WIP feat: Allow for packages to be dynamically loaded in app

R/app-driver-start.R

@@ -1,6 +1,8 @@
+internal_shinytest2_value <- TRUE
 
 app_start_shiny <- function(
   self, private,
+  ...,
   seed = NULL,
   load_timeout = 10000,
   shiny_args = list(),
@@ -20,6 +22,14 @@ app_start_shiny <- function(
     # Load the app's .Rprofile / .Renviron if possible
     withr::local_dir(self$get_dir())
 
+    # Find the package name if we're running in a package
+    package_name <- testthat::testing_package()
+    if (!nzchar(package_name)) package_name <- NULL
+    # How to load the package is determined by the testthat context
+    # * If we're `test_check()`ing, we should load the installed package
+    # * Otherwise, we should source the R files before loading the app
+    load_package <- if (testthat::is_checking()) "installed" else "source"
+
     callr::r_bg(
       stdout = sprintf(tempfile_format, "shiny-stdout"),
       stderr = sprintf(tempfile_format, "shiny-stderr"),
@@ -31,9 +41,21 @@ app_start_shiny <- function(
         seed = seed,
         rng_kind = rng_kind,
         render_args = render_args,
-        options = options
+        options = options,
+        package_name = package_name,
+        load_package = load_package
       ),
-      function(app_dir, shiny_args, has_rmd, seed, rng_kind, render_args, options) {
+      function(
+        app_dir,
+        shiny_args,
+        has_rmd,
+        seed,
+        rng_kind,
+        render_args,
+        options,
+        package_name,
+        load_package
+      ) {
 
         if (!is.null(seed)) {
           # Prior to R 3.6, RNGkind has 2 args, otherwise it has 3
@@ -48,6 +70,18 @@ app_start_shiny <- function(
         # options[["shiny-testmode-html-dep"]] <- getTracerDep()
         do.call(base::options, options)
 
+        # Add testthat to app's environment
+        library(testthat)
+        testthat___test_files_setup_env <- getFromNamespace("test_files_setup_env", "testthat")
+
+        test_env = testthat___test_files_setup_env(
+          test_package = package_name,
+          test_dir = app_dir,
+          load_package = load_package,
+          env = NULL
+        )
+        withr::local_environment(test_env)
+
         # Return value is important for `AppDriver$stop()`
         # Do not add code after this if else block
         if (has_rmd) {

tests/testthat/apps/test-env/app.R

@@ -0,0 +1,19 @@
+library(shiny)
+
+# Test for internal value
+# This is defined within shinytest2's ./R/app-driver-start.R
+# and will only allow the app to run if the app has access to shinytest2's internal functions
+# or the "local package" values.
+value <- internal_shinytest2_value
+
+ui <- fluidPage(
+  tags$h1("Internal test value:"),
+  verbatimTextOutput("value", placeholder = TRUE),
+)
+server <- function(input, output, session) {
+  output$value <- renderText({
+    value
+  })
+}
+
+shinyApp(ui, server)

tests/testthat/apps/test-env/tests/testthat.R

@@ -0,0 +1 @@
+shinytest2::test_app()

tests/testthat/apps/test-env/tests/testthat/setup.R

@@ -0,0 +1 @@
+shinytest2::load_app_env()

tests/testthat/apps/test-env/tests/testthat/test-app-env.R

@@ -0,0 +1,6 @@
+
+test_that("local pkg env is loaded", {
+  expect_equal(internal_shinytest2_value, TRUE)
+
+  AppDriver$new(variant = NULL)
+})