Testing Mirth Connect: Introducing Mirth Tools for Clinical Data Workflows

In healthcare interoperability, Mirth Connect (aka NextGen Connect) is a cornerstone for moving data between systems. However, as integration projects grow in complexity, ensuring that transformations are accurate and robust becomes a significant challenge. Unit testing Mirth channels has traditionally been a manual and often tedious process.

To address this, I’ve been working on a utility called mirth-tools. It’s a humble attempt to streamline the development lifecycle for Mirth transformations, making testing and validation a built-in part of the process rather than an afterthought.

Why Mirth Tools?

The goal of this project is simple: enable developers to write and run tests against their Mirth transformations with the same ease they would in any other modern software stack. Whether you are validating HL7v2 syntax or checking if a complex transformation correctly maps fields to a JSON response, mirth-tools provides the infrastructure to do it locally and consistently.

Key Features

1. Local Development with Docker

Setting up a reproduction environment for Mirth can be a hassle. mirth-tools includes a pre-configured Docker Compose setup that spins up a clean Mirth instance with all necessary custom libraries pre-loaded.

make start

2. Streamlined Unit Testing

Tests are defined using static files. For every HL7v2 request, you can define an expected JSON response. The utility handles the execution and provides a clear diff if something goes wrong.

make run-tests

This generates a standard JUnit report (results/report.xml), which can be easily integrated into CI/CD pipelines or attached to Jira tickets for documentation and proof of validation.

3. HL7v2 Validation

Validation is critical. The tool includes a custom HL7v2 validation library that supports both standard syntax checks and profile-based validation. This allows you to catch errors early, such as invalid date formats or missing required segments, before they hit your production environment.

4. Dynamic Documentation

Keeping documentation in sync with code is hard. Using MkDocs, mirth-tools allows you to generate both static and dynamic documentation directly from your transformation projects.

Moving Forward

This tool is still evolving, and while it already serves our needs for simplifying Mirth testing, there is always room for improvement. By making testing more accessible, we can build more reliable healthcare systems and spend less time debugging integration issues.

I hope this utility proves useful to others in the healthcare integration space.