Challenge: Blog App with Validation & Tests

Overview

Your challenge is to enhance the blog application from Module 2 by adding validation rules and comprehensive tests to ensure data integrity and verify functionality.

Key Learning Goals

Through this challenge, you’ll gain practical experience with:

  • Implementing various types of validation rules
  • Writing comprehensive tests for Holochain applications
  • Creating multi-agent test scenarios
  • Ensuring data integrity in a distributed application

Getting Started

The starter code and detailed instructions are available in the challenge repository:

Blog App Validation Challenge Repository

You can view the difference between the starter code and the sample solution here.

Quick Setup

# Clone the repository
git clone https://github.com/CodeWithJV/holochain-challenge-3
cd holochain-challenge-3

# Enter the nix shell for development
nix develop

Tips

  • Focus on the validation callbacks in the integrity zome
  • Remember that validation must be deterministic across the network
  • Use the ValidationPackage to access necessary context for validation
  • Write test cases that specifically target your validation rules
  • For rate limiting, you’ll need to retrieve the agent’s previous actions
  • Test both successful and failing scenarios to ensure validation works correctly

Requirements

  1. Content Validation

    • Add character limits for posts (min/max length)
    • Implement validation for comment content
    • Create validation for post titles (no empty titles, reasonable length)

  2. Privilege Validation

    • Ensure only the original author can update or delete their posts
    • Implement validation for comment authorship
    • Add validation to prevent tampering with author links

  3. Rate Limiting

    • Create validation rules to prevent spam (limit posts per timeframe)
    • Implement rate limiting for comments

  4. Tests with Tryorama

    • Write tests to verify all CRUD operations
    • Create multi-agent test scenarios
    • Test validation rules to ensure they properly reject invalid data
    • Implement tests for edge cases

  5. Test Coverage

    • Ensure tests cover all main functionality
    • Include both positive tests (valid operations) and negative tests (operations that should fail)