How to properly update workspace when a dsl file is renamed ?

[ydaveluy]

Hello,

I have a file a.mydsl that defines types and a second file b.mydsl with references to types defined in a.mydsl. If I rename a.mydsl to an extension not handled by my language such as a.mydsl.old, the file b.mydsl remains valid.
I have to restart VSCode to have invalid references in b.mydsl.

It seems that Langium keeps a document in the index in case the file extension is changed and not supported by the language.
Deletion works well, if I remove a.mydsl, b.mydsl is correctly updated.

[ydaveluy]

When a.mydsl is renamed to a.mydsl.old, it calls first DefaultDocumentUpdateHandler.didChangeContent() then DefaultDocumentUpdateHandler.fireDocumentUpdate().

I think that the incorrect behavior comes from DefaultServiceRegistry.hasServices() that returns true for uri a.mydsl.old.

Maybe that an other interface such as ServiceRegistry.hasValidFileExtension(uri:URI) would be more appropriate ?

[msujew]

Hey @ydaveluy,

This is intended behavior (at least in VS Code). See also #1492 which contains links to a discussion surrounding this issue. In the end, we only listen to what the language client tells us.

In VS Code, if you rename a file extension to something that doesn't have a language associated with it, it will keep the old language association. You will see that the renamed file keeps the same language id (in the status bar). We correctly identify that by taking a look at the text document provided by the language client.

You can disable that behavior by overriding the ServiceRegistry. I wouldn't recommend it though, because this already works exactly how it's supposed to work.

[ydaveluy]

Ok thanks for the recommendation :-)