Importing random in Javascript causes a ReferenceError in Node

[ziotom78]

Importing random and exporting to a Javascript file produces a ReferenceError when ran by Node.

Example

import random

echo "Hello, world!"

Current Output

Hint: used config file '/home/tomasi/Projects/Nim/config/nim.cfg' [Conf]
Hint: used config file '/home/tomasi/Projects/Nim/config/config.nims' [Conf]
...................
/home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.nim(1, 8) Warning: imported and not used: 'random' [UnusedImport]
Hint: 32869 lines; 0.376s; 39.891MiB peakmem; Debug build; proj: /home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.nim; out: /home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.js [SuccessX]
Hint: /usr/bin/node /home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.js  [Exec]
/home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.js:2506
if (globalThis.utcInstance_603981990 === undefined) {
^

ReferenceError: globalThis is not defined
    at Object.<anonymous> (/home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.js:2506:1)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:623:3)
Error: execution of an external program failed: '/usr/bin/node /home/tomasi/Documents/corsi/ray-tracing/performance-tests/intersect.nim/test.js '

Expected Output

Hello World!

Possible Solution

• Removing import random solves the issue. However, in the script I am developing, I need to use random.

Additional Information

This happens with both the master Nim branch and with release 1.4.2.

$ /home/tomasi/Projects/Nim/bin/nim --version
Nim Compiler Version 1.5.1 [Linux: amd64]
Compiled at 2020-12-16
Copyright (c) 2006-2020 by Andreas Rumpf

git hash: 9ef7c0182058141b81a41e32b699be8f2e42f3e9
active boot switches: -d:release

I see there have been some issues with random+JS in the past (#12418, #11772, #9999), but they seem unrelated, as the error there was an overflow.

[timotheecour]

can't reproduce

• also tried with: XDG_CONFIG_HOME= nim r -b:js --eval:'import random; echo 1' to avoid my user config
• also tried with -d:nodejs
• and with provided hash 9ef7c0182058141b81a41e32b699be8f2e42f3e9 and 1.4.2

node -v
v14.7.0

on osx.

what is node -v for you?

[ziotom78]

I am using Linux Mint 20 and have installed node using apt. The version provided by Mint is the same as Ubuntu 20.04, which is older than yours:

$ node -v
v10.19.0

$ apt-cache show nodejs
Package: nodejs
Architecture: amd64
Version: 10.19.0~dfsg-3ubuntu1
Multi-Arch: foreign
Priority: extra
Section: universe/web
Origin: Ubuntu
Maintainer: Ubuntu Developers <[email protected]>
Original-Maintainer: Debian Javascript Maintainers <[email protected]>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 154
Depends: libc6 (>= 2.4), libnode64 (= 10.19.0~dfsg-3ubuntu1)
Recommends: ca-certificates, nodejs-doc
Suggests: npm
Conflicts: nodejs-legacy
Replaces: nodejs-legacy
Filename: pool/universe/n/nodejs/nodejs_10.19.0~dfsg-3ubuntu1_amd64.deb
Size: 61128
MD5sum: e99245e2f78b02e736f6585be7a200f2
SHA1: 8a7f18fc393650d3f0830c6cde0e0bfa7e4afa17
SHA256: 392d4ae36ca956260df71b43f7cd04c1f8928dac5e53f4132d237772b16adf4a
Homepage: http://nodejs.org/
Description-en: evented I/O for V8 javascript - runtime executable
 Node.js is a platform built on Chrome's JavaScript runtime for easily
 building fast, scalable network applications. Node.js uses an
 event-driven, non-blocking I/O model that makes it lightweight and
 efficient, perfect for data-intensive real-time applications that run
 across distributed devices.
 .
 Node.js is bundled with several useful libraries to handle server
 tasks:
 .
 System, Events, Standard I/O, Modules, Timers, Child Processes, POSIX,
 HTTP, Multipart Parsing, TCP, DNS, Assert, Path, URL, Query Strings.
Description-md5: 0d0bbaed314d7d26588d112ee4ede074

[ziotom78]

Following your suggestion, I downloaded the most recent version of node (14.15.2) and the problem disappeared. Fantastic!

It seems that the globalThis symbol causing the error was introduced in Node 12 (https://blog.logrocket.com/what-is-globalthis-why-use-it/).

From my side, this issue can be closed. However, I expect that other Ubuntu/Mint users might stumble upon this problem.

[timotheecour]

maybe this could be documented somehow

[ziotom78]

maybe this could be documented somehow

Should I open a new issue, or is it better to reopen this?

[timotheecour]

PR would be best

[ziotom78]

Ok, but please give me an hint where to document this. My idea is to put the information in the page

https://nim-lang.org/docs/backends.html#backends-the-javascript-target

Would it be fine, or is there a better place where to place it?

[timotheecour]

yes, there (backends.rst); maybe simply add a line in the appropriate place indicating if you have error such and such, make sure your node version is recent enough (e.g. >= ...)