Repository navigation
babel-register doesn't save modules to cache properly #9320
Description
Activity
Hey @jbasrai! We really appreciate you taking the time to report an issue. The collaborators
on this project attempt to help as many people as possible, but we're a limited number of volunteers,
so it's possible this won't be addressed swiftly.If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack
community that typically always has someone willing to help. You can sign-up here
for an invite.This does the trick for me:
process.on('SIGINT', () => { console.log('Received Control-C') })
I'm on macOS 10.12.3 with Node v11.6.0
The relevant Node v11.x docs say that the signal event given upon Control-C is SIGINT which is non-Windows. The necessary solution may include something like this for Windows and non-Windows operating systems:
function handle(signal: string): void { console.log(signal) //=> Either 'SIGINT' or 'SIGTERM' } process.on('SIGINT', handle) process.on('SIGTERM', handle)
The
process.on('exit', fn)only seems to be good for when the script is exited on it's own accord.Okay, @jbasrai, I cloned your repo, ran
yarn install, and added the following lines tonode_modules/@babel/register/lib/cache.js:process.on("exit", save); process.on("SIGINT", save); // here process.on("SIGTERM", save); // and here
Then I ran
$ node index.jsand got the following output:hello world . . .And there's a bunch of
^Cand^D's in my output from spamming Control-C and Control-D to try and exit the script (then you have to press Control-Z to move the script to the background and regain control of the terminal, then use$ kill %%or close the terminal to actually stop the script from running).I think the problem is that the
save()function in @babel/register doesn't listen for the signal provided by the nodejs process signal events API.Node v8.x Process Signal Events Docs.
What I've found solves the problem is that if
save()accepted asignalargument and checked forsignal === "SIGINT"then we canprocess.exit(2)just like the native behavior (at least on macOS).function save(signal) { if (signal === "SIGINT") { console.log("Received Control-C"); process.exit(2); } let serialised = "{}"; // Rest of body code, etc... }
Someone should test this on a Windows box to see if we need to check for SIGTERM as well (
signal === "SIGINT" || singal === "SIGTERM"may be necessary).Hope this is helpful.
Reacted by Huáng Jùnliàng@chrisisler Could you open up a PR to have
save()listen forSIGINTandSIGTERM?@JLHwung I think it would also be good to call a debounced
savefunction anytime the in-memory cache is updated.But beyond this, I think it would be better to save each input file's transformed code and source maps in individual files within a cache directory so that tasks which only load a small number of modules in a large codebase don't have to load one giant JSON file into memory
@jedwards1211 #17229 should fix it.
Reacted by Andy Edwards- locked as resolved and limited conversation to collaborators
on May 2, 2026
Bug Report
Current Behavior
For scripts that don't exit the event loop (e.g. an express server), modules that are loaded outside of the original script don't get cached.
Input Code
Minimal repro here: https://github.com/jbasrai/babel-register-cache
yarnnode index.jsExpected behavior/code
Expected
world.jsto be cached, but inspecting the cache reveals that it isn't.Babel Configuration (.babelrc, package.json, cli command)
Environment
registerPossible Solution
The
process.on('exit')listener is not being used correctly. The docs say that it is only called whenprocess.exit()is called explicitly OR when Node's event loop no longer has work to perform. In the above case, none of these conditions are met, and so a required module is never cached.Instead, I think a more comprehensive exit handler should be used to save the cache.