Function replayBeginWork

packages/react-reconciler/src/ReactFiberWorkLoop.js:3053–3137

(unitOfWork: Fiber)

}

function replayBeginWork(unitOfWork: Fiber): null | Fiber {
  // This is a fork of beginWork specifcally for replaying a fiber that
  // just suspended.

  const current = unitOfWork.alternate;

  let next;
  const isProfilingMode =
    enableProfilerTimer && (unitOfWork.mode & ProfileMode) !== NoMode;
  if (isProfilingMode) {
    startProfilerTimer(unitOfWork);
  }
  switch (unitOfWork.tag) {
    case SimpleMemoComponent:
    case FunctionComponent: {
      // Resolve `defaultProps`. This logic is copied from `beginWork`.
      // TODO: Consider moving this switch statement into that module. Also,
      // could maybe use this as an opportunity to say `use` doesn't work with
      // `defaultProps` :)
      const Component = unitOfWork.type;
      let context: any;
      if (!disableLegacyContext) {
        const unmaskedContext = getUnmaskedContext(unitOfWork, Component, true);
        context = getMaskedContext(unitOfWork, unmaskedContext);
      }
      next = replayFunctionComponent(
        current,
        unitOfWork,
        unitOfWork.pendingProps,
        Component,
        context,
        workInProgressRootRenderLanes,
      );
      break;
    }
    case ForwardRef: {
      // Resolve `defaultProps`. This logic is copied from `beginWork`.
      // TODO: Consider moving this switch statement into that module. Also,
      // could maybe use this as an opportunity to say `use` doesn't work with
      // `defaultProps` :)
      const Component = unitOfWork.type.render;
      next = replayFunctionComponent(
        current,
        unitOfWork,
        unitOfWork.pendingProps,
        Component,
        unitOfWork.ref,
        workInProgressRootRenderLanes,
      );
      break;
    }
    case HostComponent: {
      // Some host components are stateful (that's how we implement form
      // actions) but we don't bother to reuse the memoized state because it's
      // not worth the extra code. The main reason to reuse the previous hooks
      // is to reuse uncached promises, but we happen to know that the only
      // promises that a host component might suspend on are definitely cached
      // because they are controlled by us. So don't bother.