CODEWITHSUNDEEP
node.jsbabeljsbabel-cli
Pavel 'Strajk' Dolecek
Pavel 'Strajk' Dolecek

Reputation: 724

How to pass options to node when using babel-node

Babel CLI docs (https://babeljs.io/docs/usage/cli/):

babel-node [options] [ -e script | script.js ] [arguments]

But when trying to increase allocated memory for Node:

babel-node --max-old-space-size=16384 script.js

argument --max-old-space-size=16384 seems to be ignored

Does sb know if this should work, and if shouldn't - some workaround?

Upvotes: 7

Views: 6525

Answers (4)

Chad
Chad

Reputation: 9859

You can also use an environment variable to bypass babel-node having to support the flag all together.

NODE_OPTIONS=--max-old-space-size=16384 babel-node [options] [ -e script | script.js ] [arguments]

In my case I needed to use --tls-min-v1.0 but babel-node doesnt know that flag.

NODE_OPTIONS=--tls-min-v1.0 did the trick.

Upvotes: 1

Chad
Chad

Reputation: 9859

I am using Babel 7, and this does in fact work.

babel-node --max-old-space-size=16384 script.js

Easy way to test is to just lower the size to 100KB, and you will run out of memory quickly.

Upvotes: 7

FredG
FredG

Reputation: 869

There is a bug maybe related to node v10... v8flags v2 is not working well, you need to use current v8flags 3.1.1.

I'm using yarn for global node tools, here are the quick command to do a quick patch (likely to be redone on each yarl global add)...

If using babel-cli 6 yarn global add v8flags rm -rf ~/.config/yarn/global/node_modules/babel-cli/node_modules/v8flags

You could use babel 7, but there is a lot of change to do in your babel configs yarn global add @babel/core @babel/node

Upvotes: 1

danez
danez

Reputation: 1709

Edit: (Juli 2016) As of version 6.11.4 all variations are supported now. The example posted in the question works now.

Babel in version 6.11.3 does not support all variations of v8Flags yet.

Node itself supports passing this flags either with underscore (--max_old_space_size) or dashes (--max-old-space-size).

In contrast babel-node only supports these flags if the are specified with underscores and does not support the format --flag=value.

There is a open pull request, that addresses this issues. Sadly there is no current workaround for specifying v8Flags with values.

Upvotes: 6

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