Using `--test` causes process.argv[] to lose user-specified CLI flags

[broofa]

Version

v25.6.1

Platform

Darwin MacBookPro.lan 25.0.0 Darwin Kernel Version 25.0.0: Wed Sep 17 21:41:45 PDT 2025; root:xnu-12377.1.9~141/RELEASE_ARM64_T6000 arm64

Subsystem

node:test

What steps will reproduce the bug?

Create a file, "foo.js":

console.log(process.argv);

... then invoke node with a custom CLI flag (--hello), and without and with the --test flag:

# Run script with a custom CLI flag:
$ node foo.js --hello
[
  '/Users/kieffer/.nvm/versions/node/v25.6.1/bin/node',
  '/Users/kieffer/codepen/codewatch/packages/foo.js',
  '--hello'
]

# ... now add the `--test` fla
$ node --test foo.js --hello
[
  '/Users/kieffer/.nvm/versions/node/v25.6.1/bin/node',
  '/Users/kieffer/codepen/codewatch/packages/foo.js'
]
✔ foo.js (35.9505ms)
<snip>

Note

Running with the "--" flag (e.g. node foo.js -- --hello or node --test foo.js -- --hello) yields the same behavior.

How often does it reproduce? Is there a required condition?

Consistent.

What is the expected behavior? Why is that the expected behavior?

process.argv should include the user-provided CLI flag in both cases.

What do you see instead?

When running with --test, process.argv omits the user-supplied --hello flag.

This makes testing code that depends on process.argv problematic, obviously.