Tests

Expand the callout boxes below to review what we’ve covered in the previous chapters on debugging:

Review Chapters 10 - 13

Debuggers (Chapter 10)

In the Debuggers chapter we covered:

• 10.1 Interactive debugging
  • 10.1.1 Reactive browsing
  • 10.2.1 IDE Changes
  • 10.2.2 Variables and values
  • 10.2.3 Inspecting variables
  • 10.2.4 Inspecting values

Print debugging (Chapter 11)

In the Print debugging chapter we covered:

• 11  Print debugging
  • 11.2 Reactive printing
  • 11.3 Reactive values

Debugging apps (Chapter 12)

In the Debugging apps chapter we covered:

• 12.1 Abstract syntax trees
• 12.2 Debugging modules
  • 12.2.1 Input modules
• 12.3 UI function debugging
• 12.4 Server function debugging
• 12.5 Module communication
  • 12.5.1 Verifying inputs

Logging (Chapter 13)

In the Logging chapter we covered:

• 13.1 Why Use Logging?
  • 13.1.1 App architecture
  • 13.1.2 Validating inputs
  • 13.1.3 Handling errors
• 13.2 Base R logging
  • 13.2.1 Logging events
  • 13.3 Logging with logger
  • 13.3.1 Log levels
  • 13.3.2 Storing log files
  • 13.3.3 Custom logger functions
• 13.4 Logging and debugging
  • 13.4.1 App architecture
• 13.5 Package startup messages
  • 13.5.1 .onAttach()

Testing your app

We’re now ready to test the code and features in our app-package. The next section covers the following topics:

Test suite

Test suite starts by showing how to create the testthat infrastructure then, dives into creating test files, the mechanics unit tests and expectations, and running tests during development:

• 14.2 Setting up testthat tests
• 14.3 Creating unit tests
  • 14.3.2 test_that() tests
  • 14.3.3 expect_ations
  • 14.3.4 BDD test functions
• 14.4 Running tests
  • 14.4.1 Keyboard shortcuts

Specifications

Specifications discusses how to collect and organize information to write tests for your application:

• 15.1 Application requirements
  • 15.1.1 User Specifications
  • 15.1.2 Features, and
  • 15.1.3 Functional Requirements
• 15.3 BDD and testthat
  
• 15.4 Traceability Matrix

This chapter also gives examples of behavior-driven development tests features and how to track specifications and tests together.

Test tools

Test tools was updated recently to include the new ensure package, which was designed for “drafting testthat unit testing code using LLMs.”

• 16.1 Unit tests & LLMs
  • 16.1.2 Test scope
    
  • 16.1.3 Test fixtures
    
• 16.2 Test data
• 16.3 Test logging
  • 16.3.1 Test helpers
  • 16.3.2 Test development
    
• 16.4 Test snapshots
  • 16.4.1 Reviewing _snaps/

Each tool can contribute to testing your Shiny app-package in a unique way (they’re also relatively recent additions to the testthat framework).

Testing modules

Shiny’s testServer() function can be useful for performing integration tests with module server functions. Testing modules gives examples of using testServer() to verify module communication (i.e., passing data between modules):

• 17.2 Testing return values
  
• 17.3 Testing module inputs
  
• 17.4 Module test coverage
  
• 17.4.1 Testing module outputs

System tests

The final chapter in this section covers setting up and running system (or end-to-end tests with shinytest2):

• 18.2 Setting up shinytest2
  
• 18.3 Record a test
  
• 18.4 shinytest2 and BDD
  
• 18.5 The test.mode option

See a typo, error, or something missing?

Please open an issue on GitHub