test: fix parallel/test-setproctitle.js on alpine

Since Busybox ps does not support -p switch, using ps -o and grep
instead to get the process title and then check it.

PR-URL: https://github.com/nodejs/node/pull/12413
Fixes: https://github.com/nodejs/node/issues/12399
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>

test/parallel/test-setproctitle.js

@@ -14,7 +14,7 @@ const path = require('path');
 // The title shouldn't be too long; libuv's uv_set_process_title() out of
 // security considerations no longer overwrites envp, only argv, so the
 // maximum title length is possibly quite short.
-let title = 'testme';
+let title = 'test';
 
 assert.notStrictEqual(process.title, title);
 process.title = title;
@@ -25,7 +25,13 @@ if (common.isWindows) {
   return common.skip('Windows does not have "ps" utility');
 }
 
-exec(`ps -p ${process.pid} -o args=`, function callback(error, stdout, stderr) {
+// To pass this test on alpine, since Busybox `ps` does not
+// support `-p` switch, use `ps -o` and `grep` instead.
+const cmd = common.isLinux ?
+            `ps -o pid,args | grep '${process.pid} ${title}' | grep -v grep` :
+            `ps -p ${process.pid} -o args=`;
+
+exec(cmd, common.mustCall((error, stdout, stderr) => {
   assert.ifError(error);
   assert.strictEqual(stderr, '');
 
@@ -34,5 +40,5 @@ exec(`ps -p ${process.pid} -o args=`, function callback(error, stdout, stderr) {
     title += ` (${path.basename(process.execPath)})`;
 
   // omitting trailing whitespace and \n
-  assert.strictEqual(stdout.replace(/\s+$/, ''), title);
-});
+  assert.strictEqual(stdout.replace(/\s+$/, '').endsWith(title), true);
+}));