javascript - `render` 在下面的单元测试中做了什么？

Question

下面的代码可以在没有的情况下工作render(tree, answer)吗？它在引擎盖下做了什么？

   // unit tests
    // do not modify the below code
    describe('tests', function() {
      const answer = [ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K' ];

  const tree = {
    value: "A",
    left: {
      value: "B",
      left: {
        value: "D",
        left: {
          value: "G",
          left: null,
          right: null
        },
        right: null
      },
      right: {
        value: "E",
        left: null,
        right: {
          value: "H",
          left: {
            value: "K",
            left: null,
            right: null
          }
        }
      }
    },
    right: {
      value: "C",
      left: {
        value: "F",
        left: {
          value: "I",
          left: null,
          right: null
        },
        right: {
          value: "J",
          left: null,
          right: null
        }
      },
      right: null
    }
  };

  render(tree, answer);

  it('breadthFirstTraverse', () => {
    expect(breadthFirstTraverse([tree], [])).toEqual(answer);
    expect(breadthFirstTraverse2([tree], [])).toEqual(answer);
  });
});

标签： javascriptjasmine