What Do You Mean Test Coverage?! Efficient Testing for Shiny Apps

You can view Martin's R/Pharma 2023 workshop "Developing and Testing your Shiny Application" at    • Developing & Testing Your Shiny Appli...  

Abstract

This talk takes a deep dive into the world of testing shiny applications, covering strategies for determining what needs to be tested to ensure your app's functional accuracy and reliability. Shiny's reactive programming model requires specialized approaches to testing, distinct from traditional R package testing.

I'll begin by describing the application of unit, integration, and end-to-end testing in Shiny apps. Then we'll move into the role of testing in development and highlight the need for code organization when designing your testing suite.

The focus then shifts to practical aspects of testing by illustrating tools like test data and fixtures. Attendees will see example tests for utility functions, modules, and tests to capture specific user interactions (and confirm the application behaves as expected).

Finally, I will demonstrate advanced topics like test coverage, what it measures, and why 100% coverage isn't necessarily a metric worth chasing.

This presentation will give R developers a toolkit of testing techniques (building a test suite, writing effective tests, and automated testing) regardless of their familiarity with Shiny.

Presenter Biography

Martin Frigaard is a Data Visualization Engineer at Atorus, specializing in developing impactful applications and decision-making tools. With a diverse background that includes developing statistical tools at organizations like BioMarin and The Diabetes Technology Society, contributing to the award-winning "Data Journalism in R," and being a former Data journalism lecturer at California State University, Chico, Martin has a wealth of experience creating data visualizations, dashboards and statistical tools. He also holds graduate degrees in Clinical Research and Exercise Science and honorably served as a US Army medic.