function testOpHtml(browser, opName, input, cssSelector, output, args=[]) {
    bakeOp(browser, opName, input, args);

    if (typeof output === "string") {
        browser.expect.element("#output-html " + cssSelector).text.that.equals(output);
    } else if (output instanceof RegExp) {
        browser.expect.element("#output-html " + cssSelector).text.that.matches(output);
    }
}
@function
Clears the current recipe and tests a new operation with HTML output.

@param {Browser} browser - Nightwatch client
@param {string|Array<string>} opName - name of operation to be tested array for multiple ops
@param {string} input - input text
@param {string} cssSelector - CSS selector for HTML output
@param {string|RegExp} output - expected output
@param {Array<string>|Array<Array<string>>} [args=[]] - arguments, nested if multiple ops