Function updateContextConsumer

code/new-context-api/public/app.js:9740–9782

(current, workInProgress, renderExpirationTime)

  }

  function updateContextConsumer(current, workInProgress, renderExpirationTime) {
    var context = workInProgress.type;
    var newProps = workInProgress.pendingProps;
    var oldProps = workInProgress.memoizedProps;

    var newValue = context._currentValue;
    var changedBits = context._changedBits;

    if (hasLegacyContextChanged()) {
      // Normally we can bail out on props equality but if context has changed
      // we don't do the bailout and we have to reuse existing props instead.
    } else if (changedBits === 0 && oldProps === newProps) {
      return bailoutOnAlreadyFinishedWork(current, workInProgress);
    }
    workInProgress.memoizedProps = newProps;

    var observedBits = newProps.unstable_observedBits;
    if (observedBits === undefined || observedBits === null) {
      // Subscribe to all changes by default
      observedBits = MAX_SIGNED_31_BIT_INT;
    }
    // Store the observedBits on the fiber's stateNode for quick access.
    workInProgress.stateNode = observedBits;

    if ((changedBits & observedBits) !== 0) {
      // Context change propagation stops at matching consumers, for time-
      // slicing. Continue the propagation here.
      propagateContextChange(workInProgress, context, changedBits, renderExpirationTime);
    } else if (oldProps !== null && oldProps.children === newProps.children) {
      // No change. Bailout early if children are the same.
      return bailoutOnAlreadyFinishedWork(current, workInProgress);
    }

    var render = newProps.children;

    {
      warning(typeof render === 'function', 'A context consumer was rendered with multiple children, or a child ' + "that isn't a function. A context consumer expects a single child " + 'that is a function. If you did pass a function, make sure there ' + 'is no trailing or leading whitespace around it.');
    }

    var newChildren = render(newValue);
    reconcileChildren(current, workInProgress, newChildren);
    return workInProgress.child;
  }

  /*
  function reuseChildrenEffects(returnFiber : Fiber, firstChild : Fiber) {