Adding Expand / Collapse buttons to Experience Editor (Sitecore 9)

ExpanderCollapser.js

/* Adds Expand all and Collapse all buttons to Content Editor */
scContentEditor.prototype.onDomReady = function (evt) {
    this.addCollapser(window.jQuery || window.$sc);
};
scContentEditor.prototype.addCollapser = function ($) {
    $ = $ || window.jQuery || window.$sc;
    if (!$) { return; }

    $('#EditorTabs').append("<style>.toggler { border: 1px solid #bdbdbd; box-shadow: 0 1px #ffffff inset; cursor: pointer; height: 35px; margin: 16px 1px 0; }</style>");
    $('#EditorTabs').append("<button id='expander' class='toggler'>Expand all</button><button id='collapser' class='toggler'>Collapse all</button>");
    $('#EditorTabs').on("click", "#collapser", function () {

        $('.scEditorSectionCaptionExpanded').each(function () {
            var script = $(this).attr("onclick");
            eval(script);
        });
        return false;
    });
    $('#EditorTabs').on("click", "#expander", function () {

        $('.scEditorSectionCaptionCollapsed').each(function () {
            var script = $(this).attr("onclick");
            eval(script);
        });
        return false;
    });
};

ExpanderCollapser.ps1

$file2 = Get-Content "ExpanderCollapser.js"
Add-Content "C:\inetpub\wwwroot\Platform.dev.local\sitecore\shell\Applications\Content Manager\Content Editor.js" $file2