EXPRESS-KEY-VALIDATOR

A simple body-key-validator for your express-app. Using schemas to define the expected-keys and their expected type.

Installation

Installation is done using npm install command: > npm install express-key-validator

Usage

> const express = require('express')
> const Validator = require('express-key-validator')
>
> const app = express()
> app.use(express.json())
> app.use(express.urlencoded({ extended:  true}))
>
> app.use(Validator.validateKeys)
>
> 
> const Connect = Validator.Route.Connect
>
> const UserSchema = new Validator().Schema().Create({
>    firstname: new Validator().string().min(3),
>    username: new Validator().string().required(),
>    password: new Validator().string().min(15).required(),
>    age: new Validator().integer().positive(),
> })
>
> Connect("/user", UserSchema)
>
> app.post("/user",(req, res) => {
>    ...
>    res.send("success")
> })

Validation options

> string() - Checks if the value is of type 'string'
> integer() - Checks if the value is of type 'number'
> min(3) - Defines the minimum length of the value
> max(10) - Defines the maximum length of the value
> email() - Checks if the value is a valid email-address
> email({regex: *custom regex*}) - Makes it possible to use your own regex for email validation instead of using the default one
> enum([]) - Defines a set of allowed values
> lowercase() - Transform the value to lowercase
> uppercase() - Transform the value to uppercase
> trim() - Trims the value
> default("") - If the received value is undefined, it will use the value passed to the default function. 
> positive() - Checks if the value is a positive number
> negative() - Checks if the value is negative number
> required() - Defines that the param is required and will throw error if the param is not found
> regex( *regex* ) - Checks if the value matches the passed regex-expression
> custom(*callback*) - Allows you to create a custom validation

Example

> const UserSchema = new Validator().Schema().Create({
>    firstname: new Validator().string().min(3),
>    email: new Validator().string().email()
> })

.custom()

const userSchema = new Validator().Schema().Create({
>   customCallback: new Validator().custom(v => {
      if(typeof v === 'string') return true;
      return false;
    })
})

The callback has to return either true or false.

• True indicating that the value is valid.
• False indicating that the value is not valid.

Options

Alternative options that can be used.

StrictMode

const Validator = require('express-key-validator')
new Validator().useStrictMode(true)

Setting strictMode to true means that every single param defined in the schema is automatically required. There is no need to use required() when using strictMode.

SecureMode

const Validator = require('express-key-validator')
new Validator().useSecureMode(true)

Setting secureMode to true means that it will ONLY allow params defined in the schema.

Response types

Missing params

{
  "type": "missing_param(s)",
  "success": false,
  "missing_params": [
    "firstname"
   ]
}

Invalid params

{
  "type": "invalid_param(s)",
  "success": false,
  "invalid_params": [
    "firstname"
   ]
}

Unknown params NOTE: This only applies when secureMode is set to true.

{
  "type": "unknown_param(s)",
  "success": false,
  "unknown_params": [
    "asdasd"
   ]
}

Response Options:

const Response = Validator.Response
Response.Options({detailed: true})

Response output:

{
   "type": "invalid_param(s)",
   "success": false,
   "invalid_params": [
     {
       "firstname": {
         "expected_type(s)": [
            "String"
          ]
        }
      },
   ]
}

Custom response templates

This is an option that allows you to use your own custom template for the different responses.

How to enable custom templates:

const Validator = require('express-key-validator')
new Validator().useCustomTemplate()

Create a file named > validator.config.yml, In this file you can define the templates used for the different responses.

You can name the config file whatever you want. But the file has to be a yaml-file.

If you use something other than 'validator.config.yml'

How to use a config-file named something else:

const Validator = require('express-key-validator')
new Validator().useCustomTemplate('customName.CanBeAnything.yml')

Valid templates are: missing_params, invalid_params and unknown_params.

Inside validator.config.yml

missing_params:
    template: {
        success: false,
        missingPARAMS: $params$,
        CUSTOM: 'CUSTOM'
    }

Output:

{
    success: false,
    missingPARAMS: ["firstname"],
    CUSTOM: 'CUSTOM'
}

• $params$ defines where the actual params will go in your template. This is totally optional, you can create a template without $params$.

Contribution

Pull requests are welcome. For any considerable changes, please open an issue first to discuss what you would like to change. NOTE: This is still in BETA so please let me know if there are any features that you think can be improved or added.