close #481: emit a message when stop_server() is called (but no messa…

…ge when the R session is ending)

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: blogdown
 Type: Package
 Title: Create Blogs and Websites with R Markdown
-Version: 0.20.21
+Version: 0.20.22
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Beilei", "Bian", role = "ctb"),

R/serve.R

@@ -222,13 +222,17 @@ powershell = function(command) {
 #' @export
 #' @rdname serve_site
 stop_server = function() {
+  ids = NULL  # collect pids that we failed to kill
+  quitting = isTRUE(opts$get('quitting'))
   for (i in opts$get('pids')) {
     # no need to kill a process started by processx when R is quitting
-    if (isTRUE(opts$get('quitting')) && inherits(i, 'AsIs')) next
-    if (proc_kill(i, stdout = FALSE, stderr = FALSE) != 0) {
-      warning('Failed to kill the process ', i, '. You may need to kill it manually.')
-    }
+    if (quitting && inherits(i, 'AsIs')) next
+    if (proc_kill(i, stdout = FALSE, stderr = FALSE) != 0) ids = c(ids, i)
   }
+  if (length(ids)) warning(
+    'Failed to kill the process(es): ', paste(i, collapse = ' '),
+    '. You may need to kill them manually.'
+  ) else if (!quitting) message('The web server has been stopped.')
   opts$set(pids = NULL, served_dirs = NULL)
 }