allow NodePaths to be returned in node removal/replacement methods and coerce them to nodes

src/babel/traversal/path/modification.js

@@ -140,6 +140,8 @@ export function _verifyNodeList(nodes) {
       throw new Error(`Node list contains a non-object node with the index of ${i}`);
     } else if (!node.type) {
       throw new Error(`Node list contains a node without a type with the index of ${i}`);
+    } else if (node instanceof NodePath) {
+      nodes[i] = node.node;
     }
   }
 

src/babel/traversal/path/replacement.js

@@ -1,4 +1,5 @@
 import codeFrame from "../../helpers/code-frame";
+import NodePath from "./index";
 import traverse from "../index";
 import * as t from "../../types";
 import parse from "../../helpers/parse";
@@ -79,6 +80,10 @@ export function replaceWith(replacement, whateverAllowed) {
     throw new Error("You can't replace this node, we've already removed it");
   }
 
+  if (replacement instanceof NodePath) {
+    replacement = replacement.node;
+  }
+
   if (!replacement) {
     throw new Error("You passed `path.replaceWith()` a falsy node, use `path.dangerouslyRemove()` instead");
   }