Fix Substack Gist embedding by pasting this into the console

substack_gist_fixer.js

// source: https://github.com/Maluen/code-medium/issues/11#issuecomment-2192400621
// I am taking it for archival and convenience - I've done no changes
var _open = XMLHttpRequest.prototype.open;
window.XMLHttpRequest.prototype.open = function (method, URL) {
    var _onreadystatechange = this.onreadystatechange,
        _this = this;

    _this.onreadystatechange = function () {
        if (_this.readyState === 4 && _this.status === 200 && ~URL.indexOf('api/v1/github/gist')) {
            try {
                var data = JSON.parse(_this.responseText);

                data.innerHTML = data.innerHTML.replace(/<template ([\s\S]*?)>([\s\S]+?)<\/template>/g, ' ');

                // rewrite responseText
                Object.defineProperty(_this, 'responseText', {
                  value: JSON.stringify(data),
                  configurable: true,
                  enumerable: true,
                });
            } catch (e) {}
        }
        // call original callback
        if (_onreadystatechange) _onreadystatechange.apply(this, arguments);
    };

    // detect any onreadystatechange changing
    Object.defineProperty(this, "onreadystatechange", {
        get: function () {
            return _onreadystatechange;
        },
        set: function (value) {
            _onreadystatechange = value;
        }
    });

    return _open.apply(_this, arguments);
};