Spine Validation — TypeScript Client Library

A TypeScript validation library for Protobuf messages using Spine Validation options, built on @bufbuild/protobuf (Protobuf-ES v2).

🔧 This library is in its experimental stage, the public API should not be considered stable.

💡 Why Use This?

For Spine Event Engine Users

This library lets you:

• ✅ Reuse the same validation rules in your frontend that you defined in your backend.
• ✅ Maintain a single source of truth — validation logic lives in your .proto files.
• ✅ Keep frontend and backend validation in sync automatically.
• ✅ Get type-safe validation with full TypeScript support.
• ✅ Display the same error messages to users that your backend generates.

For New Users

Even if you're not using Spine Event Engine, this library provides a powerful way to add runtime validation to your Protobuf-based TypeScript applications:

• ✅ Define validation in .proto files using declarative Spine Validation options.
• ✅ Type-safe, runtime validation for your Protobuf messages.
• ✅ Clear, customizable error messages for better UX.
• ✅ Works with Protobuf-ES v2 and modern tooling.
• ✅ Extensible architecture for custom validation logic.

✨ Features

Comprehensive Validation Support

• (required) — Ensure fields have non-default values.
• (pattern) — Regex validation for strings.
• (min) / (max) — Numeric bounds with inclusive/exclusive support.
• (range) — Bounded ranges with bracket notation (min..max].
• (distinct) — Enforce uniqueness in repeated fields.
• (validate) — Recursive nested message validation.
• (goes) — Field dependency constraints.
• (require) — Complex required field combinations with boolean logic.
• (choice) — Require that a oneof group has at least one field set.

Developer Experience

• 🚀 Full TypeScript type safety.
• 📝 Custom error messages.
• 🧪 200+ comprehensive tests.
• 📚 Extensive documentation.
• 🎨 Clean, readable error formatting.

⚠️ Known Limitations

• (set_once) — Not currently supported. This option requires state tracking across multiple validations, which is outside the scope of single-message validation.

🚀 Getting Started

See the package-level README for complete installation instructions and usage guide.

Quick install:

npm install @spine-event-engine/validation-ts@snapshot @bufbuild/protobuf

---

📦 What's Included

This repository is structured as an npm workspace:

validation-ts/
├── packages/
│   ├── spine-validation-ts/     # 📦 Main validation package
│   │   ├── src/                 # Source code
│   │   ├── tests/               # 200+ comprehensive tests
│   │   ├── proto/               # Spine validation proto definitions
│   │   └── README.md            # Full package documentation
│   │
│   └── example/                 # 🎯 Example project
│       ├── proto/               # Example proto files
│       ├── src/                 # Example usage code
│       └── README.md            # Example documentation
│
└── README.md                    # You are here

🎓 Documentation

See the package-level README for more details.

---

🛠️ Development

Setup

# Clone the repository
git clone <repository-url>
cd validation-ts

# Install dependencies
npm install

Build & Test

# Build the validation package
npm run build

# Run all tests
npm test

# Run the example project
npm run example

Workspace Scripts

Command	Description
npm run build	Build the validation package
npm test	Run all validation tests
npm run example	Run the example project

---

🤝 Contributing

Contributions are welcome! Please ensure:

1. All tests pass: npm test
2. Code follows existing patterns
3. New features include tests
4. Documentation is updated

---

📄 License

Apache 2.0.

---

🔗 Related Projects

• Protobuf-ES — Protocol Buffers for ECMAScript
• Buf — Modern Protobuf tooling

---

Made with ❤️ for the Spine Event Engine ecosystem.

Documentation · Examples · Report Bug