process: fix omitting `--` from `process.execArgv`

This was essentially a typo that went unnoticed because we
didn’t have tests for this particular situation.

Fixes: https://github.com/nodejs/node/issues/24647

PR-URL: https://github.com/nodejs/node/pull/24654
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>

1 files changed, 13 insertions, 10 deletions

diff --git a/test/parallel/test-process-exec-argv.js b/test/parallel/test-process-exec-argv.js
index fec5699933..578ee7b5d1 100644
--- a/test/parallel/test-process-exec-argv.js
+++ b/test/parallel/test-process-exec-argv.js
@@ -27,16 +27,19 @@ const spawn = require('child_process').spawn;
 if (process.argv[2] === 'child') {
   process.stdout.write(JSON.stringify(process.execArgv));
 } else {
-  const execArgv = ['--stack-size=256'];
-  const args = [__filename, 'child', 'arg0'];
-  const child = spawn(process.execPath, execArgv.concat(args));
-  let out = '';
+  for (const extra of [ [], [ '--' ] ]) {
+    const execArgv = ['--stack-size=256'];
+    const args = [__filename, 'child', 'arg0'];
+    const child = spawn(process.execPath, [...execArgv, ...extra, ...args]);
+    let out = '';
 
-  child.stdout.on('data', function(chunk) {
-    out += chunk;
-  });
+    child.stdout.setEncoding('utf8');
+    child.stdout.on('data', function(chunk) {
+      out += chunk;
+    });
 
-  child.on('close', function() {
-    assert.deepStrictEqual(JSON.parse(out), execArgv);
-  });
+    child.on('close', function() {
+      assert.deepStrictEqual(JSON.parse(out), execArgv);
+    });
+  }
 }