Complex path leads to unresolved cross reference despite working scoping

[antoinelilly]

Hello all!

I'm finding myself facing a problem, but my grammar is getting really complex, so I will try to explain it as clearly as possible.

I'm using the DocumentBuilder to generate AstNodes from my files and navigating through them via cross references. My files show no validation error, and my scoping works so I expect that none of my references should be unresolved in the AstNodes I get from the DocumentBuilder. Here is how I build my AstNodes :

let files: string[] = // an array with all the paths to my files
let models: Model[] = []

let MyDocuments:LangiumDocument<AstNode>[];
let documentsPromise: Promise<LangiumDocument<AstNode>>[] = files.map(file => 
    this.services.shared.workspace.LangiumDocuments.getOrCreateDocument(URI.file(path.resolve(file)))
);
MyDocuments = await Promise.all(documentsPromise);

await Promise.all(documents.map(async (document: LangiumDocument) => {
    await this.services.shared.workspace.DocumentBuilder.build([document], { validation: true });
    let _a: ParseResult = document.parseResult;
    models.push(_a.value as Model)

}));

This works fine, I build the AstNodes. In my language I call the entry Model. However, while trying to access a specific complex path, i get an unresolved reference. The following path is correct based on my language AST:

let refEntity = property.call.to.ref?.entity.ref?.name

This returns undefined which is not what I expect. In this specific case, I navigate through several cross-reference and the last one is a cross reference to an AstNode in another Model than the Model containing the property node. Trying to log : property.call.to.ref?.entity returns the error message Could not resolve reference to RefType named 'SiteProductFormGroup'.. RefType is the correct type, and the name is also correct.

What confuses me the most is that I can access other nodes from different Models by following other paths and cross references. This one is the only one that returns undefined.

I have no idea what I do wrong here. Is there a limit of cross references I can access in my Model AstNode? Or do I misunderstand how global scoping works when using the DocumentBuilder? I will appreciate any help or lead to find the answer.

Thank you!

[msujew]

Hey @antoinelilly,

So generally, it should not matter how many references you attempt to resolve in a single expression chain. In fact, since you run the full document builder beforehand, each reference is resolved first independently and then cached. When accessing the ref value, you're actually just accessing that cached value.

As for the error: I'm actually not entirely sure what could be the issue here. I would need a reproducible example for that. One thing that can be improved in your code is to execute the document builder only once with all documents (that's why the document builder accepts an array). However, that shouldn't influence the behavior of the linking, it's only a performance optimization. You might want to try that anyway.

Given that all the other references resolve correctly, I'm inclined to think that this might be a minor error in your linking/scoping code. I would recommend to isolate the DSL snippet and write a test to try to reproduce and then debug everything.

[antoinelilly]

Hello @msujew!

Surprisingly, I took your advice to improve my code with the DocumentBuilder and it completely fixed the problem. I'm guessing maybe it did influence the behavior of the linking?

Thank you for your insight!