gistfile1.txt

/**
 * isError:
 * @obj (Object): the object to be tested
 * 
 * Tests whether @obj is an error object. If the object
 * is a GLib.Error then we add a stack trace to it.
 *
 * Returns (boolean): whether @obj is an error object
 */
function isError(obj) {
    let isErr = false;
    if (typeof(obj) == 'object' && 'message' in obj && 'stack' in obj) {
        isErr = true;
    } else if (obj instanceof GLib.Error) {
        let stack = Error().stack;
        stack = stack.substr(stack.indexOf('\n') + 1);
        obj.stack = stack;
        isErr = true;
    }
    return isErr;
}