Code extension registers multiple providers for the rust-analyzer scheme

[lnicola]

From the registerTextDocumentContentProvider docs: "Only one provider can be registered per scheme".

Two of the providers appear to handle this correctly (rust-analyzer-status, rust-analyzer-memory), we should probably do the same thing in the remaining four places.

CC eclipse-theia/theia#9136 (comment)

[yongikim]

@lnicola Hello. I'm looking for a "good-first-issue" to work on. Can I work on this issue? Is it fixed by #12702?

[lnicola]

It's not fixed yet. Originally:

• every custom command returning (we have a couple of them) a file used the same scheme
• every invocation of a custom command registered the same scheme again

#12702 fixed the first problem, the second still exists. To fix this you'll probably have to extract the registerTextDocumentContentProvider calls out of the commands and run them only once, the extension initialization.

[yongikim]

Thank you. I'll try it. It may take a little while because this is my first time to develop a vscode extension.

[yongikim]

I cannot reproduce the issue. Here are what I did to debug:

1. Open editors/code/src/commands.ts in vscode.
2. Add some console.logs in viewItemTree function:

export function viewItemTree(ctx: Ctx): Cmd {
    // ...

    console.log("viewitem"); // I added this line.
    ctx.pushCleanup(
        vscode.workspace.registerTextDocumentContentProvider("rust-analyzer-item-tree", tdcp)
    );

    return async () => {
        console.log("viewitem async"); // I added this line.
        // ...
    }
}

3. Run the extension in the Extension Development Host window of the vscode and run rust-analyzer: Debug ItemTree command three times.
4. Debug console of the original vscode window is as follows:

Probably I'm wrong but It appears that registerTextDocumentContentProvider is called only once at the extension initialization and when the custom command is invoked afterwards, the returned funciton by viewItemTree is called.

[lnicola]

Yes, I think you're right. Sorry for the inconvenience :(.