Validation Rules

A Validation rule is a syntax that carries information about the validators that should be used to validate any input and the order at which rules should be applied.

Validation rules can be written in a number of ways:

// object
{ required: true, minLength: 2 };

// string (short-hand)
"required|minLength:2";

// array of both
[ "required", { minLength: 2 } ];

Note: All validation rules are converted/parsed to objects before being applied. All rules type used in the example above will be converted to:

{ required: true, minLength: 2 }

This means that validation rules already defined as objects will be slightly faster than the others.

Types

Object

The object syntax is the default way of defining validation rules. where the object keys are the validators and the values are the validation options.

{required: true, minLength: 2}
// `required` is a validator, `true` is the validation option.
// `minLength` is a validator, `2` is the validation option.

String (short-hand)

The string syntax is a shorthand for writing validation rules where:

Rules are separated by |
: (if present) is used to separate the validator and its validation option.
It sets validation option to true by default and false if the ! sign is used.
Number options are converted to numeric values.

For example:

"required"; // => { required: true }

"!required"; // => { required: false }

"minLength:2|maxLength:10"; // => { minLength: 2, maxLength: 10 }

"exact:hello"; // => { exact: "hello" }

Array

The array syntax is a shorthand used for mixing string and object validation rules.

For example:

["required", { minLength: 2 }];
// => { required: true, minLength: 2 }

// prettier-ignore
// Or when using super rules that begins with `$`
[
    "required|minLength:2",
    {
      $name: "Custom Name",
      $error: "A custom error message"
    }
];

// wii be converted to:
{
    required: true,
    minLength: 2,
    $name: "Custom Name",
    $error: "A custom error message"
};

Super Rules

Super rules are rules that starts with $.

$name

if the $name key is present, it will be used as the name of the field.

Abolish.attempt(18, ["typeof:number|max:5"]);
// Error: Variable is too big. (Max. 5)

Abolish.attempt(18, ["typeof:number|max:5", { $name: "Age" }]);
// Error: Age is too big. (Max. 5)

$error

if the $error key is present, it will be used as the error message.

// prettier-ignore
Abolish.attempt(18, [
    "typeof:number|max:5", 
    { $error: "You are just too old for this." }
]);
// Error: You are just too old for this.

$errors

Unlike $error, the $errors key gives you the ability to define/override errors for each validator.

Note: The $errors key overrides the $error key.

Abolish.attempt("not a number", ["typeof:number|max:5"]);
// Error: Variable is not typeof number

// Define custom error message for `typeof`
Abolish.attempt("not a number", [
    "typeof:number|max:5",
    { $errors: { typeof: "Please enter a number" } }
]);
// Error: Please enter a number.

$skip

The $skip rule is used to skip validation for a specific field or variable. it accepts a boolean or a function(value?) => boolean. if true, the field will be skipped.

let skipMobile = true;

Abolish.validate(data, {
    mobile: {
        $skip: skipMobile,
        someMobileValidator: true
    },
    username: "required"
});

// mobile will not be validated because `$skip` is true
// `$skip` can also accept a function that returns a boolean
// The current value its validating will be passed to that function also

skipMobile = (mobile) => {
    // skip if mobile is empty else run validation.
    return !mobile.length;
};

// mobile will be validated because :skip function returned false

$skip also works when using attempt, check or test validation methods.

// Attempt
const comment = Abolish.attempt(rawComment, [
    // skip validation if admin
    { $skip: authUser === "admin" },
    "checkForSpam"
]);
// Validation will be skipped if `authUser` is `admin`
// post will be the same as someBlogPost if not modified by any validator.

$inline

The $inline rule provides a way to validate without pre-defining a validator.

// Syntax
Abolish.attempt(value, { $inline: (value, { modifier, error }) => boolean | error });

// Example
Abolish.attempt("mail.example.com", {
    $inline: (value, { modifier, error }) => {
        // validate email address
        if (!value.includes("@")) {
            throw new Error("Invalid email address");
            // OR
            return error("Invalid email address");
        }

        // set to lowercase
        modifier.setThis(value.toLowerCase());
    }
});
// Error: Invalid email address

Helpers

These are syntactic sugar functions to make declaring rules easier.

Rule()

The Rule function is used parse/combine rules to an `object

const {Rule} = require("abolish"); // OR import {Rule} from "abolish";

const isEmail = Rule("typeof:string|email");
// will be converted to:
{ typeof: "string", email: true }

// Or with custom name and error message
const isEmail = Rule([
    "typeof:string|email",
    { $name: "Email address", $error: "Please enter a valid email address"}
]);

// will be converted to:
{
    typeof: "string",
    email: true,
    $name: "Email address",
    $error: "Please enter a valid email address"
};

Schema()

The Schema function is used to parse key:rule pairs.

const {Schema} = require("abolish"); // OR import {Schema} from "abolish";

const rules = Schema({
    name: "required|string",
    age: "required|typeof:number|min:18|max:100"
});

// will be converted to:
{
  name: { required: true, string: true },
  age: { required: true, typeof: 'number', min: 18, max: 100 }
}

$inline()

The $inline is a helper function to create an $inline validator rule.

const { $inline } = require("abolish/src/helpers");
// OR import {$inline} from "abolish/src/helpers";

$inline((value, { modifier, error }) => true);
// is the same as: (But Typed)
{
    $inline: (value, { modifier, error }) => true;
}

As seen in the example above, the $inline function accepts a validator function as its first argument.

It can also accept an error message as its second argument. Note that this error message is used as $error property.

Using the same example used in the $inline validator:

// It will be
Abolish.attempt(
    "mail.example.com",
    $inline((value, { modifier, error }) => {
        // validate email address
        if (!value.includes("@")) {
            throw new Error("Invalid email address");
            // OR
            return error("Invalid email address");
        }

        // set to lowercase
        modifier.setThis(value.toLowerCase());
    })
);

skipIfUndefined()

The skipIfUndefined is a helper function to create a $skip if value===undefined validator rule.

const { skipIfUndefined } = require("abolish/src/helpers");
// OR import {skipIfUndefined} from "abolish/src/helpers";

skipIfUndefined("number|min:18");
// will be converted to:
{
    $skip: (value) => value === undefined,
    number: true,
    min: 18
}

skipIfNotDefined()

The skipIfNotDefined is a helper function to create a $skip if value===undefined | null validator rule.

const { skipIfNotDefined } = require("abolish/src/helpers");
// OR import {skipIfNotDefined} from "abolish/src/helpers";

skipIfNotDefined("number|min:18");
// will be converted to:
{
    $skip: (value) => value === undefined || value === null,
    number: true,
    min: 18
}

# Validation Rules

# Types

# Object

# String (short-hand)

# Array

# Super Rules

# $name

# $error

# $errors

# $skip

# $inline

# Helpers

# Rule()

# Schema()

# $inline()

# skipIfUndefined()

# skipIfNotDefined()