Fix NoMethodError when trying to access the :previous revision on a m…

…odel that doesn't have previous revisions [Alex Soto]
collectiveidea · Apr 18, 2008 · c10ca9a · c10ca9a
1 parent 1c9cb5c
commit c10ca9a
Show file tree

Hide file tree

Showing 3 changed files with 13 additions and 2 deletions.
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,7 @@
  acts_as_audited ChangeLog
 -------------------------------------------------------------------------------
-
+* 2008-04-18 - Fix NoMethodError when trying to access the :previous revision
+               on a model that doesn't have previous revisions [Alex Soto]
 * 2008-03-21 - added #changed_attributes to get access to the changes before a
                save [Chris Parker]
 * 2007-12-16 - Added #revision_at for retrieving a revision from a specific

diff --git a/lib/acts_as_audited.rb b/lib/acts_as_audited.rb
@@ -142,7 +142,10 @@ def revision_at(date_or_time)
       private
 
         def changes(from_version = 1)
-          from_version = audits.find(:first).version if from_version == :previous
+          if from_version == :previous
+            last_audit = audits.find(:first)
+            from_version = last_audit ? last_audit.version : 1
+          end
           changes = {}
           result = audits.find(:all, :conditions => ['version >= ?', from_version]).collect do |audit|
             attributes = (audit.changes || {}).inject({}) do |attrs, (name, values)|

diff --git a/test/acts_as_audited_test.rb b/test/acts_as_audited_test.rb
@@ -154,6 +154,13 @@ def test_save_revision_records_audit
     end
   end
 
+  def test_without_previous_audits
+    user = create_user
+    user.audits.destroy_all
+    assert_nothing_raised(NoMethodError) { user.revision(:previous) }
+  end
+
+
 private
 
   def create_user(attrs = {})