R: Test Shiny applications with 'testthat'

test_app {shinytest2}

R Documentation

Test Shiny applications with testthat

Description

This is a helper method that wraps around testthat::test_dir() to test your Shiny application or Shiny runtime document. This is similar to how testthat::test_check() tests your R package but for your app.

Usage

test_app(
  app_dir = missing_arg(),
  ...,
  name = missing_arg(),
  check_setup = TRUE,
  reporter = testthat::get_reporter(),
  stop_on_failure = missing_arg()
)

Arguments

`app_dir`	The base directory for the Shiny application. If `app_dir` is missing and `test_app()` is called within the `./tests/testthat.R` file, the parent directory (`"../"`) is used. Otherwise, the default path of `"."` is used.
`...`	Parameters passed to `testthat::test_dir()`
`name`	Name to display in the middle of the test name. This value is only used when calling `test_app()` inside of testhat test. The final testing context will have the format of `"{test_context} - {name} - {app_test_context}"`.
`check_setup`	If `TRUE`, the app will be checked for the presence of `./tests/testthat/setup-shinytest2.R`. This file must contain a call to `load_app_env()`.
`reporter`	Reporter to pass through to `testthat::test_dir()`.
`stop_on_failure`	If missing, the default value of `TRUE` will be used. However, if missing and currently testing, `FALSE` will be used to seamlessly integrate the app reporter to `reporter`.

Details

Example usage:

## Interactive usage
# Test Shiny app in current working directory
shinytest2::test_app()

# Test Shiny app in another directory
path_to_app <- "path/to/app"
shinytest2::test_app(path_to_app)

## File: ./tests/testthat.R
# Will find Shiny app in "../"
shinytest2::test_app()

## File: ./tests/testthat/test-shinytest2.R
# Test a shiny application within your own {testthat} code
test_that("Testing a Shiny app in a package", {
  shinytest2::test_app(path_to_app)
})

Uploading files

When testing an application, all non-temp files that are uploaded should be located in the ./tests/testthat directory. This allows for tests to be more portable and self contained.

When recording a test with record_test(), for every uploaded file that is located outside of ./tests/testthat, a warning will be thrown. Once the file path has be fixed, you may remove the warning statement.

Different ways to test

test_app() is an opinionated testing function that will only execute testthat tests in the ./tests/testthat folder. If (for some rare reason) you have other non-testthat tests to execute, you can call shiny::runTests(). This method will generically run all test runners and their associated tests.

# Execute a single Shiny app's {testthat} file such as `./tests/testthat/test-shinytest2.R`
test_app(filter = "shinytest2")

# Execute all {testthat} tests
test_app()

# Execute all tests for all test runners
shiny::runTests()