Function beginWork

docs/external/js/react-dom.development.js:18545–18846

(current, workInProgress, renderExpirationTime)

  }

  function beginWork(current, workInProgress, renderExpirationTime) {
    var updateExpirationTime = workInProgress.expirationTime;

    {
      if (workInProgress._debugNeedsRemount && current !== null) {
        // This will restart the begin phase with a new fiber.
        return remountFiber(current, workInProgress, createFiberFromTypeAndProps(workInProgress.type, workInProgress.key, workInProgress.pendingProps, workInProgress._debugOwner || null, workInProgress.mode, workInProgress.expirationTime));
      }
    }

    if (current !== null) {
      var oldProps = current.memoizedProps;
      var newProps = workInProgress.pendingProps;

      if (oldProps !== newProps || hasContextChanged() || ( // Force a re-render if the implementation changed due to hot reload:
       workInProgress.type !== current.type )) {
        // If props or context changed, mark the fiber as having performed work.
        // This may be unset if the props are determined to be equal later (memo).
        didReceiveUpdate = true;
      } else if (updateExpirationTime < renderExpirationTime) {
        didReceiveUpdate = false; // This fiber does not have any pending work. Bailout without entering
        // the begin phase. There's still some bookkeeping we that needs to be done
        // in this optimized path, mostly pushing stuff onto the stack.

        switch (workInProgress.tag) {
          case HostRoot:
            pushHostRootContext(workInProgress);
            resetHydrationState();
            break;

          case HostComponent:
            pushHostContext(workInProgress);

            if (workInProgress.mode & ConcurrentMode && renderExpirationTime !== Never && shouldDeprioritizeSubtree(workInProgress.type, newProps)) {
              {
                markSpawnedWork(Never);
              } // Schedule this fiber to re-render at offscreen priority. Then bailout.


              workInProgress.expirationTime = workInProgress.childExpirationTime = Never;
              return null;
            }

            break;

          case ClassComponent:
            {
              var Component = workInProgress.type;

              if (isContextProvider(Component)) {
                pushContextProvider(workInProgress);
              }

              break;
            }

          case HostPortal:
            pushHostContainer(workInProgress, workInProgress.stateNode.containerInfo);