feat: add replace arg to all use_external_XXX type functions

- replace arg added to function interfaces of
    - use_external_js_file
    - use_external_css_file
    - use_external_html_template
    - use_external_file
- for all cases, replace arg is passed down to check_file_exists()
and handled there; return NULL per default thus allows files to
be overwritten in the corresponding cases

R/use_files.R

@@ -8,6 +8,7 @@
 #' @param url String representation of URL for the file to be downloaded
 #' @param path String representation of the local path for the file to be implemented (use_file only)
 #' @param dir Path to the dir where the file while be created.
+#' @param replace logical; if \code{TRUE}, then external file is overwritten
 #'
 #' @note See `?htmltools::htmlTemplate` and `https://shiny.rstudio.com/articles/templates.html`
 #'     for more information about `htmlTemplate`.
@@ -22,7 +23,8 @@ use_external_js_file <- function(
   pkg = get_golem_wd(),
   dir = "inst/app/www",
   open = FALSE,
-  dir_create = TRUE
+  dir_create = TRUE,
+  replace = FALSE
 ) {
   old <- setwd(fs_path_abs(pkg))
   on.exit(setwd(old))
@@ -41,7 +43,7 @@ use_external_js_file <- function(
     new_file
   )
 
-  check_file <- check_file_exists(where)
+  check_file <- check_file_exists(where, replace)
   if (isFALSE(check_file)) return(invisible(FALSE))
 
   check_url <- check_url_valid(
@@ -71,7 +73,8 @@ use_external_css_file <- function(
   pkg = get_golem_wd(),
   dir = "inst/app/www",
   open = FALSE,
-  dir_create = TRUE
+  dir_create = TRUE,
+  replace = FALSE
 ) {
   old <- setwd(fs_path_abs(pkg))
   on.exit(setwd(old))
@@ -109,7 +112,7 @@ use_external_css_file <- function(
   )
   # no change to previous version
 
-  check_file <- check_file_exists(where)
+  check_file <- check_file_exists(where, replace)
   if (isFALSE(check_file)) return(invisible(FALSE))
   # previously
   # if (fs_file_exists(where)) {
@@ -151,7 +154,8 @@ use_external_html_template <- function(
   pkg = get_golem_wd(),
   dir = "inst/app/www",
   open = FALSE,
-  dir_create = TRUE
+  dir_create = TRUE,
+  replace = FALSE
 ) {
   old <- setwd(fs_path_abs(pkg))
   on.exit(setwd(old))
@@ -190,7 +194,7 @@ use_external_html_template <- function(
   )
   # no change to previous version
 
-  check_file <- check_file_exists(where)
+  check_file <- check_file_exists(where, replace)
   if (isFALSE(check_file)) return(invisible(FALSE))
   # previously
   # if (fs_file_exists(where)) {
@@ -233,7 +237,8 @@ use_external_file <- function(
   pkg = get_golem_wd(),
   dir = "inst/app/www",
   open = FALSE,
-  dir_create = TRUE
+  dir_create = TRUE,
+  replace = FALSE
 ) {
   old <- setwd(fs_path_abs(pkg))
   on.exit(setwd(old))
@@ -263,7 +268,7 @@ use_external_file <- function(
     name
   )
 
-  check_file <- check_file_exists(where)
+  check_file <- check_file_exists(where, replace)
   if (isFALSE(check_file)) return(invisible(FALSE))
   # previously
   # if (fs_file_exists(where)) {
@@ -544,11 +549,12 @@ get_new_dir <- function(
 
   fs_path_abs(dir)
 }
-check_file_exists <- function(where) {
-  if (fs_file_exists(where)) {
+check_file_exists <- function(where, replace) {
+  if (fs_file_exists(where) && isFALSE(replace)) {
     cat_exists(where)
     return(invisible(FALSE))
   }
+  # otherwise: func returns NULL silently which is on purpose!
 }
 check_url_valid <- function(
   url,