Function reconcileSingleElement

lib/assets/react-source/development/react.js:17858–17934

(returnFiber, currentFirstChild, element, expirationTime)

	  }

	  function reconcileSingleElement(returnFiber, currentFirstChild, element, expirationTime) {
	    var key = element.key;
	    var child = currentFirstChild;

	    while (child !== null) {
	      // TODO: If key === null and child.key === null, then this only applies to
	      // the first item in the list.
	      if (child.key === key) {
	        switch (child.tag) {
	          case Fragment:
	            {
	              if (element.type === REACT_FRAGMENT_TYPE) {
	                deleteRemainingChildren(returnFiber, child.sibling);
	                var existing = useFiber(child, element.props.children);
	                existing.return = returnFiber;

	                {
	                  existing._debugSource = element._source;
	                  existing._debugOwner = element._owner;
	                }

	                return existing;
	              }

	              break;
	            }

	          case Block:

	          // We intentionally fallthrough here if enableBlocksAPI is not on.
	          // eslint-disable-next-lined no-fallthrough

	          default:
	            {
	              if (child.elementType === element.type || ( // Keep this check inline so it only runs on the false path:
	               isCompatibleFamilyForHotReloading(child, element) )) {
	                deleteRemainingChildren(returnFiber, child.sibling);

	                var _existing3 = useFiber(child, element.props);

	                _existing3.ref = coerceRef(returnFiber, child, element);
	                _existing3.return = returnFiber;

	                {
	                  _existing3._debugSource = element._source;
	                  _existing3._debugOwner = element._owner;
	                }

	                return _existing3;
	              }

	              break;
	            }
	        } // Didn't match.


	        deleteRemainingChildren(returnFiber, child);
	        break;