Open another document in VSCode extension from Hover

Question

I try to open a document from a Hover in a VSCode Extension.

The Hover appears, the link is shown and also the URI, but when I click, nothing happens. There is an output in the Debug Console, that the command is unknown in the Developer Tools Console.

What I am doing wrong? Here is the code, a little bit simplified

context.subscriptions.push(
        vscode.languages.registerHoverProvider({pattern: '**/*.{ttp,tts}'}, {
            provideHover(document, position, token) {
                
                const linkPosition = new vscode.Position(10, 1);
                const range = new vscode.Range(position, position);
                
                const opts: vscode.TextDocumentShowOptions = {
                    selection: range,
                    viewColumn: vscode.ViewColumn.Beside
                };
                
                const workspace = vscode.workspace.workspaceFolders?.find(e => e.uri.fsPath.endsWith("workspace"));
                const uri = vscode.Uri.file(`${workspace?.uri.path}/_global.tt/ercdata/ttc.properties`);

                const args = [{ uri: uri , options: opts}];  

                const stageCommandUri = vscode.Uri.parse(
                    `command:window.showTextDocument?${encodeURIComponent(JSON.stringify(args))}`
                );
                let link = new vscode.MarkdownString(`[Open...](${stageCommandUri})`);
                link.isTrusted = true;

                let hover: vscode.Hover = {
                    contents: [link]
                };
                return hover;

                let x = properties.getHoverFor(document, position, path.basename(document.uri.fsPath).replace(".tts","").replace(".ttp","").toLowerCase()); 
                return  x;
            }
        }));

Here is how the Hover renders:

Here is the output of the dev console:

Answer 1

You should use a true command like vscode.open as documented in this article , or your own command.

window.showTextDocument alone is an extension API.

Answer 2

Lex Li pointed me into the right direction, thank you.

Wrapping the openTextDocument task into my own command and adressing this command from the Hover solves the problem:

context.subscriptions.push(vscode.commands.registerCommand('estudio.internal.open', (uri: vscode.Uri, options: vscode.TextDocumentShowOptions) => {
            logger.info("Opening a document");
            vscode.window.showTextDocument(uri, options);
        }));

Than composing the Hover use

const stageCommandUri = vscode.Uri.parse(
                    `command:estudio.internal.open?${encodeURIComponent(JSON.stringify(args))}`

did it.