Fix exit logging to also support signals, and recursively kill child processes on Linux by default to avoid the children-of-children problem

package.json

@@ -19,6 +19,7 @@
   "author": "Sven Slootweg",
   "license": "WTFPL",
   "dependencies": {
+    "ps-tree": "^1.0.1",
     "stream-to-logger": "0.0.1"
   },
   "devDependencies": {

src/index.js

@@ -1,4 +1,6 @@
+const os = require("os");
 const childProcess = require("child_process");
+const psTree = require("ps-tree");
 const streamToLogger = require("stream-to-logger");
 
 module.exports = function runProcess(path, args, options) {
@@ -19,9 +21,35 @@ module.exports = function runProcess(path, args, options) {
 		}
 	});
 
-	proc.on("close", (code) => {
-		options.logger.info(`${path} exited with code ${code.toString()}.`);
+	proc.on("close", (code, signal) => {
+		if (code != null) {
+			options.logger.info(`${path} exited with code ${code.toString()}.`);
+		} else if (signal != null) {
+			options.logger.info(`${path} exited due to signal ${signal}.`);
+		} else {
+			options.logger.info(`${path} exited for an unknown reason.`);
+		}
 	});
 
+	let _kill = proc.kill.bind(proc);
+	proc.kill = function(signal) {
+		/* FIXME: Are other UNIX-y platforms also affected by the killing-children-of-children issue? And do they have `ps` with the same flags? */
+		if (os.platform() === "linux") {
+			psTree(proc.pid, (err, children) => {
+				if (err != null) {
+					console.error(`WARN: Could not kill children of PID ${proc.pid}: ${err.message}`);
+					console.error(err.stack);
+					_kill(signal);
+				} else {
+					childProcess.execFile("kill", children.map((child) => child.PID), (err, stdout, stderr) => {
+						_kill(signal);
+					});
+				}
+			})
+		} else {
+			_kill(signal);
+		}
+	}
+
 	return proc;
 }