From 89983cead94901e9fdfcde2446499aba2ed17a9e Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Sun, 2 Aug 2015 21:37:12 +0100
Subject: [PATCH] make comment retainment for multiple nodes more predictable -
 fixes #2146

---
 .../babel/src/traversal/path/replacement.js   |  3 ++-
 packages/babel/src/types/index.js             | 26 +++++++++++++++----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/packages/babel/src/traversal/path/replacement.js b/packages/babel/src/traversal/path/replacement.js
index 16bda31e7a..abaf3d5778 100644
--- a/packages/babel/src/traversal/path/replacement.js
+++ b/packages/babel/src/traversal/path/replacement.js
@@ -56,7 +56,8 @@ export function replaceWithMultiple(nodes: Array<Object>) {
   this.resync();
 
   nodes = this._verifyNodeList(nodes);
-  t.inheritsComments(nodes[0], this.node);
+  t.inheritLeadingComments(nodes[0], this.node);
+  t.inheritTrailingComments(nodes[nodes.length - 1], this.node);
   this.node = this.container[this.key] = null;
   this.insertAfter(nodes);
   if (!this.node) this.dangerouslyRemove();
diff --git a/packages/babel/src/types/index.js b/packages/babel/src/types/index.js
index 8975faea2f..2f9bd85aeb 100644
--- a/packages/babel/src/types/index.js
+++ b/packages/babel/src/types/index.js
@@ -318,14 +318,30 @@ export function removeComments(node: Object): Object {
  */
 
 export function inheritsComments(child: Object, parent: Object): Object {
-  if (child && parent) {
-    for (var key of (COMMENT_KEYS: Array)) {
-      child[key] = uniq(compact([].concat(child[key], parent[key])));
-    }
-  }
+  inheritTrailingComments(child, parent);
+  inheritLeadingComments(child, parent);
+  inheritInnerComments(child, parent);
   return child;
 }
 
+export function inheritTrailingComments(child, parent) {
+  _inheritComments("trailingComments", child, parent);
+}
+
+export function inheritLeadingComments(child, parent) {
+  _inheritComments("leadingComments", child, parent);
+}
+
+export function inheritInnerComments(child, parent) {
+  _inheritComments("innerComments", child, parent);
+}
+
+function _inheritComments(key, child, parent) {
+  if (child && parent) {
+    child[key] = uniq(compact([].concat(child[key], parent[key])));
+  }
+}
+
 /**
  * Inherit all contextual properties from `parent` node to `child` node.
  */