Data Constraints

Data Constraints is the easiest way to validate your data streams. Whether you have small JSON files or massive CSV dumps, this tool ensures your data isn't garbage.

🚀 Why Data Constraints?

• Rule-Based: Define your rules in simple JSON/YAML files. No coding required.
• Universal: Works with JSON and CSV out of the box.
• Developer Friendly: Written in JavaScript, typed with TypeScript.

⚡ Basic Use Case (At a glance)

Imagine you have a users.json file and you want to ensure all emails are valid.

1. Your Data (users.json):

[
  { "id": 1, "email": "[email protected]" },
  { "id": 2, "email": "bob-has-no-domain" }
]

2. Your Rules (config.json):

{
  "sources": {
    "users": { "type": "file", "path": "users.json", "format": "json" }
  },
  "constraints": [
    {
      "type": "format",
      "id": "valid-email",
      "service": "users",
      "field": "email",
      "regex": "^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$",
      "message": "Invalid email: {{email}}"
    }
  ]
}

3. Run and get results:

$ npx data-constraints validate --config config.json
[INFO] Validating data...
[valid-email] (format) Invalid email: bob-has-no-domain
Validation finished. Found 1 issues.

📦 Installation

To use as a CLI globally:

npm install -g data-constraints

Or install locally in your project:

npm install data-constraints

Then you can run npx data-constraints from your project folder.

🧠 Basic Concepts

Data Constraints works with three core files:

1. Data Files: Your actual data dumps in .json or .csv format.
2. Config File: A JSON file pointing the engine to your data and rules.
3. Constraints (Rules): The definitions of what is valid.

Rule Types at a Glance

• 📝 Format: Ensure strings look correct (e.g. Emails).
  • Example: "regex": "^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$"
• 🆔 Unique: Ensure no duplicate IDs exist across a file.
  • Example: "field": "employee_id"
• 🔗 Foreign Key: Ensure referenced IDs actually exist in another file.
  • Example: order.userId must exist in users.id

📚 Documentation

For full documentation, guides and advanced use cases, please check the docs/ directory.

• Key Concepts: Easy-to-understand explanation of file types and constraints.
• User Guide: The comprehensive guide to using the CLI and defining rules.
• Integration Guide: How to integrate the engine programmatically in Node.js.
• Examples: Runnable examples, ranging from simple to e-commerce.

🛠️ Features

| Feature | Description | | :--- | :--- | | Format Validation | Regex-based validation for strings (Emails, Phones, Codes). | | Unique Validation | Ensure IDs and codes are unique across your dataset. | | Foreign Keys | Validate relationships between different files (e.g. order.userId -> user.id). | | Multiple Reporters | Output results to Console, JSON, or Markdown files. |

🤝 Contributing

In Data Constraints contributions, bug reports, and feature requests are welcome. If you have ideas, just launch you PRs!

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.