2.1.2 [DOMLevel2Traversal:2000] Section 2.6, Deleting Content with a Range


The specification states:

 Note that if deletion of a Range leaves adjacent Text nodes, they are not 
 automatically merged, and empty Text nodes are not automatically removed. Two Text
  nodes should be joined only if each is the container of one of the boundary-points 
 of a Range whose contents are deleted. To merge adjacent Text nodes, or remove 
 empty text nodes, the normalize() method on the Node interface should be used.

IE9 Mode, IE10 Mode, IE11 Mode, and EdgeHTML Mode (All Versions)

If a Range corresponds to a complete text node and deleteContents() is called, the empty text node is removed from the tree.