old_contents: /**
   * Client tests
   */
  import React from "react";
  import { renderIntoDocument, findRenderedDOMComponentWithClass,
    createRenderer } from "react-addons-test-utils";
  import Component from "src/components/playground";
  
  describe("components/playground", function () {
  
    it("has expected content with deep render", function () {
      // This is a "deep" render that renders children + all into an actual
      // browser DOM node.
      //
      // https://facebook.github.io/react/docs/test-utils.html#renderintodocument
      const rendered = renderIntoDocument(<Component />);
  
      // This is a real DOM node to assert on.
      const divNode = findRenderedDOMComponentWithClass(rendered, "playgroundCode");
      expect(divNode).to.not.be.undefined; //eslint-disable-line no-unused-expressions
    });
  
    it("has expected content with shallow render", function () {
      // This is a "shallow" render that renders only the current component
      // without using the actual DOM.
      //
      // https://facebook.github.io/react/docs/test-utils.html#shallow-rendering
      const renderer = createRenderer();
      renderer.render(<Component />);
      const output = renderer.getRenderOutput();
      expect(output.type).to.equal("div");
    });
  });
  
new_contents: /**
   * Client tests
   */
  import React from "react";
  import { renderIntoDocument, findRenderedDOMComponentWithClass,
    createRenderer } from "react-addons-test-utils";
  import Component from "../../../src/components/playground";
  
  describe("components/playground", function () {
  
    it("has expected content with deep render", function () {
      // This is a "deep" render that renders children + all into an actual
      // browser DOM node.
      //
      // https://facebook.github.io/react/docs/test-utils.html#renderintodocument
      const rendered = renderIntoDocument(<Component />);
  
      // This is a real DOM node to assert on.
      const divNode = findRenderedDOMComponentWithClass(rendered, "playgroundCode");
      expect(divNode).to.not.be.undefined; //eslint-disable-line no-unused-expressions
    });
  
    it("has expected content with shallow render", function () {
      // This is a "shallow" render that renders only the current component
      // without using the actual DOM.
      //
      // https://facebook.github.io/react/docs/test-utils.html#shallow-rendering
      const renderer = createRenderer();
      renderer.render(<Component />);
      const output = renderer.getRenderOutput();
      expect(output.type).to.equal("div");
    });
  });
  
subject: fix component import path