remove IIFE on class declarations #288

lib/6to5/templates/class.js

@@ -1,7 +0,0 @@
-(function () {
-  var CLASS_NAME = function () {
-
-  };
-
-  return CLASS_NAME;
-})()

lib/6to5/transformation/transformers/es6-classes.js

@@ -4,24 +4,11 @@ var t        = require("../../types");
 var _        = require("lodash");
 
 exports.ClassDeclaration = function (node, parent, file, scope) {
-  var built = new Class(node, file, scope).run();
-
-  var declar = t.variableDeclaration("let", [
-    t.variableDeclarator(node.id, built)
-  ]);
-  t.inheritsComments(declar, node);
-  return declar;
+  return new Class(node, file, scope, true).run();
 };
 
 exports.ClassExpression = function (node, parent, file, scope) {
-  return new Class(node, file, scope).run();
-};
-
-var getMemberExpressionObject = function (node) {
-  while (t.isMemberExpression(node)) {
-    node = node.object;
-  }
-  return node;
+  return new Class(node, file, scope, false).run();
 };
 
 /**
@@ -30,12 +17,14 @@ var getMemberExpressionObject = function (node) {
  * @param {Node} node
  * @param {File} file
  * @param {Scope} scope
+ * @param {Boolean} isStatement
  */
 
-function Class(node, file, scope) {
-  this.scope = scope;
-  this.node  = node;
-  this.file  = file;
+function Class(node, file, scope, isStatement) {
+  this.isStatement = isStatement;
+  this.scope       = scope;
+  this.node        = node;
+  this.file        = file;
 
   this.instanceMutatorMap = {};
   this.staticMutatorMap   = {};
@@ -51,50 +40,59 @@ function Class(node, file, scope) {
  */
 
 Class.prototype.run = function () {
-  var superClassArgument = this.superName;
-  var superClassCallee   = this.superName;
-  var superName          = this.superName;
-  var className          = this.className;
-  var file               = this.file;
+  var superName = this.superName;
+  var className = this.className;
+  var file      = this.file;
 
-  if (superName) {
-    if (t.isMemberExpression(superName)) {
-      superClassArgument = superClassCallee = getMemberExpressionObject(superName);
-    } else if (!t.isIdentifier(superName)) {
-      superClassArgument = superName;
-      superClassCallee   = superName = file.generateUidIdentifier("ref", this.scope);
-    }
+  //
+
+  var body = this.body = [];
+
+  var constructor = t.functionExpression(null, [], t.blockStatement([]));
+  if (this.node.id) constructor.id = className;
+  this.constructor = constructor;
+
+  body.push(t.variableDeclaration("let", [
+    t.variableDeclarator(className, constructor)
+  ]));
+
+  //
+
+  if (superName && t.isDynamic(superName)) {
+    // so we're only evaluating it once
+    var superRefName = "super";
+    if (className) superRefName = className.name + "Super";
+
+    var superRef = file.generateUidIdentifier(superRefName, this.scope);
+    body.unshift(t.variableDeclaration("var", [
+      t.variableDeclarator(superRef, superName)
+    ]));
+    superName = superRef;
   }
 
   this.superName = superName;
 
-  var container = util.template("class", {
-    CLASS_NAME: className
-  });
-
-  var block       = container.callee.expression.body;
-  var body        = this.body = block.body;
-  var constructor = this.constructor = body[0].declarations[0].init;
-
-  if (this.node.id) constructor.id = className;
-
-  var returnStatement = body.pop();
+  //
 
   if (superName) {
     body.push(t.expressionStatement(t.callExpression(file.addDeclaration("extends"), [className, superName])));
-
-    container.arguments.push(superClassArgument);
-    container.callee.expression.params.push(superClassCallee);
   }
 
   this.buildBody();
 
-  if (body.length === 1) {
-    // only a constructor so no need for a closure container
-    return constructor;
+  if (this.isStatement) {
+    return body;
   } else {
-    body.push(returnStatement);
-    return container;
+    if (body.length === 1) {
+      // only a constructor so no need for a closure container
+      return constructor;
+    } else {
+      body.push(t.returnStatement(className));
+      return t.callExpression(
+        t.functionExpression(null, [], t.blockStatement(body)),
+        []
+      );
+    }
   }
 };