Method constructor

packages/mobx-react/__tests__/observer.test.tsx:1134–1144

(props)

            }

            constructor(props) {
                super(props)
                // Synchronize our observableProp with the actual prop on the first render.
                this.observableProp = this.props.prop
                makeObservable(this, {
                    observableProp: observable,
                    computed: computed,
                    // Mutates observable therefore must be action
                    componentDidUpdate: action
                })
            }

            componentDidMount(): void {
                // Reactions/autoruns must be created in componenDidMount (not in constructor).