Checks if a mirror is a typedef mirror first.

pkg/docgen/lib/docgen.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * **docgen** is a tool for creating machine readable representations of Dart
  * code metadata, including: classes, members, comments and annotations.
  *
  * docgen is run on a `.dart` file or a directory containing `.dart` files.
  *
@@ skipping 723 matching lines @@
  * A container to categorize classes into the following groups: abstract
  * classes, regular classes, typedefs, and errors.
  */
 class ClassGroup {
   Map<String, Class> classes = {};
   Map<String, Typedef> typedefs = {};
   Map<String, Class> errors = {};
 
   void addClass(ClassMirror mirror) {
     _currentClass = mirror;
-    var clazz = _class(mirror);
-
-    // Adding inherited parent variables and methods.
-    clazz.parent().forEach((parent) {
-      if (_isVisible(clazz)) {
-        parent.addSubclass(clazz);
-      }
-    });
-
-    clazz.ensureComments();
-
-    if (clazz.isError()) {
-      errors[mirror.simpleName] = clazz;
-    } else if (mirror.isTypedef) {
+    if (mirror.isTypedef) {
       if (_includePrivate || !mirror.isPrivate) {
         entityMap[mirror.qualifiedName] = new Typedef(mirror.simpleName,
             mirror.value.returnType.qualifiedName, _commentToHtml(mirror),
             _generics(mirror), _parameters(mirror.value.parameters),
             _annotations(mirror), mirror.qualifiedName,  _isHidden(mirror),
             mirror.owner.qualifiedName);
         typedefs[mirror.simpleName] = entityMap[mirror.qualifiedName];
       }
-    } else if (mirror.isClass) {
-      classes[mirror.simpleName] = clazz;
     } else {
-      throw new ArgumentError('${mirror.simpleName} - no class type match. ');
+      var clazz = _class(mirror);
+  
+      // Adding inherited parent variables and methods.
+      clazz.parent().forEach((parent) {
+        if (_isVisible(clazz)) {
+          parent.addSubclass(clazz);
+        }
+      });
+  
+      clazz.ensureComments();
+  
+      if (clazz.isError()) {
+        errors[mirror.simpleName] = clazz;
+      } else if (mirror.isClass) {
+        classes[mirror.simpleName] = clazz;
+      } else {
+        throw new ArgumentError('${mirror.simpleName} - no class type match. ');
+      }
     }
   }
 
   /**
    * Checks if the given name is a key for any of the Class Maps.
    */
   bool containsKey(String name) {
     return classes.containsKey(name) || errors.containsKey(name);
   }
   
@@ skipping 294 matching lines @@
   String qualifiedName;
   List<String> parameters;
 
   Annotation(this.qualifiedName, this.parameters);
 
   Map toMap() => {
     'name': qualifiedName,
     'parameters': parameters
   };
 }