test.js

function getSnippet(snippetName, snippetFormat) {

    var serviceURL = "@Url.Action("Content", "Snippets")";

    console.log(snippetName);

    $.ajax({
        type: "POST",
        url: serviceURL,
        data: {
            name: snippetName,
            format: snippetFormat
        },
        success: successFunc,
        error: errorFunc
    });

    function successFunc(data, status) {
        if (snippetFormat == "HTM")
            document.querySelector('[tx-snippet-name="' + snippetName + '"] .snippet-preview').innerHTML = data + "...";
        else
            TXTextControl.selection.load(TXTextControl.StreamType.InternalUnicodeFormat, data);
    }

    function errorFunc() {
        $("#myToast .toast-body").text("Error! :-(");
        $("#myToast").toast("show");
    }
}