Unrendered plotly plots cause lexical error in app$get_values() #432
Description
When plotly plots are present in an app but not yet displayed, app$get_values() fails with the error:
{shinytest2} query failed (500)----------------------
URL: http://127.0.0.1:7484/session/74ff996c880f777d410d343fc8aed4aa/dataobj/shinytest?w=&nonce=e18d93f7b&input=1&output=1&export=1&format=rds&sortC=1
<html>
<head lang = "en">
<title>An error has occurred</title>
</head>
<body>
<h1>An error has occurred!</h1>
<p>lexical error: invalid char in json text.
NULL c("shiny.silent.error", "v
(right here) ------^
</p>
</body>
</html>
Please see the examples:
library(shiny)
library(shinytest2)
library(plotly)
shiny_app <- shinyApp(
fluidPage(
numericInput("n", "n", 0),
plotlyOutput("plot")
),
function(input, output) {
output$plot <- renderPlotly({
req(input$n > 0)
plot_ly(cars, x = ~speed, type = "histogram")
})
}
)
Works fine:
app <- AppDriver$new(shiny_app)
app$set_inputs("n" = 1)
app$get_values()
Does not:
app <- AppDriver$new(shiny_app)
app$get_values()
I am confused because this is currently breaking my tests when they ran fine recently (definitely in 2025) but I have tried with plotly v4.11.0, shinytest2 v0.4.1 and shiny v1.11.1 on another machine and still have the same problem.
> sessionInfo()
R version 4.5.2 (2025-10-31)
Platform: x86_64-pc-linux-gnu
Running under: Ubuntu 24.04.3 LTS
Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.12.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.12.0 LAPACK version 3.12.0
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8 LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=en_US.UTF-8
[8] LC_NAME=C LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
time zone: Europe/London
tzcode source: system (glibc)
attached base packages:
[1] stats graphics grDevices datasets utils methods base
other attached packages:
[1] plotly_4.11.0 ggplot2_4.0.1 shinytest2_0.5.0 testthat_3.3.2 shiny_1.12.1.9000
loaded via a namespace (and not attached):
[1] sass_0.4.10 generics_0.1.4 tidyr_1.3.2 bspm_0.5.7 digest_0.6.37 magrittr_2.0.3 evaluate_1.0.5 grid_4.5.2 RColorBrewer_1.1-3 fastmap_1.2.0
[11] jsonlite_2.0.0 processx_3.8.6 brio_1.1.5 ps_1.9.1 promises_1.5.0 httr_1.4.7 purrr_1.2.1 viridisLite_0.4.2 scales_1.4.0 jquerylib_0.1.4
[21] lazyeval_0.2.2 cli_3.6.5 rlang_1.1.6 cachem_1.1.0 withr_3.0.2 yaml_2.3.12 otel_0.2.0 tools_4.5.2 dplyr_1.1.4 httpuv_1.6.16
[31] vctrs_0.6.5 R6_2.6.1 mime_0.13 lifecycle_1.0.4 htmlwidgets_1.6.4 pkgconfig_2.0.3 callr_3.7.6 bslib_0.9.0 pillar_1.11.1 later_1.4.2
[41] gtable_0.3.6 glue_1.8.0 data.table_1.18.0 Rcpp_1.1.0 xfun_0.55 tibble_3.3.1 tidyselect_1.2.1 rstudioapi_0.17.1 knitr_1.51 farver_2.1.2
[51] xtable_1.8-4 otelsdk_0.2.2 htmltools_0.5.8.1 compiler_4.5.2 S7_0.2.1