ajv-geojson-shim

A Command-line utility that extends CLI for Ajv JSON schema validators to support GeoJSON files.

Problem

Popular CLI packages for the Ajv JSON schema validator do not support validating GeoJSON files directly if their extension is *.geojson. The behaviour has been described in issue 152 of the canonical but unmaintained Ajv CLI package.

Solution

ajv-geojson-shim is a bash script wrapper around existing Ajv CLI packages that adds GeoJSON support by:

1. Accepting all standard Ajv CLI arguments and options
2. Detecting .geojson files in the parameters
3. Creating temporary .json copies of those files
4. Passing the temporary files to the underlying Ajv validator
5. Cleaning up temporary files after validation

Requirements

Make sure you have installed either ajv-cli or the actively maintained @jirutka/ajv-cli. You can install them as local dependency or globally using the -g flag:

npm install -g ajv-cli # or
npm install -g @jirutka/ajv-cli

Installation

Manual Installation: Clone this repository, make the script executable:

git clone https://github.com/tomkyle/ajv-geojson-shim.git

Install to your PATH: This step is optional. It will copy the script to ~/.local/bin/. Make sure this directory is in your $PATH variable.

make install

Usage

ajv-geojson-shim validate -s schema.json -d data.geojson

The script supports all commands and options of the underlying Ajv CLI package. Some examples:

# Validate a GeoJSON file against a schema
ajv-geojson-shim validate -s schema.json -d data.geojson

# Validate multiple files, including both JSON and GeoJSON
ajv-geojson-shim validate -s schema.json -d data1.json data2.geojson

# Test a schema with a GeoJSON file
ajv-geojson-shim test -s schema.json -d data.geojson

Development

Project Structure

ajv-geojson-shim/
├── bin/
│   └── ajv-geojson-shim     # Main script
├── test/
│   ├── test-unit.sh         # Unit tests
│   ├── test-integration.sh  # Integration tests
│   ├── test-helpers.sh      # Test helpers
│   └── fixtures/            # Fixture files
│       ├── *.json           # Example JSON and schema 
│       └── *.geoson         # Example GeoJSON
├── Makefile                 # Build and test automation
└── README.md                # Documentation

Testing

The project includes both unit tests and integration tests:

# Run all tests
make test

# Run only unit/integration tests
make unit-test
make integration-test

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the project
2. Create your feature branch: git checkout -b feature/amazing-feature
3. Make your changes
4. Run tests to ensure they pass: make test
5. Commit your changes: git commit -m 'Add some amazing feature'
6. Push to the branch: git push origin feature/amazing-feature
7. Open a Pull Request

Acknowledgements

• Ajv JSON Schema Validator
• ajv-cli
• @jirutka/ajv-cli

License

MIT License - Copyright (c) 2025 Carsten Witt