Function resetWorkInProgress

docs/external/js/react-dom.development.js:23922–23980

(workInProgress, renderExpirationTime)

  } // Used to reuse a Fiber for a second pass.

  function resetWorkInProgress(workInProgress, renderExpirationTime) {
    // This resets the Fiber to what createFiber or createWorkInProgress would
    // have set the values to before during the first pass. Ideally this wouldn't
    // be necessary but unfortunately many code paths reads from the workInProgress
    // when they should be reading from current and writing to workInProgress.
    // We assume pendingProps, index, key, ref, return are still untouched to
    // avoid doing another reconciliation.
    // Reset the effect tag but keep any Placement tags, since that's something
    // that child fiber is setting, not the reconciliation.
    workInProgress.effectTag &= Placement; // The effect list is no longer valid.

    workInProgress.nextEffect = null;
    workInProgress.firstEffect = null;
    workInProgress.lastEffect = null;
    var current = workInProgress.alternate;

    if (current === null) {
      // Reset to createFiber's initial values.
      workInProgress.childExpirationTime = NoWork;
      workInProgress.expirationTime = renderExpirationTime;
      workInProgress.child = null;
      workInProgress.memoizedProps = null;
      workInProgress.memoizedState = null;
      workInProgress.updateQueue = null;
      workInProgress.dependencies = null;

      {
        // Note: We don't reset the actualTime counts. It's useful to accumulate
        // actual time across multiple render passes.
        workInProgress.selfBaseDuration = 0;
        workInProgress.treeBaseDuration = 0;
      }
    } else {
      // Reset to the cloned values that createWorkInProgress would've.
      workInProgress.childExpirationTime = current.childExpirationTime;
      workInProgress.expirationTime = current.expirationTime;
      workInProgress.child = current.child;
      workInProgress.memoizedProps = current.memoizedProps;
      workInProgress.memoizedState = current.memoizedState;
      workInProgress.updateQueue = current.updateQueue; // Clone the dependencies object. This is mutated during the render phase, so
      // it cannot be shared with the current fiber.

      var currentDependencies = current.dependencies;
      workInProgress.dependencies = currentDependencies === null ? null : {
        expirationTime: currentDependencies.expirationTime,
        firstContext: currentDependencies.firstContext,
        responders: currentDependencies.responders
      };

      {
        // Note: We don't reset the actualTime counts. It's useful to accumulate
        // actual time across multiple render passes.
        workInProgress.selfBaseDuration = current.selfBaseDuration;
        workInProgress.treeBaseDuration = current.treeBaseDuration;
      }
    }

    return workInProgress;