special characters (<,>,&) not rendered correctly in intellisense preview

[sandy081]

We used backtick-enclosed strings for types and since everything is escaped now to render a custom hover window, the error messages are illegible now, for example:

current output

note: expected type std::option::Option<std::string::String> found type std::option::Option<&std::string::String>

previous output

note: expected type std::option::Option<std::string::String> found type std::option::Option<&std::string::String>

Ref - rust-lang/vscode-rust#479
Regression from #62370

[sandy081]

@jrieken I was assuming we do not support markdown strings in diagnostic message? Was it leaking somehow before?

[jrieken]

I was assuming we do not support markdown strings in diagnostic message?

Is this really a diagnostic message and not just a hover?

[sandy081]

It is a diagnostic message like follow

const message = "`std::option::Option<&std::string::String>`";

[hokein]

I encountered this issue (VSCode 1.30.1 ) as well:

1. The C++ LSP server (clangd) sends the hover content Declared in function main\n\nstd::vector<std::string> s to vscode
2. The hover dialog renders the content like below, the <> around std::string is missing

[sandy081]

Ok, I see the issue. It is because, I am rendering the diagnostic message as markdown and I am escaping the string only for html content. Strangely markdown renderer is not rendering markdown tags always but only some times. For example

"`std::option::Option<&std::string::String>`"

Markdown tag (tick) is not considered in above case where as it is in following

"this is new line\n\n`std::option::Option<&std::string::String>`"

[sandy081]

Analysis

In order to have nice hover for a diagnostic, I was generating the html and sending it using markdown string. While doing this, I am escaping the message, but the markdown tags are not escaped and they are getting rendered.

Fix

Quick and safe fix is to revert the above change.

The proper fix would be is to move diagnostic hover rendering as an editor contribution. Otherwise, it is quiet impossible to generate a model hover decoration for a diagnostic that shows message and details (source+code) nicely as I can only provide string or markdown string.

[mjbvz]

@sandy081 I just tested this in 61122f8 with the following extension:

import * as vscode from 'vscode';

export function activate(context: vscode.ExtensionContext) {
    vscode.languages.registerHoverProvider('markdown', new Provider())
}

class Provider implements vscode.HoverProvider {
    provideHover(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken): vscode.ProviderResult<vscode.Hover> {
        return new vscode.Hover("std::option::Option<std::string::String> found type std::option::Option<&std::string::String>");
    }
}

I still see the content being treated as markdown:

[sandy081]

Fix is for Diagnostic messages and not for hover providers. Please verify using a diagnostic provider.

'use strict';
import * as vscode from 'vscode';

export function activate(context: vscode.ExtensionContext) {

    const diagnosticsCollection = vscode.languages.createDiagnosticCollection('test');
    vscode.window.onDidChangeActiveTextEditor(e => {
        if (e && e.document) {
            const diagnostics: vscode.Diagnostic[] = [];
            let message = "std::option::Option<std::string::String> found type std::option::Option<&std::string::String>";
            const diagnostic = new vscode.Diagnostic(new vscode.Range(new vscode.Position(10, 1), new vscode.Position(10, 10)), message, vscode.DiagnosticSeverity.Error);
            diagnostic.source = 'test';
            diagnostic.code = 'something';
            diagnostics.push(diagnostic);
            diagnosticsCollection.set(e.document.uri, diagnostics);
        }
    });


}


// this method is called when your extension is deactivated
export function deactivate() {
}

[joaomoreno]

LGTM