tests fail in devtools::check when Shiny app is structured as a package

sreinders · June 26, 2024, 2:12pm

Hello,

I have a Shiny app structured as an R package with several tests. The tests pass when I run devtools::test() but fail when I run devtools::check() with the error message

"Error ('test-examplemodule.R:2:3'): exampleModuleServer works
Error in eval(code, test_env): object 'exampleModuleServer' not found"

My code and an explanation of what I tried are below. If someone could help and let me know what I am doing wrong that would be much appreciated.

My Code

R/App.R

myApp <- function(...){
  ui <- shiny::fluidPage(
    # exampleModuleUI is defined in R/example-module.R
    shiny::h2("Modules example"),
    exampleModuleUI("examplemodule1", "Click counter #1"),
    exampleModuleUI("examplemodule2", "Click counter #2")
  )
  
  server <- function(input, output, session) {
    # exampleModuleServer is defined in R/example-module.R
    exampleModuleServer("examplemodule1")
    exampleModuleServer("examplemodule2")
  }
  
  shiny::shinyApp(ui, server)
}

R/example-module.R

exampleModuleUI <- function(id, label = "Counter") {
  # All uses of Shiny input/output IDs in the UI must be namespaced,
  # as in ns("x").
  ns <- shiny::NS(id)
  shiny::tagList(
    shiny::actionButton(ns("button"), label = label),
    shiny::verbatimTextOutput(ns("out"))
  )
}

exampleModuleServer <- function(id) {
  # moduleServer() wraps a function to create the server component of a
  # module.
  shiny::moduleServer(
    id,
    function(input, output, session) {
      count <- shiny::reactiveVal(0)
      shiny::observeEvent(input$button, {
        count(count() + 1)
      })
      output$out <- shiny::renderText({
        count()
      })
      count
    }
  )
}

tests/testthat/test-examplemodule.R

testthat::test_that("exampleModuleServer works", {
  shiny::testServer(exampleModuleServer, {
    # Set initial value of a button
    session$setInputs(button = 0)
  
    # Check the value of the reactiveVal `count()`
    expect_equal(count(), 1)
    # Check the value of the renderText()
    expect_equal(output$out, "1")
  
    # Simulate a click
    session$setInputs(button = 1)
  
    expect_equal(count(), 2)
    expect_equal(output$out, "2")
  })
})

tests/testthat/setup-shintytest2.R

# Load application support files into testing environment
shinytest2::load_app_env()

DESCRIPTION

Package: shinyTemplate
Title: What the Package Does (One Line, Title Case)
Version: 0.0.0.9000
Authors@R: 
    person("First", "Last", , "first.last@example.com", role = c("aut", "cre"),
           comment = c(ORCID = "YOUR-ORCID-ID"))
Description: What the package does (one paragraph).
License: GPL (>= 3)
Encoding: UTF-8
Roxygen: list(markdown = TRUE)
RoxygenNote: 7.3.1
Config/testthat/edition: 3
Imports: 
    shiny
Suggests:
    shinytest2,
    testthat

What I've Tried

The app works as expected with

devtools::load_all()
myApp()

The tests pass when I run devtools::test() but I get a warning:

devtools::test()

Testing shinyTemplate
| F W S OK | Context
| 4 | examplemodule

══ Results ════════════════════════════════════════════════════════════════════════════════════════════════
[ FAIL 0 | WARN 0 | SKIP 0 | PASS 4 ]
Warning message:
In warn_if_app_dir_is_package(appDir) :
Loading R/ subdirectory for Shiny application, but this directory appears to contain an R package. Sourcing files in R/ may cause unexpected behavior. See ?loadSupport for more details.

When I run devtools::check the tests fail

devtools::check()

── R CMD check results ────────────────────────────────────────────────────── shinyTemplate 0.0.0.9000 ────
Duration: 6s

❯ checking tests ...
See below...

── Test failures ──────────────────────────────────────────────────────────────────────────── testthat ────

shinytest2::test_app()
Loading required package: testthat
Loading required package: shiny
| F W S OK | Context

⠏ | 0 | examplemodule
| 1 0 | examplemodule
────────────────────────────────────────────────────────────────────────────────
Error ('test-examplemodule.R:2:3'): exampleModuleServer works
Error in eval(code, test_env): object 'exampleModuleServer' not found
Backtrace:
▆

└─shiny::testServer(...) at test-examplemodule.R:2:3
└─shiny:::isModuleServer(app)
────────────────────────────────────────────────────────────────────────────────

══ Results ═════════════════════════════════════════════════════════════════════
── Failed tests ────────────────────────────────────────────────────────────────
Error ('test-examplemodule.R:2:3'): exampleModuleServer works
Error in eval(code, test_env): object 'exampleModuleServer' not found
Backtrace:
▆

└─shiny::testServer(...) at test-examplemodule.R:2:3
└─shiny:::isModuleServer(app)

[ FAIL 1 | WARN 0 | SKIP 0 | PASS 0 ]
Error: Test failures
Execution halted

1 error | 0 warnings | 0 notes

Any help you could give would be much appreciated. Thank you!