add .alias() helper

Author: tj

lib/builder.js

@@ -449,21 +449,19 @@ Builder.prototype.buildAliases = function(fn){
               var name = builder.conf.name;
 
               var aliases = conf.scripts.map(function(script){
-                // TODO: remove special-casing root
                 var alias = self.root
                   ? self.conf.name + '/deps/' + name + '/' + script
                   : self.basename + '/deps/' + name + '/' + script;
 
-                var js = 'require.alias("' + builder.basename + '/' + script + '", "' + alias + '");\n';
-                return js;
+                return builder.alias(alias, script);
               });
 
               if (main) {
                 var alias = self.root
                   ? self.conf.name + '/deps/' + name + '/index.js'
                   : self.basename + '/deps/' + name + '/index.js';
 
-                aliases.push('require.alias("' + builder.basename + '/' + main + '", "' + alias + '");\n');
+                aliases.push(builder.alias(alias, main));
               }
 
               aliases = aliases.join('');
@@ -486,14 +484,31 @@ Builder.prototype.buildAliases = function(fn){
         : self.basename;
 
       if (conf.main) {
-        res.push('require.alias("' + name + '/' + conf.main + '", "' + name + '/index.js");\n');
+        res.push(self.alias(name + '/index.js', conf.main));
       }
 
       fn(null, res.join('\n'));
     });
   });
 };
 
+/**
+ * Return an alias from script `a` to `b`.
+ *
+ * @param {String} a
+ * @param {String} b
+ * @return {String}
+ * @api private
+ */
+
+Builder.prototype.alias = function(a, b){
+  var name = this.root
+    ? this.conf.name
+    : this.basename;
+
+  return 'require.alias("' + name + '/' + b + '", "' + a + '");\n';
+};
+
 /**
  * Build `type` and invoke `fn`.
  *