This is a simple base component class for true server-side rendering
with emulation of server interaction.

It is intended for use with **class components** and **without** any
external state management libraries like Redux. Basically it's intended
for pure setState()-based code.

## Algorithm

- Write code in such a way that it still works if DOM is not available
- Make your components inherit from `SSRComponent`:
  - Use `doRender` instead of `render`
  - Use `init` instead of `constructor`
  - Everything else stays the same
  - You can additionally override `serializeState` and `unserializeState`
    if your state isn't directly JSON-serializable
- Implement SSR:
  - Declare `store = {}`
  - Render your component using `react-test-renderer` with `store={store}` in props
  - Make sure your code tracks all fetch() requests (server interactions) during render
  - And of course mock fetch() (or analogue) to use internal server-side calls
  - Wait until all fetch() requests complete
  - Re-render until the component stops issuing additional requests
  - Render HTML using `renderToHtml(testRenderer.toJSON())`
  - Serialize state using `JSON.stringify(SSRComponent.serializeStore(store))`
- Hydrate the rendered HTML in your frontend code:
  - Call `ReactDOM.hydrate()` instead of `ReactDOM.render()`
  - Pass serialized state from the last step of SSR to your top-level SSRComponent

## virtualRender.js

Simpler (but less compatible) alternative to `react-test-renderer`.

USAGE:

```jsx
import virtualRender from 'virtualRender.js';

const options = {};
let html = virtualRender(<Component {...props}>, options);
while (options.shouldUpdate)
{
    html = virtualRender(<Component {...props}>, options);
}
```

## Author and License

Author: Vitaliy Filippov, 2021+

License: Dual-license MPL 1.1+ or GNU LGPL 3.0+ (file-level copyleft)