Documentation issue, mount -> update

[anton-johansson]

Hi! I'm just getting started with Enzyme, and I think it looks great so far.

I think I've come across a documentation issue. I work with TypeScript, and when I look at the method update() of the return value of mount(...), like this:

const document = mount(<div>test</div>);
document.update();

The documentation in my IDE says the following:

    /**
     * Forces a re-render. Useful to run before checking the render output if something external may be updating
     * the state of the component somewhere.
     * Returns itself.
     *
     * NOTE: can only be called on a wrapper instance that is also the root instance.
     */

However, if I look at this page, it says:

Syncs the enzyme component tree snapshot with the react component tree.

If the latter is correct, this is definitely the function I'm looking for. I do have something external that is updating the state, so synchronizing the trees makes sense. If the former is correct, it's absolutely not something I want to do, because I feel like forcing a re-render breaks the integrity of the test. It should re-render on its own if everything is in order.

I hope you understand what I'm saying here, and I'd appreciate any answer that could indicate which of the documentation is correct (or if I'm looking at two different documentations completely!).

[mrdulin]

The document of .update() method needs more clearly.

something external may be updating the state of the component somewhere

What does "something external" means?

[ljharb]

JavaScript outside of your test.

[mrdulin]

@ljharb Sorry, still don't understand. There is an example in the doc .update() => Self.

The example uses a class component with the property count. How is this "something external"? I spent 2 minutes reading the source code of the .update method, the intent is not easy to understand.

Is there any other scenario considered as "something external"?