Activating extension failed: Must use import to load ES Module

[laike9m]

Describe the bug

When my extension is being activated, it reports the following error

Activating extension 'Cyberbrain' failed: Must use import to load ES Module:
 /tmp/vscode-extensions/[email protected]/extension/out/extension.js require()
 of ES modules is not supported. require()
 of /tmp/vscode-extensions/[email protected]/extension/out/extension.js from
 /theia/node_modules/@theia/plugin-ext/lib/hosted/node/plugin-host-rpc.js is an ES module
 file as it is a .js file whose nearest parent package.json contains
 "type": "module" which defines all .js files in that package scope as ES modules.

 Instead rename extension.js to end in .cjs, change the requiring code to use import(),
 or remove "type": "module" from /tmp/vscode-extensions/[email protected]/extension/package.json.

The same extension can work in VS Code without any problem, and it used to (around two weeks ago) work in Gitpod as well.

Steps to reproduce

Visit
https://gitpod.io/#snapshot/91475a9d-4ccf-420a-b0ee-11db084ce689
and you'll see the error popup.

Expected behavior

The extension can be activated successfully with no error.

Additional information

Example repository

Repository of my extension:
https://github.com/laike9m/Cyberbrain/tree/master/cyberbrain-vsc

[akosyakov]

It could be related to Node.js version which we are using to deploy Theia: manuelbieh/geolib#208 We switched to Node.js 12.18.3 in last release. Latest VS Code is 12.14.1.

[laike9m]

This looks like my issue, but I do need the "type": "module". Any ideas?

[akosyakov]

Yes removing it will fix the issue. I think the following is happening:

• in 12.14.1 ES modules are experimental and not enabled by deafult, it is why it works in VS Code
• in 12.18.3 is already LTS and ES modules are not experimental anymore, so Node will try to respect "type": "module". It is why it does not work for you in Gitpod, as soon as VS Code moves to newer Node.js your extension will have such problem there as well.

[akosyakov]

but it could be a good idea for us to downgrade Node.js to avoid such issues for extensions

[laike9m]

By downgrade you mean? My understanding is that the Node.js version is controlled by VS Code, so once it decides to upgrade my extension will break. Or is it?

[akosyakov]

By downgrade you mean? My understanding is that the Node.js version is controlled by VS Code, so once it decide to upgrade my extension will break. Or is it?

Sorry for the confusion. I meant downgrading Node.js version in Gitpod that all VS Code extensions which working in VS Code now also work in Gitpod.

I think you just should remove "type": "module" now from package.json and deploy a new version.

[laike9m]

Got it. To me it seems to makes more sense if Gitpod can keep the Node version the same with VS Code to avoid such issue from happening. And when VS Code upgrades the Node version (and break my extension potentially), I shall fix it, otherwise it's hard to fix it locally.

[laike9m]

Any thoughts?

[akosyakov]

PR is there: #2508 but I doubt we will deploy it this year, likely beginning next year.

[laike9m]

thanks

[akosyakov]

The fix was deployed.

[laike9m]

VS Code has upgraded the node version to 12.18.3

[akosyakov]

@laike9m thank you for a ping, I will bump it up this month: #3069 (comment)