readline/promises question results in unsettled top-level await when reading script from stdin

[mb21]

Version

v25.0.0 (also reproduced in v24.9.0)

Platform

Darwin Kernel Version 24.6.0: Mon Aug 11 21:16:52 PDT 2025; root:xnu-11417.140.69.701.11~1/RELEASE_ARM64_T8112 arm64

Subsystem

node:readline/promises

What steps will reproduce the bug?

Place this in test.js:

import { stdin, stdout } from "node:process";
import { createInterface } from "node:readline/promises";

const rl = createInterface({ input: stdin, output: stdout });
const answer = await rl.question("hi\n");
console.log(answer);

and run it with:

cat test.js | node

the above is important. node test.js works fine.

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

Always.

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

Program does not terminate.

What do you see instead?

Program terminates with exit code 13 and prints:

hi
Warning: Detected unsettled top-level await at file:///Users/me/test/[eval1]:5
const answer = await rl.question("hi");

Additional information

This seems related, but in my case I don't hit Ctrl-C: #53497

[aduh95]

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

Program does not terminate.

Why is that the expected behavior? What do you expect instead?

[mb21]

@aduh95 Why do I expect the program to not terminate? Because the example is pretty much verbatim from https://nodejs.org/api/readline.html#readline where it says:

Once this code is invoked, the Node.js application will not terminate until the readline.Interface is closed

Again, this happens only with cat test.js | node. So I imagine there's a bug in the stdin/eval handling somewhere.

Edit: ah, or do you think this doesn't work because stdin is already used to read in the script so I cannot use it anymore from the script itself?

[aduh95]

cat closes the stdin once it has read all the files you passed to it, so to me it seems to be working as expected. To clarify, cat test.js | node pipes the stdout of cat test.js into the stdin of node; if you try to re-use stdin from within node, you would find only the script you're trying to run (which is already closed by the time node runs the code since it needs to parse the full source before eval).

[mb21]

Ah, I'd sort of hoped I could use this to run an interactive installation wizard like curl https://mywebsite.com/install.js | node. But seems I'll just have to use npx then if this is not something node's stdin handling allows. Thanks, feel free to close this then.

[aduh95]

If you run curl https://mywebsite.com/install.js | node and input stuff in the terminal, it's going to curl's stdin, not node's. There's nothing special about Node.js btw, it's just how piping works in POSIX-complient systems.