Function deleteChild

code/new-context-api/public/app.js:8274–8293

(returnFiber, childToDelete)

// live outside of this function.
function ChildReconciler(shouldTrackSideEffects) {
  function deleteChild(returnFiber, childToDelete) {
    if (!shouldTrackSideEffects) {
      // Noop.
      return;
    }
    // Deletions are added in reversed order so we add it to the front.
    // At this point, the return fiber's effect list is empty except for
    // deletions, so we can just append the deletion to the list. The remaining
    // effects aren't added until the complete phase. Once we implement
    // resuming, this may not be true.
    var last = returnFiber.lastEffect;
    if (last !== null) {
      last.nextEffect = childToDelete;
      returnFiber.lastEffect = childToDelete;
    } else {
      returnFiber.firstEffect = returnFiber.lastEffect = childToDelete;
    }
    childToDelete.nextEffect = null;
    childToDelete.effectTag = Deletion;
  }

  function deleteRemainingChildren(returnFiber, currentFirstChild) {
    if (!shouldTrackSideEffects) {