function unwindContexts(from: Fiber, to: Fiber) {
let node = from;
while (node !== null && node !== to && node.alternate !== to) {
switch (node.tag) {
case ClassComponent:
popContextProvider(node);
break;
case HostComponent:
popHostContext(node);
break;
case HostRoot:
popHostContainer(node);
break;
case HostPortal:
popHostContainer(node);
break;
}
if (__DEV__) {
stopWorkTimer(node);
}
node = node.return;
}
}
function completeUnitOfWork(workInProgress: Fiber): Fiber | null {
while (true) {
// The current, flushed, state of this fiber is the alternate.
// Ideally nothing should rely on this, but relying on it here
// means that we don't need an additional field on the work in
// progress.
const current = workInProgress.alternate;
const next = completeWork(current, workInProgress);
const returnFiber = workInProgress.return;
const siblingFiber = workInProgress.sibling;
resetWorkPriority(workInProgress);
if (next !== null) {
if (__DEV__) {
stopWorkTimer(workInProgress);
}
if (__DEV__ && ReactFiberInstrumentation.debugTool) {
ReactFiberInstrumentation.debugTool.onCompleteWork(workInProgress);
}
// If completing this work spawned new work, do that next. We'll come
// back here again.
return next;
}
if (returnFiber !== null) {
// Append all the effects of the subtree and this fiber onto the effect
// list of the parent. The completion order of the children affects the
// side-effect order.
if (returnFiber.firstEffect === null) {
returnFiber.firstEffect = workInProgress.firstEffect;
}
if (workInProgress.lastEffect !== null) {
if (returnFiber.lastEffect !== null) {
returnFiber.lastEffect.nextEffect = workInProgress.firstEffect;
}
returnFiber.lastEffect = workInProgress.lastEffect;
}
// If this fiber had side-effects, we append it AFTER the children's
// side-effects. We can perform certain side-effects earlier if
// needed, by doing multiple passes over the effect list. We don't want
// to schedule our own side-effect on our own list because if end up
// reusing children we'll schedule this effect onto itself since we're
// at the end.
const effectTag = workInProgress.effectTag;
// Skip both NoWork and PerformedWork tags when creating the effect list.
// PerformedWork effect is read by React DevTools but shouldn't be committed.
if (effectTag > PerformedWork) {
if (returnFiber.lastEffect !== null) {
returnFiber.lastEffect.nextEffect = workInProgress;
} else {
returnFiber.firstEffect = workInProgress;
}
returnFiber.lastEffect = workInProgress;
}
}
if (__DEV__) {
stopWorkTimer(workInProgress);
}
if (__DEV__ && ReactFiberInstrumentation.debugTool) {
ReactFiberInstrumentation.debugTool.onCompleteWork(workInProgress);
}
if (siblingFiber !== null) {
// If there is more work to do in this returnFiber, do that next.
return siblingFiber;
} else if (returnFiber !== null) {
// If there's no more work in this returnFiber. Complete the returnFiber.
workInProgress = returnFiber;
continue;
} else {
// We've reached the root. Unless we're current performing deferred
// work, we should commit the completed work immediately. If we are
// performing deferred work, returning null indicates to the caller
// that we just completed the root so they can handle that case correctly.
if (nextPriorityLevel < HighPriority) {
// Otherwise, we should commit immediately.
commitAllWork(workInProgress);
} else {
pendingCommit = workInProgress;
}
return null;
}
}
// Without this explicit null return Flow complains of invalid return type
// TODO Remove the above while(true) loop
// eslint-disable-next-line no-unreachable
return null;
}