Function processUpdateQueue

packages/react-server/src/ReactFizzClassComponent.js:586–623

(
  internalInstance: InternalInstance,
  inst: any,
  props: any,
  maskedLegacyContext: any,
)

}

function processUpdateQueue(
  internalInstance: InternalInstance,
  inst: any,
  props: any,
  maskedLegacyContext: any,
): void {
  if (internalInstance.queue !== null && internalInstance.queue.length > 0) {
    const oldQueue = internalInstance.queue;
    const oldReplace = internalInstance.replace;
    internalInstance.queue = null;
    internalInstance.replace = false;

    if (oldReplace && oldQueue.length === 1) {
      inst.state = oldQueue[0];
    } else {
      let nextState = oldReplace ? oldQueue[0] : inst.state;
      let dontMutate = true;
      for (let i = oldReplace ? 1 : 0; i < oldQueue.length; i++) {
        const partial = oldQueue[i];
        const partialState =
          typeof partial === 'function'
            ? partial.call(inst, nextState, props, maskedLegacyContext)
            : partial;
        if (partialState != null) {
          if (dontMutate) {
            dontMutate = false;
            nextState = assign({}, nextState, partialState);
          } else {
            assign(nextState, partialState);
          }
        }
      }
      inst.state = nextState;
    }
  } else {
    internalInstance.queue = null;
  }
}

// Invokes the mount life-cycles on a previously never rendered instance.
export function mountClassInstance(