404 for expected values

[simon-smart88]

Hello

I've encountered an error whilst testing:

Error in `app_expect_values(self, private, ..., input = input, output = output, 
    export = export, screenshot_args = screenshot_args, name = name, 
    cran = cran)`: Shiny server returned 404 for values URL: http://127.0.0.1:5711/session/bc777a48fd9d472a3a1f837f1ece2d67/dataobj/shinytest?w=&nonce=c7e7d7b16&input=1&output=1&export=1&format=json&sortC=1
ℹ Is `shiny::runApp(test.mode = TRUE)` enabled?
Backtrace:
    ▆
 1. └─app$expect_values() at test-shinytest2.R:16:2
 2.   └─shinytest2:::app_expect_values(...)
 3.     └─shinytest2:::app_httr_get(...)
 4.       └─shinytest2 (local) fn_404(req)
 5.         └─shinytest2:::app_abort(...)
 6.           └─rlang::abort(..., app = self, call = call)

I've managed to establish that it's caused by an interaction between my use of gargoyle and leaflet.extras. When the app either contains leaflet.extras::addDrawToolbar without gargoyle everything is fine, and similarly if I create a simple app using just gargoyle everything works fine. Here's an MRE and the test which fails to run: (what was extra confusing, is that I encountered this on my first use of shinytest2 and so I spent hours trying to enable test.mode = TRUE)

library(shiny)
library(leaflet)
library(leaflet.extras)
library(gargoyle)

shiny_app <- shinyApp(
  fluidPage(
    leafletOutput("map",width=500,height=500),
    verbatimTextOutput("coords")
  ),
  function(input, output) {

    output$map <- renderLeaflet(
      leaflet() %>%
        setView(0, 0, zoom = 2) %>%
        addProviderTiles('Esri.WorldTopoMap') %>%
        addDrawToolbar(polylineOptions=F,circleOptions = F, rectangleOptions = T, markerOptions = F, circleMarkerOptions = F, singleFeature = T,polygonOptions = F)
    )

    common_class <- R6::R6Class(
      classname = "common",
      public = list(
        poly = NULL
      )
    )
    gargoyle::init("change_poly")

    common <- common_class$new()

    observe({
      coords <- unlist(input$map_draw_new_feature$geometry$coordinates)
      xy <- matrix(c(coords[c(TRUE,FALSE)], coords[c(FALSE,TRUE)]), ncol=2)
      colnames(xy) <- c('longitude', 'latitude')
      common$poly <- xy
      gargoyle::trigger("change_poly")
    }) %>% bindEvent(input$map_draw_new_feature)

      output$coords <- renderText({
      common$poly}) %>% bindEvent(gargoyle::watch("change_poly"))
  }
)

test_that("{shinytest2} recording: testing_bug", {
  app <- AppDriver$new(name = "testing_bug", height = 909, width = 1379)
  app$set_inputs(map_groups = "editableFeatureGroup", allow_no_input_binding_ = TRUE)
  app$set_inputs(map_draw_start = "rectangle", allow_no_input_binding_ = TRUE)
  app$set_inputs(map_draw_new_feature = c("Feature", 76, "rectangle", "Polygon",
      c(c(2.460938, 18.312811), c(2.460938, 28.921631), c(15.820313, 28.921631),
          c(15.820313, 18.312811), c(2.460938, 18.312811))), allow_no_input_binding_ = TRUE)
  app$set_inputs(map_draw_all_features = c("FeatureCollection", c("Feature", 76,
      "rectangle", "Polygon", c(c(2.460938, 18.312811), c(2.460938, 28.921631), c(15.820313,
          28.921631), c(15.820313, 18.312811), c(2.460938, 18.312811)))), allow_no_input_binding_ = TRUE)
  app$set_inputs(map_draw_stop = "rectangle", allow_no_input_binding_ = TRUE)
  app$set_inputs(map_click = c(18.3128108464255, 15.8203125, 0.384901733059819),
      allow_no_input_binding_ = TRUE)
  app$expect_values()
})

[nick-youngblut]

I'm also getting a Shiny server returned 404 for values URL error.

The error seems to provide no information on the cause of the issue. Instead, one just gets "something went wrong, good luck fixing it". This leads to such tragedies as:

and so I spent hours trying to enable test.mode = TRUE

---

In my case, using shinytest2::record_test() provided a full log of the error. The cause of the error was a mis-named function.

[sckott]

Also running into this and would love better information on how to fix it