Function updateFromMap

code/styling/public/app.js:9174–9214

(existingChildren, returnFiber, newIdx, newChild, expirationTime)

  }

  function updateFromMap(existingChildren, returnFiber, newIdx, newChild, expirationTime) {
    if (typeof newChild === 'string' || typeof newChild === 'number') {
      // Text nodes don't have keys, so we neither have to check the old nor
      // new node for the key. If both are text nodes, they match.
      var matchedFiber = existingChildren.get(newIdx) || null;
      return updateTextNode(returnFiber, matchedFiber, '' + newChild, expirationTime);
    }

    if (typeof newChild === 'object' && newChild !== null) {
      switch (newChild.$$typeof) {
        case REACT_ELEMENT_TYPE:
          {
            var _matchedFiber = existingChildren.get(newChild.key === null ? newIdx : newChild.key) || null;
            if (newChild.type === REACT_FRAGMENT_TYPE) {
              return updateFragment(returnFiber, _matchedFiber, newChild.props.children, expirationTime, newChild.key);
            }
            return updateElement(returnFiber, _matchedFiber, newChild, expirationTime);
          }
        case REACT_PORTAL_TYPE:
          {
            var _matchedFiber2 = existingChildren.get(newChild.key === null ? newIdx : newChild.key) || null;
            return updatePortal(returnFiber, _matchedFiber2, newChild, expirationTime);
          }
      }

      if (isArray$1(newChild) || getIteratorFn(newChild)) {
        var _matchedFiber3 = existingChildren.get(newIdx) || null;
        return updateFragment(returnFiber, _matchedFiber3, newChild, expirationTime, null);
      }

      throwOnInvalidObjectType(returnFiber, newChild);
    }

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

    return null;
  }

  /**
   * Warns if there is a duplicate or missing key