Updates for rstudio/shiny#3998 (#264)

* Updates for rstudio/shiny#3998

* Just use legacy for both

* Set the option in the app itself

inst/apps/122-async-outputs/tests/testthat/test-mytest.R

@@ -1,7 +1,14 @@
 library(shinytest2)
 
 test_that("Migrated shinytest test: mytest.R", {
-  app <- AppDriver$new(load_timeout = 15000, seed = 100, shiny_args = list(display.mode = "normal"))
+  app <- AppDriver$new(
+    load_timeout = 15000, seed = 100, 
+    shiny_args = list(display.mode = "normal"),
+    # Use legacy datatable implementation just for the 
+    # info$datatable$colnames test below. We could, of course, 
+    # update that test, but it's also good to test the legacy.
+    options = list(shiny.legacy.datatable = TRUE)
+  )
 
   # Wait until an async value is available
   app$wait_for_value(output = "printa", timeout = 10 * 1000)

inst/apps/126-async-ticks/app.R

@@ -3,6 +3,9 @@ library(promises)
 library(future)
 plan(multisession)
 
+opts <- options(shiny.legacy.datatable = TRUE)
+onStop(function() options(opts))
+
 testForMissingRenderFunctions <- function() {
   # If we add any render functions, they should be added to this test app. This test
   # will make it obvious if we forget.