Don't fail in the shiny progress handler before the bar is shown (#762)

DESCRIPTION

@@ -40,6 +40,7 @@ Suggests:
     rmarkdown,
     rprojroot,
     rstudioapi,
+    shiny,
     testthat (>= 3.2.0),
     tibble,
     whoami,

NEWS.md

@@ -51,6 +51,9 @@
   error when the progress bar is drawn with a value below zero or above
   the total (#580, @taekop).
 
+* `cli_progress_output()` no longer fails with the Shiny progress handler
+  if the progress bar has not been shown yet (#762, @taekop).
+
 # cli 3.6.6
 
 * New `{.num}` and `{.bytes}` inline styles to format numbers

R/progress-server.R

@@ -392,10 +392,12 @@ builtin_handler_shiny <- list(
   output = function(bar, .envir, text) {
     bar$shiny_output <-
       last_lines(paste0(bar$shiny_output, " \u2022 ", text))
-    bar$shiny_progress$set(
-      value = bar$current,
-      detail = shiny_detail(bar, .envir)
-    )
+    if (!is.null(bar$shiny_progress)) {
+      bar$shiny_progress$set(
+        value = bar$current,
+        detail = shiny_detail(bar, .envir)
+      )
+    }
   }
 )
 

tests/testthat/test-progress-handlers.R

@@ -56,3 +56,18 @@ test_that("builtin_handlers", {
   expect_true(is.list(builtin_handlers()))
   expect_true(all(c("cli", "shiny", "rstudio") %in% names(builtin_handlers())))
 })
+
+test_that("shiny handler, cli_progress_output() before the bar is shown", {
+  skip_if_not_installed("shiny")
+  withr::local_options(
+    cli.progress_handlers_only = "shiny",
+    cli.progress_show_after = 3600
+  )
+  server <- function(input, output, session) {
+    id <- cli_progress_bar(total = 10)
+    cli_progress_output("custom message", id = id)
+    cli_progress_update(id = id)
+    cli_progress_done(id = id)
+  }
+  expect_no_error(shiny::testServer(server, {}))
+})