Function updateSlot

code/new-context-api/public/app.js:8477–8533

(returnFiber, oldFiber, newChild, expirationTime)

  }

  function updateSlot(returnFiber, oldFiber, newChild, expirationTime) {
    // Update the fiber if the keys match, otherwise return null.

    var key = oldFiber !== null ? oldFiber.key : null;

    if (typeof newChild === 'string' || typeof newChild === 'number') {
      // Text nodes don't have keys. If the previous node is implicitly keyed
      // we can continue to replace it without aborting even if it is not a text
      // node.
      if (key !== null) {
        return null;
      }
      return updateTextNode(returnFiber, oldFiber, '' + newChild, expirationTime);
    }

    if (typeof newChild === 'object' && newChild !== null) {
      switch (newChild.$$typeof) {
        case REACT_ELEMENT_TYPE:
          {
            if (newChild.key === key) {
              if (newChild.type === REACT_FRAGMENT_TYPE) {
                return updateFragment(returnFiber, oldFiber, newChild.props.children, expirationTime, key);
              }
              return updateElement(returnFiber, oldFiber, newChild, expirationTime);
            } else {
              return null;
            }
          }
        case REACT_PORTAL_TYPE:
          {
            if (newChild.key === key) {
              return updatePortal(returnFiber, oldFiber, newChild, expirationTime);
            } else {
              return null;
            }
          }
      }

      if (isArray$1(newChild) || getIteratorFn(newChild)) {
        if (key !== null) {
          return null;
        }

        return updateFragment(returnFiber, oldFiber, newChild, expirationTime, null);
      }

      throwOnInvalidObjectType(returnFiber, newChild);
    }

    {
      if (typeof newChild === 'function') {
        warnOnFunctionType();
      }
    }

    return null;
  }