check for host before .substring

[davehorner]

I think that substring should be checked. if host is not passed, it shouldn't deref a null. if host isn't passed, it should work right?
using import * as scrawl from "https://unpkg.com/[email protected]";

Exported function (to modules and scrawl object). Use addCanvas to add a Scrawl-canvas canvas element to a web page. The items argument should include

host - the host element, either as the DOM element itself, or some sort of CSS search string, or a Scrawl-canvas Stack entity. If no host is supplied, Scrawl-canvas will add the new canvas element to the DOM document body; in all cases, the new canvas element is appended at the end of the host element (or DOM document)
name - String identifier for the element; will generate a random name for the canvas if no name is supplied.
any other regular Scrawl-canvas Canvas artefact attribute
By default, Scrawl-canvas will setup the new Canvas as the ‘current canvas’, and will add mouse/pointer tracking functionality to it. If no dimensions are supplied then the Canvas will default to 300px wide and 150px high.

export const addCanvas = function (items = Ωempty) {
...
    if (host.substring) {  <-- **YOU USE HOST WITHOUT CHECKING HOST IS NOT NULL**

        temphost = artefact[host];

        if (!temphost && host) {

            host = document.querySelector(host);

            if (host) mygroup = host.id;
        }
        else host = temphost;
    }

    if (host) {  <--- **YOU CHECK FOR HOST HERE.**

        if (host.type === T_STACK) {

            mygroup = host.name;
            position = ABSOLUTE;
            host = host.domElement;
        }
        else if (!isa_dom(host)) host = document.body;
    }
    else host = document.body;
...
};

#127
if (host && host.substring)