Express-input-validation NPM

express-input-validation

npm version

An express.js middleware for input validation.

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Securing your APIs by validating the inputs.

express-input-validation is simple yet powerful node module that makes your API robust and discard any request with invalid input.

Installation
Features
Examples
Datatype-check
RoadMap
Next-Release
License

Installation

npm install express-input-validation

yarn add express-input-validation

Features

you can ask express-input-validation to get value from any of these(following list) using from key in rules array,

Header (header)
Query (query)
Body (body)
Params (param)

and can pass any custom validation function using validation_function in the rules array. Also you can pass a message in rules for particular rule or it'll be default send a invalid ${key_name} as message.

Example

Following are the example for validating using express-input-validation, here I have included all four type of inputs that most commonly an API can have:

    {
        "from": "query",
        "key": "emailId",
        validation_function: value => value.indexOf("@") > -1,
        "datatype": "number",
        "is_optional": true
    }

In rules array the above one can be one of the objects, here I've showed a custom validation_function without message, this ll return Invalid emailId incase the email id is not found or if it doesn't have an @ in the value string.

Now new rule can be defined as is_optional, where if its declared as optional, only if the field value found then it'll be validated otherwise it'll be ignored.

Datatype-check (optional)

In the rule you can also specify a datatype in datatype key to check for specific datatype of the value. datatypes can be checked below.

Datatype	Description	Alternative key
`number`	checks if its a valid number	`num`, `int`, `integer`
`string`	checks if typeof is string and first character is not a numeric	`str`
`float`	checks if its a number and has a decimal value	-
`object`	checks if a object	`obj`
`alphanumeric`	checks if value has atleast one character and number	-
`only-alpha`	checks if value has only alphabets	-

Note

key, from are required keys in object in all of the rule you define.
a rule without a validation_function is considered to be only required field, i.e., express-input-validation only checks if there is a field in specified from key in the object.
Datatype is still experimential.