Proposal: Enforce protectedFiles at extension host file system layer

[Baby-adi]

Proposal: Enforce protectedFiles at extension host file system layer

Background

There is currently no mechanism in the extension host layer to prevent programmatic reads of sensitive files (e.g. .env) by extensions.

An initial PR implemented workspace.protectedFiles to disable inline suggestions for protected files. However, extending this to block workspace.fs.readFile requires access to configuration within ExtHostFileSystem.

Architectural Constraint

ExtHostFileSystem does not currently have access to configuration services. Injecting configuration requires modifying constructor wiring in extHost.api.impl.ts, which becomes an architectural change rather than a localized patch.

Proposal

Introduce a supported way for ExtHostFileSystem to query configuration (e.g. via ExtHostConfiguration) to allow enforcement of:

• Programmatic read blocking
• Potential future write blocking

Question

Would maintainers prefer:

1. Injecting configuration into ExtHostFileSystem
2. Centralizing protected file enforcement elsewhere in extension host
3. A different approach entirely

Happy to iterate based on architectural guidance.