VS Code Auto Completion Does Not Work for Theia Symbols

[AidarZayn]

Question

Hello,

I am currently learning Eclipse Theia and have encountered an issue with auto-completion in VS Code while developing custom extensions.

The problem can be reproduced both in:

• the Theia repository cloned from GitHub;
• a project generated using the Yeoman Generator.

For example, in the file:

src/browser/my-extension-backend-contribution.ts

I start typing:

export class MyContribution implements BackendApplicationContribu/* cursor */ {}

or other commonly used symbols such as:

• BackendApplicationContribution
• injectable
• inject
• ContainerModule

However, after pressing Ctrl+Space, VS Code does not suggest these symbols and does not perform auto-imports.

At the same time, TypeScript resolves everything correctly when imports are added manually.

For example:

import {} from '@theia/core/lib/node';

VS Code shows the list of exported symbols, including BackendApplicationContribution.

So the issue appears to be specifically related to auto-completion / auto-import for symbols exported by Theia packages.

Is this a known limitation of the Theia API (for example, due to deep imports such as @theia/core/lib/node), a TypeScript/VS Code configuration issue, or am I missing some project setup step?

Any guidance would be appreciated.

[github-actions[bot]]

Hi @AidarZayn, thanks for starting this discussion! 👋

The Theia community will take a look soon. In the meantime, you might find helpful information in:

• 📖 Theia Documentation
• ❓ FAQ
• 💬 Previous Discussions

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[ndoschek]

Hi @AidarZayn,

This is expected, and it's a VS Code/TypeScript behavior rather than a Theia issue. Theia packages declare "main": "lib/common/index.js", and platform-specific code lives behind deep subpath imports like @theia/core/lib/node or @theia/core/lib/browser on purpose (so browser code can't accidentally import node code, see doc/code-organization.md).

VS Code's auto-import only indexes what's reachable from the main entry, so symbols like BackendApplicationContribution, injectable, etc. don't surface via Ctrl+Space. Once you type the import path yourself (e.g. import { } from '@theia/core/lib/node';), IntelliSense lists everything as expected.

HTH