Make jsonlite::toJSON convert all objects

By default, toJSON won't convert objects with classes that aren't registered
explicitly. This caused errors when converting html_dependency objects.
Setting this option causes jsonlite to convert all objects, including
html_dependency objects.

R/shiny.R

@@ -80,7 +80,8 @@ createUniqueId <- function(bytes, prefix = "", suffix = "") {
 
 toJSON <- function(x, ..., digits = getOption("shiny.json.digits", 16)) {
   jsonlite::toJSON(x, dataframe = "columns", null = "null", na = "null",
-                   auto_unbox = TRUE, digits = digits, use_signif = TRUE, ...)
+                   auto_unbox = TRUE, digits = digits, use_signif = TRUE,
+                   force = TRUE, ...)
 }
 
 # Call the workerId func with no args to get the worker id, and with an arg to