Contents

• About
• Features
• Installation
• Documentation
  • Tree
  • Import
  • Constructors
  • Methods
  • Patterns
  • Types
• Links
  • Discord
  • Telegram
  • Twitter
  • GitHub
• License

About

Portable and simple schemas for property validation.

Features

• Easy and understandable schemas
• Contains ready regex patterns
• Portable schemas as a JSON file
• Schemas can be declared for TypeScript
• Schemas can be converted to JSON Schema. JSON Schema is OpenAPI compatible
• Error messages are ready to be understood but can be edited if desired

Installation

You can install it as follows.

# NPM
npm add yuppi

# PNPM
pnpm add yuppi

# Yarn
yarn add yuppi

# Bun
bun add yuppi

# Deno
deno add yuppi

Documentation

Tree

Briefly as follows.

yuppi
│
├── new Yuppi(options?)
│   │
│   └── schema(schema)
│       │
│       ├── validate(data)
│       ├── declare(name)
│       └── toJSONSchema()
│
├── Patterns
│   │
│   ├── Domain
│   ├── Email
│   ├── HTTP
│   ├── PhoneNumber
│   ├── URI
│   └── Username
│
├── type InferSchema
├── type JSONSchema
├── type Schema
├── ValidationError
└── type YuppiOptions

Import

Briefly as follows.

import { Yuppi, Patterns } from 'yuppi';

Constructors

new Yuppi(options?)

Yuppi schema builder.

Parameter	Type	Default	Description
options?	YuppiOptions	YuppiOptionsDefault	Constructor's options.

Example:

const yuppi = new Yuppi();

Methods

Yuppi.schema(schema).validate(data)

Validate the data with your Yuppi schema.

Parameter	Type	Default	Description
schema	Schema		Yuppi schema.
data	Unknown		data to be validate.

returns InferSchema<Schema>

Example:

const schema = yuppi.schema({
  display_name: { type: 'string', max: 32 },
  username: { type: 'string', pattern: Patterns.Username, min: 3, max: 16 },
  email: { type: 'string', pattern: Patterns.Email, lowercase: true },
  permissions: [
    { type: 'string', enum: ['*'] },
    { type: 'array', items: { type: 'string', enum: ['read', 'write'] } }
  ]
});

const data = {
  display_name: 'Fırat',
  username: 'fir4tozden',
  email: 'fir4tozden@gmail.com',
  permissions: '*'
};

let fields;

try {
  fields = schema.validate(data);
  /*
    {
      display_name: "Fırat",
      username: "fir4tozden",
      email: "fir4tozden@gmail.com",
      permissions: "*"
    }
  */
} catch (error) {
  if (error instanceof ValidationError) console.log(errors[0]);
  /*
    {
      message: "Field email must match the required pattern",
      parts: {
        path: "email"
      },
      code: "field-email-must-match-the-required-pattern",
    }
  */
}

console.log(fields.display_name); // "Fırat"

Yuppi.schema(schema).declare(name)

Declare your Yuppi schema for TypeScript.

Parameter	Type	Default	Description
schema	Schema		Yuppi schema.
name	String		Declaration name.

returns Promise<Void>

Example:

import type { User } from './generated/yuppi/types/User';

await schema.declare('User');

let fields;

try {
  fields = schema.validate(data) as User;
  /*
    interface User {
      display_name: string;
      username: string;
      email: string;
      permissions: "*" | ("read" | "write")[];
    }
  */
} catch (error) {
  // ...
}

Yuppi.schema(schema).toJSONSchema()

Convert your Yuppi schema into JSON Schema.

Parameter	Type	Default	Description
schema	Schema		Yuppi schema.

returns JSONSchema

Example:

schema.toJSONSchema();
/*
  {
    additionalProperties: false,
    type: 'object',
    required: ['display_name', 'username', 'email', 'permissions'],
    properties: {
      display_name: {
        maxLength: 32,
        trim: true,
        type: 'string'
      },
      username: {
        minLength: 3,
        maxLength: 16,
        pattern: '^(?=.*[a-zA-Z])[a-zA-Z0-9][a-zA-Z0-9_]*$',
        trim: true,
        type: 'string'
      },
      email: {
        pattern: '^[a-zA-Z0-9._-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,}$',
        trim: true,
        lowercase: true,
        uppercase: true,
        type: 'string'
      },
      permissions: {
        anyOf: [
          { enum: ['*'], trim: true, type: 'string' },
          { type: 'array', items: { enum: ['read', 'write'], trim: true, type: 'string' } }
        ]
      }
    }
  }
*/

Patterns

Pattern	Description	Examples
Domain	Domains.	"google.com" ✅ "www.google.com" ✅ "https://google.com" ❌
Email	Emails.	"fir4tozden@gmail.com" ✅ "fir4tozden+2@gmail.com" ❌
HTTP	HTTP only links.	"https://google.com" ✅ "http://google.com" ✅ "google.com" ❌
PhoneNumber	Country code and phone number.	"0090-555555555" ✅ "90-5555555555" ❌
URI	Protocol free links.	"mongodb://mongodb.net" ✅ "https://google.com" ✅ "google.com" ❌
Username	Usernames like Twitter.	"fir4tozden" ✅ "Fir4tozden" ✅ "fir4t ozden" ❌

Types

Type
InferSchema
JSONSchema
Schema
ValidationError
YuppiOptions

Links

• Discord
• Telegram
• Twitter
• GitHub

License

MIT License

Copyright (c) 2025 Keift

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.