ping server until it's started up properly

DESCRIPTION

@@ -13,7 +13,8 @@ Imports:
     bslib,
     miniUI,
     rstudioapi,
-    flowr
+    flowr,
+    pingr
 Remotes:
     flowr=github::flowr-analysis/flowr-r-adapter
 License: GPL-3 + file LICENSE

R/node.R

@@ -3,7 +3,7 @@
 #' @export
 install_node_addin <- function() {
   base <- node_base_dir()
-  print(paste0("Installing Node.js and flowR Shell in ", base))
+  cat(paste0("Installing Node.js and flowR Shell in ", base, "\n"))
   node_ver <- read_flowr_pref(pref_node_version, default_node_version)
   assure_valid_semver(node_ver)
   flowr_ver <- read_flowr_pref(pref_flowr_version, default_flowr_version)
@@ -14,9 +14,9 @@ install_node_addin <- function() {
       flowr::install_flowr(flowr_ver, TRUE, base)
       # check if the flowr namespace exists
       if ("flowr" %in% rownames(utils::installed.packages())) {
-        print("Successfully installed Node.js and flowR Shell")
+        cat("Successfully installed Node.js and flowR Shell\n")
       } else {
-        stop("Failed to install flowR. Please check the R console for more information.")
+        stop("Failed to install flowR. Please check the R console for more information.\n")
       }
     },
     error = function(e) {

R/shell.R

@@ -47,10 +47,18 @@ make_flowr_session_storage <- function() {
           return()
         }
         cat(paste0("[flowR] Starting local flowR server with pid ", pid, "\n"))
+        # wait until the server has started up
+        waited <- 0
+        while (waited < 30 && is.na(sys::exec_status(pid, FALSE))) {
+          Sys.sleep(1)
+          waited <- waited + 1
+          cat(paste0("Waiting for flowR server to start up (", waited, "s)\n"))
+          if (!is.na(pingr::ping_port(default_server_host, default_server_port, count = 1))) {
+            break
+          }
+        }
         host <- default_server_host
         port <- default_server_port
-        # sleep a bit until the server has fully started up
-        Sys.sleep(5)
       } else {
         # connect externally
         cat("[flowR] Connecting to flowR server\n")
@@ -65,7 +73,7 @@ make_flowr_session_storage <- function() {
           stop(paste0("[flowR] Failed to connect to flowR server at ", host, ":", port, ": ", e))
         }
       )
-      print(conn_hello[[2]])
+      cat(paste0(conn_hello[[2]], "\n"))
       connection <<- conn_hello[[1]]
     } else {
       cat("[flowR] flowR server already connected\n")

R/slice.R

@@ -55,6 +55,6 @@ slice_addin <- function() {
 reconstruct_addin <- function() {
   result <- slice_addin()
   code <- result$results$reconstruct$code
-  cat(paste0("[flowR] Showing reconstruct view"))
+  cat(paste0("[flowR] Showing reconstruct view\n"))
   display_code(if(is.null(code)) "No reconstructed code available" else code)
 }