callbackawait.jsx

handleClick1 = async () => {
  await this._commonStateUpdate({foo: {$set: 1}});
  // This function requires the new value of foo in the state
  this.doSomethingElse();
}

handleClick2 = async () => {
  await this._commonStateUpdate({foo: {$set: 2}});
  // This function requires the new value of foo in the state
  this.doSomethingElse();
}
 
// Called by a lot of other functions
// May have some default state information
_commonStateUpdate = (updateTarget) => {
  // ... Do things that are common across calling functions
  const updateTargetDefault = {foo: 0, saving: false, loading: false};
  if(updateTarget){
    updateTarget = update(updateTargetDefault, updateTarget}
  }
  
  // IS THIS OK?
  const completeCallback = async () => {};
  this.setState(updateTarget, completeCallback);
  // Return a promise to listen for
  return completeCallback;
}