no issues for milestone warning

src/milestones.coffee

@@ -4,11 +4,15 @@ req = require './request'
 module.exports =
     'get_current': (user, repo, cb) ->
         req.milestones user, repo, (err, data) ->
+            # Request errors.
             return cb err if err
+            # GitHub errors.
             return cb data.message if data.message
-            return cb 'No open milestones for a repo' unless data.length
-            # Go through the milestones looking for one that ends/ended soonest.
-            max = [ null, 'A' ]
-            for i, { due_on } of data when due_on < max[1]
-                max = [ parseInt(i), due_on ]
-            cb null, data[max[0]]
+            # Empty warning.
+            return cb null, 'No open milestones for repo' unless data.length
+            # Find the one due on soonest (string comparison).
+            max = { 'due_on': 'A' }
+            ( max = ms for ms in data when ms.due_on < max.due_on )
+            # Empty milestone?
+            return cb null, 'No issues for milestone' if max.open_issues + max.closed_issues is 0
+            cb null, null, max

test/milestones.coffee

@@ -20,7 +20,7 @@ module.exports =
                 }
             ]
 
-        milestones.get_current null, null, (err, milestone) ->
+        milestones.get_current null, null, (err, warn, milestone) ->
             assert.ifError err
             assert.equal milestone.number, 1
             done.call null
@@ -45,7 +45,7 @@ module.exports =
                 }
             ]
 
-        milestones.get_current null, null, (err, milestone) ->
+        milestones.get_current null, null, (err, warn, milestone) ->
             assert.ifError err
             assert.equal milestone.number, 2
             done.call null
@@ -54,14 +54,32 @@ module.exports =
         req.milestones = (user, repo, cb) ->
             cb null, []
 
-        milestones.get_current null, null, (err, milestone) ->
-            assert.equal err, 'No open milestones for a repo'
+        milestones.get_current null, null, (err, warn, milestone) ->
+            assert.ifError err
+            assert.equal warn, 'No open milestones for repo'
             done.call null
 
     'get current when not found': (done) ->
         req.milestones = (user, repo, cb) ->
             cb null, { 'message': 'Not Found' }
 
-        milestones.get_current null, null, (err, milestone) ->
+        milestones.get_current null, null, (err, warn, milestone) ->
             assert.equal err, 'Not Found'
+            done.call null
+
+    'get current when no issues': (done) ->
+        req.milestones = (user, repo, cb) ->
+            cb null, [
+                {
+                    'number': 1
+                    'created_at': '2013-01-01T00:00:00Z'
+                    'due_on': '2013-02-01T00:00:00Z',
+                    'open_issues': 0,
+                    'closed_issues': 0
+                }
+            ]
+
+        milestones.get_current null, null, (err, warn, milestone) ->
+            assert.ifError err
+            assert.equal warn, 'No issues for milestone'
             done.call null