light-paradate

Lightweight request params validator

Table of Contents

• Introduction
• Features
• Installation
• Usage
• License

Introduction

This library helps validate incoming request data by checking for:

• Presence (required fields)
• Minimum length of string fields
• Value inclusion in a predefined list
• Email format validation

Support

• TypeScript Support: Includes type definitions.
• CJM, ESM support: Supports both CommonJS and ES modules.

Features

• validField
• validEmail

Installation

npm install light-paradate

Or with Yarn:

yarn add light-paradate

Usage

validField

validField(reqOrFieldValues, fieldName, options)

Extracts a field from req.params, req.query, or req.body, then runs validations according to the provided options. You can either pass one of those field containers directly as the first argument, or a req object. In that case, params, query, and body will be searched for the passed fieldName.

example:

const uuid = validField(req, 'uuid', { minLength: 36 });
const parentId = validField(req.params, 'parent_id', { numericality: { onlyInteger: true, greaterThan: 0 } });
const id = validField(req, 'id', { match: /^[1-9]\d*$/ });
const orderBy = validField(req.query, 'orderBy', { includedIn: ['name', 'email', 'status'] });
const statuses = validField(req.query, 'statuses[]', { includedIn: ['invited', 'active'] });
const firstName = validField(req.body, 'firstName', { minLength: 5 });

Parameters

• reqOrFieldValues: A request-like object with params, query, and body, or a direct field container such as req.params, req.query, or req.body.
• fieldName: The field name to retrieve from the request object or direct field container.
• options: An optional object containing validation requirements. Possible values for the options argument include:
  • optional: boolean - Allows the field to be omitted even when other validators such as minLength are configured.
  • required: boolean - Indicates whether the field must have a non-empty value.
  • minLength: number - Specifies the minimum length the field value should have.
  • maxLength: number - Specifies the maximum length the field value can have.
  • match: RegExp - Validates the field value against a regular expression.
  • numericality: boolean | object - Converts the field to a number and validates numeric constraints. Supported object keys: onlyInteger, greaterThan, greaterThanOrEqualTo, lessThan, lessThanOrEqualTo.
  • includedIn: string[] - An array of valid strings that the field value must match to pass validation.

Return Value

• If valid, returns the string, number, string array, or number array (in case of fields that use [] notation).
• Returns undefined if the field is not required and not present, or if optional: true is set and the field is omitted.
• Throws an error if validation fails.

Behavior

• Check presence: If options.required is set or if options.minLength is defined, the field must be present unless optional: true is set.

• Check length: If options.minLength is set, throws an error if the field’s value is shorter than the specified length.

• Check pattern: If options.match is defined, throws an error if the field’s value does not match the provided regular expression.

• Check numericality: If options.numericality is defined, converts the field to a number and throws an error if it is not numeric or does not satisfy the configured numeric constraints.

• Check inclusion: If options.includedIn is defined, throws an error if the field’s value (or values) are not in the specified list.

  Array fields: If your field name ends with [] (e.g., statuses[]), the utility will treat the field as an Array. If there is only one value, it will be returned in a single-element array.

validEmail

validEmail(req, options)

Extracts and validates the "email" field from req.query or req.body, ensuring it is both present and syntactically valid.

example:

const email = validEmail(req);
const alternateEmail = validEmail(req, { optional: true });

Parameters

• req: A request-like object with query and body.
• options: Optional configuration.
  • optional: boolean - Allows email to be omitted. If present, it is still validated.

Return Value

• Returns a valid email string if validation passes.
• Returns undefined if optional: true is set and the email is missing.
• Throws an error if the email is invalid, or if it is missing without optional: true.

Behavior

• Checks presence: Throws an error emailRequired if the field email is not found in either req.query or req.body, unless optional: true is set.
• Checks format: Uses the email-validator package under the hood to ensure the format is correct. If invalid, throws an error emailInvalid.

License

This project is licensed under the MIT License.

Package URL

https://www.npmjs.com/package/light-paradate

Code repository

https://bitbucket.org/endeavia/light-paradate/src/master/

Author

Tamás Kamarás