Fix "Run Tests Multiple Times" on Linux

[plemarquand]

Description

When we process the ...args passed to the 'run multiple' commands we're only checking if the argument is an object before deeming it a TestItem.

On linux VS Code is passing an event object like { preserveFocus: true }, which is being treated as a TestItem and causing the command to error out.

Tasks

• Required tests have been written
• Documentation has been updated
• Added an entry to CHANGELOG.md if applicable

[matthewbastien]

Looks good! Just one nitpick.

[matthewbastien]

nit: Would it make sense to also update the function signature to accept ...args: unknown[] just to make it more clear what's going on here? Could even pull out this check into a utility function that we could use later. For example:

function isVSCodeTestItem(obj: unknown): obj is vscode.TestItem {
    return typeof obj === "object"
        && Object.prototype.hasOwnProperty.call(arg, "id")
        && Object.prototype.hasOwnProperty.call(arg, "uri");
}

export function extractTestItemsAndCount(...args: unknown[]): {
    // ...
    if (isVSCodeTestItem(arg)) {
        result.testItems.push(arg);
    }
    // ...
}