FormContainer.jsx

/* FormContainer.jsx */

handleInput(e) {
     let value = e.target.value;
     let name = e.target.name;
     this.setState( prevState => {
        return { 
           newUser : {
                    ...prevState.newUser, [name]: value
                   }
        }
     }, () => console.log(this.state.newUser)
     )
 }