AWS Mock Data

AWSome mock data for Node.js based AWS services

Overview

AWS Mock Data is a Node.js library that provides realistic mock data for AWS services. It’s designed to streamline the development and testing of AWS-based applications by generating valid JWT tokens, JWKs, and other mock service data.

✅ Features

• 🔐 Generate valid Cognito JWT ID and access tokens
• 🔑 Create JWKS (JSON Web Key Sets) for token verification
• 📘 Written in TypeScript with full type safety
• 🧪 Ideal for unit/integration tests and local development
• 🚀 Zero-config setup – ready out of the box

Installation

Using npm:

npm install --save-dev aws-mock-data

Or with Yarn:

yarn add --dev aws-mock-data

Quick Start

import { awsServices, utils, types } from "aws-mock-data";

const keyPair = utils.getAsymmetricKeys();

const user: types.User = {
	emailId: "user@example.com",
	givenName: "John",
	familyName: "Doe",
	emailVerified: true
};

// Create tokens with custom configuration
const tokens = awsServices.cognito.getCognitoTokens({
	asymmetricKeys: keyPair,
	user,
	cognito: {
		groups: ["admin", "users"],
		roles: ["arn:aws:iam::123456789012:role/AdminRole"]
	},
	userPool: {
		id: "us-east-1_ABC123",
		region: "us-east-1"
	},
	jwtConfig: {
		minutesToExpiry: 60,
		authTimeInEpoch: Math.floor(Date.now() / 1000)
	}
});

API Reference

awsServices.cognito.getCognitoTokens(options)

Generates mock Cognito ID and Access tokens.

Parameters:

• asymmetricKeys — Key pair used for signing JWTs
• user — User information (required)
• cognito — Optional Cognito-specific data (e.g., groups, roles)
• userPool — Optional user pool settings
• jwtConfig — Optional token timing configuration

Returns: CognitoTokens — { id_token, access_token }

awsServices.userPool.getUserPoolJwks(options)

Generates a JWKS (JSON Web Key Set) for token validation.

Parameters:

• asymmetricKeys — RSA key pair for JWK generation

Returns: Single JWK object or null on failure

utils.getAsymmetricKeys(options?)

Generates an RSA key pair for signing and verification.

Options:

• keyLength — Bit size of the key (default: 2048)

Returns: AsymmetricKeys — Key ID, PEM strings, and JWK object

Advanced Examples

Token Verification with jsonwebtoken

import jwt from "jsonwebtoken";

const keyPair = utils.getAsymmetricKeys();
const tokens = awsServices.cognito.getCognitoTokens({
	asymmetricKeys: keyPair,
	user: { emailId: "test@example.com" }
});

// Verify the token
const decoded = jwt.verify(tokens.id_token, keyPair.pem.publicKey);
console.log(decoded);

Simulated JWKS Endpoint

const keyPair = utils.getAsymmetricKeys();
const jwks = awsServices.userPool.getUserPoolJwks({
	asymmetricKeys: keyPair
});

// Mock JWKS endpoint response
const jwksResponse = {
	keys: [jwks]
};

Best Practices

🔐 Security

• Not for production use — testing only
• Keep private keys out of source control
• Generate new keys per test suite when possible

⚙️ Performance

• Reuse key pairs to speed up tests
• Cache tokens until expiry
• Avoid over-configuration – use sensible defaults

Contributing

We welcome contributions! Please see CONTRIBUTING.md for:

• Project setup
• Running tests and linters
• PR guidelines and code style

Changelog

See CHANGELOG.md for a detailed history of changes and releases.

License

MIT © Hanut Arora