Typing `import("").` locks up node repl and gets caught in a error loop

[BlankParticle]

Version

v26.5.0

Platform

Darwin Yoru.local 27.0.0 Darwin Kernel Version 27.0.0: Mon Jun 29 21:25:02 PDT 2026; root:xnu-13432.0.50.501.3~1/RELEASE_ARM64_T6041 arm64

Subsystem

repl

What steps will reproduce the bug?

1. type node to start the node repl
2. type import(""). or any non existent module
3. Watch your repl get locked up and hundreds of module not found errors starts filling up your terminal

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

Always, tested in node v24 and v26, typing or pasting both works

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

Repl is trying to import the module to evaluate the object for completion, but the module doesn't exist which causes errors to fill up the terminal

the error should be properly captured and show up in the predictive area like in this screenshot

What do you see instead?

The console starts filling up with

> Uncaught:).
Error: Cannot find package '/Users/blank/Projects/BlankParticle/node_modules/index.js' imported from /Users/blank/Projects/BlankParticle/repl
    at legacyMainResolve (node:internal/modules/esm/resolve:202:26)
    at packageResolve (node:internal/modules/esm/resolve:796:12)
    at moduleResolve (node:internal/modules/esm/resolve:873:18)
    at defaultResolve (node:internal/modules/esm/resolve:1006:11)
    at #cachedDefaultResolve (node:internal/modules/esm/loader:708:20)
    at #resolveAndMaybeBlockOnLoaderThread (node:internal/modules/esm/loader:728:38)
    at ModuleLoader.resolveSync (node:internal/modules/esm/loader:766:56)
    at #resolve (node:internal/modules/esm/loader:690:17)
    at ModuleLoader.getOrCreateModuleJob (node:internal/modules/esm/loader:610:35) {
  code: 'ERR_MODULE_NOT_FOUND'
}

and it locks up the entire repl, ctrl C works to kill the repl, but sometimes you need to kill the process from another console

Screen.Recording.2026-07-15.at.22.53.21.mov

Additional information

No response

[MikeMcC399]

I couldn't reproduce on Ubuntu 24.04.4 LTS or Windows 11 25H2.

Possibly this is a Darwin-only problem?

[BlankParticle]

I tested different terminal on Darwin, Node in a docker container, on a Linux VPS running Ubuntu 25.10 and a Windows 11 system, I was able to reproduce in all of these conditions

Windows.PowerShell.2026-07-15.23-32-28.mp4

I think you probably missed the . after import("") as that is needed to trigger the completions?

[MikeMcC399]

Yes, you're absolutely right

import("").

with a period is necessary. Then the issue is reproducible.

Also an important point is that it starts evaluating immediately the period . is typed. It does not require Enter.

[ljharb]

the same would be true if you did new Promise(() => {})., I suspect - iow, i'd guess the repl is automatically blocking on the result of the promise, and import('') never resolves.

[BlankParticle]

I tried to find other cases where this same issue occurs, but looks like only import is the one with this issue

i'd guess the repl is automatically blocking on the result of the promise, and import('') never resolves.

I think this is not true, I am suspecting that the import("") rejects as per the error message about Error: Cannot find package , this is unhandled, somehow this causes to trigger the completions again which tries to import again and we get stuck in a loop

[BlankParticle]

I looked through this and from what I understand, import("") is a ImportExpression node in the AST tree, and its allowed through speculative evaluation.
https://github.com/nodejs/node/blob/main/lib/internal/repl/completion.js#L628-L634
I think the easiest way to fix this is disallow ImportExpression in this list

 acornWalk.simple(lastBodyStatement, {
   ForInStatement: disallow,
   ForOfStatement: disallow,
   CallExpression: disallow,
   AssignmentExpression: disallow,
   UpdateExpression: disallow,
+  ImportExpression: disallow,
 });

this will fix this issue, but you will loose this completion

I think its pretty worth it as import() returns a promise and there is nothing useful to autocomplete on the promise, also (await import("fs")). doesn't work anyways, so we can easily disallow ImportExpression without anything to lose.

Edit: here is a patch, will PR this if this is fine BlankParticle@4e76b75