How do I get this extension to work with Theia?

[Qichar]

Hello, I am trying to get the scalameta.metals vscode extension to work with Theia (the browser-based vscode like IDE). I started by downloading:

scalameta.metals-1.20.0.vsix

and simply dropping it in the plugins folder. It was recognized by Theia, and when I tried to open a .sc file it attempted to activate the extension. However, I got this error:

root ERROR [hosted-plugin: 4807] Activating extension 'Scala (Metals)' failed: TypeError: Class extends value undefined is not a constructor or null
at Object. (/tmp/vscode-unpacked/scalameta.metals-1.20.0.vsix/extension/node_modules/vscode-languageclient/lib/common/protocolTypeHierarchyItem.js:8:46)
at Module._compile (node:internal/modules/cjs/loader:1155:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1209:10)
at Module.load (node:internal/modules/cjs/loader:1033:32)
at Function.Module._load (node:internal/modules/cjs/loader:868:12)
at Function.module._load (/home/komchang/cse/node_modules/@theia/plugin-ext-vscode/lib/node/plugin-vscode-init.js:68:33)
at Module.require (node:internal/modules/cjs/loader:1057:19)
at require (node:internal/modules/cjs/helpers:103:18)
at Object. (/tmp/vscode-unpacked/scalameta.metals-1.20.0.vsix/extension/node_modules/vscode-languageclient/lib/common/codeConverter.js:18:37)
at Module._compile (node:internal/modules/cjs/loader:1155:14)

I was able to install this extension for use with vscode on my Mac just fine by following the instructions in the Readme.md file. However, it's not working with Theia. Does the "installer" do something special? Every other vscode language extension has worked in Theia for me simply by dropping it into the plugins folder. Does this extension have special setup requirements?

I am using node version 16.18.1. I am using the extension provided by the "releases" section of this github, not one I built myself.

[tgodzik]

Thanks for the question! The last time I tried to use Eclipse Theia it was working mostly alright. What seems weird here is that the error is not in actual code we provide but in the library one. My guess is that we use newer version of vscode-languageclient that is not yet supported by theia?

[tgodzik]

and the extension would not activate at all.

Do you have a stack trace for the issue? Maybe it's something that we can solve?

Does it help if you change the configuration to use code lenses?

[tgodzik]

"metals.testUserInterface": "Code Lenses"

[Qichar]

Hi, thanks again for your help!

The error that prevents activation of 1.11.0 is:

root ERROR [hosted-plugin: 17434] Activating extension 'Scala (Metals)' failed: TypeError: Cannot read properties of undefined (reading 'createTestController')
at new TestManager (/tmp/vscode-unpacked/scalameta.metals-1.12.0.vsix/extension/out/test-explorer/test-manager.js:45:46)
at createTestManager (/tmp/vscode-unpacked/scalameta.metals-1.12.0.vsix/extension/out/test-explorer/test-manager.js:39:12)
at /tmp/vscode-unpacked/scalameta.metals-1.12.0.vsix/extension/out/extension.js:412:66

[tgodzik]

Let's try with #1245

You can test out the change by doing yarn build and then using the resulting vsix.

[tgodzik]

We just merged it, could test it by downloading the latest vsix from https://marketplace.visualstudio.com/items?itemName=scalameta.metals ?