# TIL about React, Enzyme and Babel on 19.04.2018

1. If you are doing SSR, don't forget to check if an image is loaded before mount. `img.onload` is not captured when the image is loaded before JavaScript is executed.
2. To tweak `ref` before `componentDidMount` is executed, extend the class and override the method to set the `ref`. It's much cleaner than stubbing the method.
3. To call its super method of a bound method with Babel, save the super method as another class property. Class properties are directly set on an instance instead of constructor's prototype.