vscode.workspace.workspaceFolders[0].uri.fsPath running an error called object is undefined?

Question

I was developing VS code extension and try to create and add files/folders into the workspace. But there was an error came up "Object is possibly 'undefined'.ts(2532)". I am using latest typescript version which is "typescript": "^4.5.4". here's the code.

Error line: const projectRoot = vscode.workspace.workspaceFolders[0].uri.fsPath;

createFileOrFolder(taskType: 'file' | 'folder', relativePath?: string) { relativePath = relativePath || '/'; 

        const projectRoot = vscode.workspace.workspaceFolders[0].uri.fsPath; // here's the error "Object is possibly 'undefined'.ts(2532)"
       

        if (path.resolve(relativePath) === relativePath)
            relativePath = relativePath.substring(projectRoot.length).replace(/\\/g, "/");

        if (!relativePath.endsWith("/")) relativePath += '/';
        const basepath = projectRoot;

        vscode.window.showInputBox({
            value: relativePath || '/',
            prompt: `Create New ${taskType} (/path/subpath/to/${taskType})`,
            ignoreFocusOut: true,
            valueSelection: [-1, -1]
        }).then((fullpath) => {
            if (!fullpath) return;
            try {
                let paths = fullpath.split('>').map(e => e.trim());
                let targetpath = taskType === 'file' ? path.dirname(paths[0]) : paths[0];
                paths[0] = taskType === 'file' ? path.basename(paths[0]) : '/';
                targetpath = path.join(basepath, targetpath);
                paths = paths.map(e => path.join(targetpath, e));

                if (taskType === 'file')
                    this.makefiles(paths);
                else
                    this.makefolders(paths);



                setTimeout(() => { //tiny delay
                    if (taskType === 'file') {
                        let openPath = paths.find(path => fs.lstatSync(path).isFile())
                        if (!openPath) return;
                        vscode.workspace.openTextDocument(openPath)
                            .then((editor) => {
                                if (!editor) return;
                                vscode.window.showTextDocument(editor);
                            });
                    }
                }, 50);
            } catch (error) {
                this.logError(error);
            }

        });
    } 

Can anyone help me out to fix this problem?

Answer 1

This happens because workspaceFolders is defined as:

    export const workspaceFolders: readonly WorkspaceFolder[] | undefined;

Which means it can be undefined.

The reason: if you don't have any workspace open in VS Code, like an empty window or just single/random files, workspaceFolders property won't be defined.

Your code must handle that situation, probably quiting/displaying a message on these scenarios

Something like:

    if (!vscode.workspace.workspaceFolders) {
        vscode.window.showInformationMessage("Open a folder/workspace first");
        return;
    }