Use Boolean trick for Markdown AST as well

Author: tmcw

lib/output/markdown_ast.js

@@ -3,10 +3,6 @@ var mdast = require('mdast'),
   formatType = require('../markdown_format_type'),
   formatInlineTags = require('../format_inline_tags');
 
-function identity(x) {
-  return x;
-}
-
 /**
  * Given a hierarchy-nested set of comments, generate an mdast-compatible
  * Abstract Syntax Usable for generating Markdown output
@@ -43,7 +39,7 @@ function commentsToAST(comments, opts, callback) {
               u('text', ')')
             ]),
             param.properties && paramList(param.properties)
-          ].filter(identity))
+          ].filter(Boolean))
         ]);
       }));
     }
@@ -68,7 +64,7 @@ function commentsToAST(comments, opts, callback) {
                 u('text', ' '),
                 mdast.parse(formatInlineTags(property.description))
               ])
-            ].filter(identity))
+            ].filter(Boolean))
           }))
       ]);
     }
@@ -104,7 +100,7 @@ function commentsToAST(comments, opts, callback) {
         u('root', comment.members.instance.map(generate.bind(null, depth + 1))),
       !!comment.members.static.length &&
         u('root', comment.members.static.map(generate.bind(null, depth + 1)))
-    ].filter(identity));
+    ].filter(Boolean));
   }
 
   return callback(null, u('root', comments.map(function (comment) {