From 8d81373ef8e85ef4cf1387ecb6c44890afad1185 Mon Sep 17 00:00:00 2001
From: Mike Gerwitz <mikegerwitz@gnu.org>
Date: Thu, 13 Feb 2014 05:21:26 -0500
Subject: [PATCH] Began named trait implementation

Does not yet support staging object like classes
---
 lib/Trait.js            | 52 ++++++++++++++++++++++--
 test/Trait/NamedTest.js | 87 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+), 3 deletions(-)
 create mode 100644 test/Trait/NamedTest.js

diff --git a/lib/Trait.js b/lib/Trait.js
index 1179079..0e5074b 100644
--- a/lib/Trait.js
+++ b/lib/Trait.js
@@ -30,12 +30,54 @@ function Trait()
         case 1:
             return Trait.extend.apply( this, arguments );
             break;
+
+        case 2:
+            return createNamedTrait.apply( this, arguments );
+            break;
+
+        default:
+            throw Error( "Missing trait name or definition" );
     }
 };
 
 
+/**
+ * Create a named trait
+ *
+ * @param  {string}  name  trait name
+ * @param  {Object}  def   trait definition
+ *
+ * @return  {Function}  named trait
+ */
+function createNamedTrait( name, dfn )
+{
+    if ( arguments.length > 2 )
+    {
+        throw Error(
+            "Expecting at most two arguments for definition of named " +
+                "Trait " + name + "'; " + arguments.length + " given"
+        );
+    }
+
+    if ( typeof name !== 'string' )
+    {
+        throw Error(
+            "First argument of named class definition must be a string"
+        );
+    }
+
+    dfn.__name = name;
+
+    return Trait.extend( dfn );
+}
+
+
 Trait.extend = function( dfn )
 {
+    // store any provided name, since we'll be clobbering it (the definition
+    // object will be used to define the hidden abstract class)
+    var name = dfn.__name || '(Trait)';
+
     // we need at least one abstract member in order to declare a class as
     // abstract (in this case, our trait class), so let's create a dummy one
     // just in case DFN does not contain any abstract members itself
@@ -52,9 +94,13 @@ Trait.extend = function( dfn )
     // and here we can see that traits are quite literally abstract classes
     var tclass = AbstractClass( dfn );
 
-    TraitType.__trait = true;
-    TraitType.__acls  = tclass;
-    TraitType.__ccls  = null;
+    TraitType.__trait  = true;
+    TraitType.__acls   = tclass;
+    TraitType.__ccls   = null;
+    TraitType.toString = function()
+    {
+        return ''+name;
+    };
 
     // traits are not permitted to define constructors
     if ( tclass.___$$methods$$['public'].__construct !== undefined )
diff --git a/test/Trait/NamedTest.js b/test/Trait/NamedTest.js
new file mode 100644
index 0000000..d4a5a48
--- /dev/null
+++ b/test/Trait/NamedTest.js
@@ -0,0 +1,87 @@
+/**
+ * Tests named trait definitions
+ *
+ *  Copyright (C) 2014 Mike Gerwitz
+ *
+ *  This file is part of GNU ease.js.
+ *
+ *  ease.js is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+require( 'common' ).testCase(
+{
+    caseSetUp: function()
+    {
+        this.Sut   = this.require( 'Trait' );
+        this.Class = this.require( 'class' );
+    },
+
+
+    /**
+     * If a trait is not given a name, then converting it to a string should
+     * indicate that it is anonymous. Further, to disambiguate from
+     * anonymous classes, we should further indicate that it is a trait.
+     *
+     * This test is fragile in the sense that it tests for an explicit
+     * string: this is intended, since some developers may rely on this
+     * string (even though they really should use Trait.isTrait), and so it
+     * should be explicitly documented.
+     */
+    'Anonymous trait is properly indicated when converted to string':
+    function()
+    {
+        var given = this.Sut( {} ).toString();
+        this.assertEqual( given, '(Trait)' );
+    },
+
+
+    /**
+     * Analagous to named classes: we should provide the name when
+     * converting to a string to aid in debugging.
+     */
+    'Named trait contains name when converted to string': function()
+    {
+        var name = 'FooTrait',
+            T    = this.Sut( name, {} );
+
+        this.assertOk( T.toString().match( name ) );
+    },
+
+
+    /**
+     * We assume that, if two or more arguments are provided, that the
+     * definition is named.
+     */
+    'Named trait definition cannot contain zero or more than two arguments':
+    function()
+    {
+        var Sut = this.Sut;
+        this.assertThrows( function() { Sut(); } );
+        this.assertThrows( function() { Sut( 1, 2, 3 ); } );
+    },
+
+
+    /**
+     * Operating on the same assumption as the above test.
+     */
+    'First argument in named trait definition must be a string':
+    function()
+    {
+        var Sut = this.Sut;
+        this.assertThrows( function()
+        {
+            Sut( {}, {} );
+        } );
+    },
+} );