fix: ubuntu loop waiting for sub processes

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2019 Remy Sharp, https://remysharp.com <remy@remysharp.com>
+Copyright (c) 2010 - present, Remy Sharp, https://remysharp.com <remy@remysharp.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

lib/monitor/run.js

@@ -1,4 +1,4 @@
-var debug = require('debug')('nodemon');
+var debug = require('debug')('nodemon:run');
 const statSync = require('fs').statSync;
 var utils = require('../utils');
 var bus = utils.bus;
@@ -10,34 +10,12 @@ var watch = require('./watch').watch;
 var config = require('../config');
 var child = null; // the actual child process we spawn
 var killedAfterChange = false;
-var noop = function () { };
+var noop = () => {};
 var restart = null;
 var psTree = require('pstree.remy');
 var path = require('path');
 var signals = require('./signals');
 
-function waitForSubprocesses(subprocesses, callback) {
-  if (Array.isArray(subprocesses) && subprocesses.length > 0) {
-    // check if all old subprocesses have been terminated
-    exec('kill -0 ' + subprocesses.join(' '), (error) => {
-      const returnCode = error ? error.code : 0;
-      if (returnCode < 126) { // ignore command not found error
-        const stillRunning = subprocesses.length - returnCode;
-        if (stillRunning > 0) {
-          utils.log.status('still waiting for ' + stillRunning +
-            ' subprocess(es) to finish...');
-          setTimeout(waitForSubprocesses.bind(this, subprocesses, callback),
-            100);
-          return;
-        }
-      }
-      callback();
-    });
-  } else {
-    callback();
-  }
-}
-
 function run(options) {
   var cmd = config.command.raw;
 
@@ -55,11 +33,11 @@ function run(options) {
   var stdio = ['pipe', 'pipe', 'pipe'];
 
   if (config.options.stdout) {
-    stdio = ['pipe', process.stdout, process.stderr];
+    stdio = ['pipe', process.stdout, 'pipe'];
   }
 
   if (config.options.stdin === false) {
-    stdio = [process.stdin, process.stdout, process.stderr];
+    stdio = [process.stdin, process.stdout, 'pipe'];
   }
 
   var sh = 'sh';
@@ -161,6 +139,20 @@ function run(options) {
         bus.emit('message', message, sendHandle);
       });
     }
+  } else { // else if not required…
+
+    // this swallows a shell message that happens because we kill the sh -c
+    // more details here: https://git.io/Je6d0
+    child.stderr.on('data', s => {
+      s = s.toString();
+
+      if (child.__nodemonRestart) { // this flag is set right before the kill
+        utils.log.detail('stderr: ' + s);
+        return;
+      }
+
+      process.stderr.write(s);
+    });
   }
 
   bus.emit('start');
@@ -284,6 +276,7 @@ function run(options) {
       /* Now kill the entire subtree of processes belonging to nodemon */
       var oldPid = child.pid;
       if (child) {
+        child.__nodemonRestart = true;
         kill(child, config.signal, function () {
           // this seems to fix the 0.11.x issue with the "rs" restart command,
           // though I'm unsure why. it seems like more data is streamed in to
@@ -340,6 +333,19 @@ function run(options) {
   }
 }
 
+function waitForSubProcesses(pid, callback) {
+  debug('checking ps tree for pids of ' + pid);
+  psTree(pid, (err, pids) => {
+    if (!pids.length) {
+      return callback();
+    }
+
+    utils.log.status(`still waiting for ${pids.length} sub-process${
+      pids.length > 2 ? 'es' : ''} to finish...`);
+    setTimeout(() => waitForSubProcesses(pid, callback), 1000);
+  });
+}
+
 function kill(child, signal, callback) {
   if (!callback) {
     callback = function () { };
@@ -362,26 +368,25 @@ function kill(child, signal, callback) {
     // an array of PIDs that have spawned under nodemon, and we send each the
     // configured signal (default: SIGUSR2) signal, which fixes #335
     // note that psTree also works if `ps` is missing by looking in /proc
-    const sig = signal.replace('SIG', '');
-    psTree(child.pid, function (err, subprocesses) {
-      if (psTree.hasPS) {
-        spawn('kill', ['-s', sig].concat(subprocesses))
-          .on('close', waitForSubprocesses.bind(this, subprocesses,
-            function () {
-              spawn('kill', ['-s', sig, child.pid])
-                .on('close', callback);
-            }));
-      } else {
-        // make sure we kill from smallest to largest
-        const pids = subprocesses.slice().sort();
-        pids.forEach(pid => {
-          exec('kill -' + signals[signal] + ' ' + pid, () => { });
-        });
-        waitForSubprocesses(subprocesses, function () {
-          exec('kill -' + signals[signal] + ' ' + child.pid, () => { });
-          callback();
-        })
+    let sig = signal.replace('SIG', '');
+
+    psTree(child.pid, function (err, pids) {
+      // if ps isn't native to the OS, then we need to send the numeric value
+      // for the signal during the kill, `signals` is a lookup table for that.
+      if (!psTree.hasPS) {
+        sig = signals[signal];
       }
+
+      // the sub processes need to be killed from smallest to largest
+      debug('sending kill signal to ' + pids.join(', '));
+
+      pids.sort().forEach(pid => exec(`kill -${sig} ${pid}`, noop));
+
+      waitForSubProcesses(child.pid, () => {
+        // finally kill the main user process
+        exec(`kill -${sig} ${child.pid}`, callback);
+      });
+
     });
 
   }