VSCodium and Open VSX Registry: Extension Compatibility for Proprietary API Checks

Answer to the Core Questions

1. Spoofing product identity?

VSCodium’s build process modifies product.json to set its own productName and productId values. Once the binary is compiled, those values are baked in and cannot be changed at runtime or by a command‑line flag. Therefore, there is no supported way for VSCodium to impersonate the official Microsoft VS Code product for extensions that perform a hard check on vscode.env.product or vscode.env.appName.

2. Keeping extensions stable when the core jumps?

The most reliable strategy is to keep the VSCodium core version aligned with the upstream VS Code release it is based on, and to test extensions against that exact version before publishing or upgrading. If an extension contains a proprietary check, the only practical fix is to patch the extension locally (or its package.json) to remove or relax the check, rebuild it, and publish to a local Open VSX registry or the official registry if licensing permits.

Practical Verification Steps

1. Check the core version:

   vscodium --version
   

   The output will show the VSCodium version number, which corresponds to a specific VS Code release (e.g., 1.94.0).
2. Inspect product identity at runtime:

   // In the VSCodium developer console (Help → Toggle Developer Tools)
   console.log(vscode.env.product);
   

   You should see an object with productName: "VSCodium" and a unique productId.
3. Test a suspect extension:
   1. Install the extension from the Open VSX registry.
   2. Open the Output panel, select Extension Host, and look for any error mentioning a product check.
4. Patch an extension (if allowed by license):
   1. Clone the extension’s source or copy its package.json into a local folder.
   2. Remove or modify the code that does something like:

      if (process.env.VSCODE_CLI) { /* check product name */ }
      

   3. Rebuild the extension:

      npm install
      npm run compile
      npx vsce package
      

   4. Publish the patched extension to a local VSX registry or install the .vsix file directly.

Recommended Workflow for Major Core Updates

• Identify the target VS Code release that VSCodium will align with.
• Pull the corresponding VS Code source and build VSCodium (or use the prebuilt release if available).
• Run the verification steps above to confirm the product identity.
• Run a full extension compatibility matrix: install each extension you rely on and check the Extension Host logs.
• If an extension fails due to a product check, decide between:
  • Contacting the extension author for a patch or a new release that removes the check.
  • Locally patching the extension if the license permits.
• Document any changes and keep a changelog of the core version and patched extensions.

Question for Further Clarification

Could you confirm which VS Code core version your current VSCodium build is based on? Knowing the exact baseline will help tailor the patching or upgrade strategy more precisely.