Issues with polyfills in extensions

[remojansen]

The official vscode python extension recently experimented some issues caused by a polyfill.

The polyfill is the reflect-metadata module. This module overrides the Reflect global object. Every time the reflect-metadata is imported, the Reflect global is overwritten. This is a problem because this global object allows us to define metadata and it contains an internal WeakMap that stores the metadata. When the global is overwritten, the WeapMap is also overwritten and all the metadata is deleted.

If two extensions import reflect-metadata, one will remove the metadata created by the other.

We can fix this by changing the polyfill (reflect-metadata) source code but if some extension is using an outdated version or some extension is using a different polyfill we will have the same problem.

So I was wondering if it is possible for the vscode extensions runtime to isolate the globals between extensions? or prevent polyfill-related issues?

cc: @DonJayamanne

[vscodebot]

This issue is caused by an extension, please file it with the repository (or contact) the extension has linked in its overview in VS Code or the marketplace for VS Code. See also our issue reporting guidelines.

Happy Coding!

[jrieken]

So I was wondering if it is possible for the vscode extensions runtime to isolate the globals between extensions?

The idea is cool but I am afraid it's too late for that. We don't know what extensions/node_modules actually depend on something like that and we wouldn't wanna break them... The only option we have to fix this at the source, e.g at reflect-metadata

[remojansen]

@jrieken thanks for the help. Will see if I can try to get a fix merged into reflect-metadata.

[remojansen]

The issue in reflect-metadata has been fixed. More info at inversify/InversifyJS#737 (comment)