[#258,model][xs]: tiny bugfix for cases where fields in raw state contain a non-string - fixes #258.

src/model.js

@@ -105,11 +105,12 @@ my.Dataset = Backbone.Model.extend({
     } 
 
     // fields is an array of strings (i.e. list of field headings/ids)
-    if (fields && fields.length > 0 && typeof fields[0] === 'string') {
+    if (fields && fields.length > 0 && typeof(fields[0]) != 'object') {
       // Rename duplicate fieldIds as each field name needs to be
       // unique.
       var seen = {};
       fields = _.map(fields, function(field, index) {
+        field = field.toString();
         // cannot use trim as not supported by IE7
         var fieldId = field.replace(/^\s+|\s+$/g, '');
         if (fieldId === '') {

test/model.test.js

@@ -180,6 +180,21 @@ test('_normalizeRecordsAndFields', function () {
         records: null
       },
     },
+    {
+      in_: {
+        fields: [ 1, 1, 3 ],
+        records: null
+      },
+      exp: {
+        fields: [
+          {id: '1'},
+          {id: '11'},
+          {id: '3'}
+        ],
+        records: null
+      },
+    },
+    // field is *not* a string
     // records array but no fields
     {
       in_: {
@@ -267,6 +282,7 @@ test('_normalizeRecordsAndFields', function () {
     out = dataset._normalizeRecordsAndFields(item.in_.records, item.in_.fields);
     deepEqual(out, item.exp);
   });
+
 });