Merge pull request #1753 from loganfsmyth/optimize-call

Optimize NodePath#call a bit

src/babel/traversal/path/context.js

@@ -9,10 +9,9 @@ export function call(key) {
   if (!node) return;
 
   var opts = this.opts;
-  if (!opts[key] && !opts[node.type]) return;
 
-  var fns = [].concat(opts[key]);
+  for (var fns of [opts[key], opts[node.type] && opts[node.type][key]]){
-  if (opts[node.type]) fns = fns.concat(opts[node.type][key]);
+    if (!fns) continue;
 
     for (var fn of (fns: Array)) {
       if (!fn) continue;
@@ -37,6 +36,7 @@ export function call(key) {
       }
     }
   }
+}
 
 /**
  * Description

src/babel/traversal/visitors.js

@@ -21,6 +21,8 @@ export function explode(visitor) {
   // ensure visitors are objects
   ensureEntranceObjects(visitor);
 
+  ensureCallbackArrays(visitor);
+
   // add type wrappers
   for (let nodeType in visitor) {
     if (shouldIgnoreKey(nodeType)) continue;
@@ -73,6 +75,12 @@ export function explode(visitor) {
     }
   }
 
+  for (let nodeType in visitor) {
+    if (shouldIgnoreKey(nodeType)) continue;
+
+    ensureCallbackArrays(visitor[nodeType]);
+  }
+
   return visitor;
 }
 
@@ -126,6 +134,11 @@ function ensureEntranceObjects(obj) {
   }
 }
 
+function ensureCallbackArrays(obj){
+  if (obj.enter && !Array.isArray(obj.enter)) obj.enter = [obj.enter];
+  if (obj.exit && !Array.isArray(obj.exit)) obj.exit = [obj.exit];
+}
+
 function addQueries(visitor) {
   for (var selector in visitor.queries) {
     var fns = visitor.queries[selector];