Add SHINYLIVE_WASM_PACKAGES environment variable (#116)

* Add `SHINYLIVE_WASM_PACKAGES` environment var

* Move parse checking into shared helper function

* Update NEWS.md

NEWS.md

@@ -1,5 +1,7 @@
 # shinylive (development version)
 
+* In CI and other automated workflow settings the `SHINYLIVE_WASM_PACKAGES` environment variable can now be used to control whether WebAssembly R package binaries are bundled with the exported shinylive app, in addition to the `wasm_packages` argument of the `export()` function. (#116)
+
 * shinylive now avoids bundling WebAssembly R package dependencies listed only in the `LinkingTo` section of required packages. With this change dependencies that are only required at build time are no longer included as part of the exported WebAssembly asset bundle. This reduces the total static asset size and improves the loading time of affected shinylive apps. (#115)
 
 # shinylive 0.2.0

R/export.R

@@ -10,8 +10,11 @@
 #'   `shinylive.quiet` option or defaults to `FALSE` in interactive sessions if
 #'   not set.
 #' @param verbose Deprecated, please use `quiet` instead.
-#' @param wasm_packages Download and include binary WebAssembly packages as
-#'   part of the output app's static assets. Defaults to `TRUE`.
+#' @param wasm_packages Download and include binary WebAssembly packages as part
+#'   of the output app's static assets. Logical, defaults to `TRUE`. The default
+#'   value can be changed by setting the environment variable
+#'   `SHINYLIVE_WASM_PACKAGES` to `TRUE` or `1` to enable, `FALSE` or `0` to
+#'   disable.
 #' @param package_cache Cache downloaded binary WebAssembly packages. Defaults
 #'   to `TRUE`.
 #' @param max_filesize Maximum file size for bundling of WebAssembly package
@@ -61,7 +64,7 @@ export <- function(
   ...,
   subdir = "",
   quiet = getOption("shinylive.quiet", !is_interactive()),
-  wasm_packages = TRUE,
+  wasm_packages = NULL,
   package_cache = TRUE,
   max_filesize = NULL,
   assets_version = NULL,
@@ -84,6 +87,8 @@ export <- function(
     assets_version <- assets_version()
   }
 
+  wasm_packages <- wasm_packages %||% sys_env_wasm_packages()
+
   if (!fs::is_dir(appdir)) {
     cli::cli_abort("{.var appdir} must be a directory, but was provided {.path {appdir}}.")
   }

R/packages.R

@@ -1,11 +1,22 @@
 SHINYLIVE_DEFAULT_MAX_FILESIZE <- "100MB"
+SHINYLIVE_WASM_PACKAGES <- TRUE
 
 # Sys env maximum filesize for asset bundling
 sys_env_max_filesize <- function() {
   max_fs_env <- Sys.getenv("SHINYLIVE_DEFAULT_MAX_FILESIZE")
   if (max_fs_env == "") NULL else max_fs_env
 }
 
+sys_env_wasm_packages <- function() {
+  pkgs_env <- Sys.getenv("SHINYLIVE_WASM_PACKAGES", SHINYLIVE_WASM_PACKAGES)
+  pkgs_env <- switch(pkgs_env, "1" = TRUE, "0" = FALSE, pkgs_env)
+  wasm_packages <- as.logical(pkgs_env)
+  if (is.na(wasm_packages)) {
+    cli::cli_abort("Could not parse `wasm_packages` value: {.code {pkgs_env}}")
+  }
+  wasm_packages
+}
+
 # Resolve package list, dependencies listed in Depends and Imports
 resolve_dependencies <- function(pkgs, local = TRUE) {
   pkg_refs <- if (local) {

R/quarto_ext.R

@@ -253,11 +253,14 @@ build_app_resources <- function(app_json) {
     }
   })
 
-  # Download wasm binaries ready to embed into Quarto deps
-  withr::with_options(
-    list(shinylive.quiet = TRUE),
-    download_wasm_packages(appdir, destdir, package_cache = TRUE, max_filesize = NULL)
-  )
+  wasm_packages <- sys_env_wasm_packages()
+  if (wasm_packages) {
+    # Download wasm binaries ready to embed into Quarto deps
+    withr::with_options(
+      list(shinylive.quiet = TRUE),
+      download_wasm_packages(appdir, destdir, package_cache = TRUE, max_filesize = NULL)
+    )
+  }
 
   # Enumerate R package Wasm binaries and prepare the VFS images as html deps
   webr_dir <- fs::path(destdir, "shinylive", "webr")

tests/testthat/test-export.R

@@ -152,6 +152,16 @@ test_that("export - include R package in wasm assets", {
   app_dir <- test_path("apps", "app-utf8")
   asset_package <- c("utf8")
 
+  # No external dependencies exported
+  expect_silent_unattended({
+    withr::with_envvar(
+      list("SHINYLIVE_WASM_PACKAGES" = "FALSE"),
+      export(app_dir, out_dir)
+    )
+  })
+  expect_length(dir(pkg_dir), 0)
+  unlink_path(out_dir)
+
   # Default filesize 100MB
   expect_silent_unattended({
     export(app_dir, out_dir)