> Checks if the string represents an ethereum address.

**stringExclusion**

> Checks if the string does not contain the seed.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| seed | String | Yes | - | The seed which should exist in the string.

**stringFQDN**

> Validates that the specified field is a fully qualified domain name (e.g. domain.com).

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| requireTld | Boolean | No | true | Require top-level domain name.
| allowUnderscores | Boolean | No | false | Allow string to include underscores.
| allowTrailingDot | Boolean | No | false | Allow string to include a trailing dot.

**stringHexColor**

> Validates that the specified field is a hexadecimal color string.

**stringHexadecimal**

> Validates that the specified field is a hexadecimal number.

**stringInclusion**

> Checks if the string contains the seed.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| seed | String | Yes | - | The seed which should exist in the string.

**stringJSON**

> Validates that the specified field is a stringified JSON string.

**stringLength**

> Validates the length of the specified field.

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| bytes | Boolean | No | false | When `true` the number of bytes is returned.
| min | Number | No | - | Allowed minimum number of characters.
| minOrEqual | Number | No | - | Allowed minimum value number of characters (allowing equal).
| max | Number | No | - | Allowed maximum number of characters.
| maxOrEqual | Number | No | - | Allowed maximum number of characters (allowing equal).

**stringLowercase**

> Validates that the specified field is lowercase.

**stringMatch**

> Validates that the specified field matches the pattern.

| Key | Type | Required | Default | Description
|-----|------|----------|---------|------------
| regexp | RegExp | Yes | - | Regular expression pattern.

**stringUppercase**

> Validates that the specified field is uppercase.

**stringUUID**

> Validates that the specified field is a [UUID](https://en.wikipedia.org/wiki/Universally_unique_identifier).

| Option | Type | Required | Default | Description
|--------|------|----------|---------|------------
| version | Integer | No | - | UUID version (1, 2, 3, 4 or 5).

## License (MIT)

```
Copyright (c) 2016 Kristijan Sedlak <xpepermint@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
```