fix root lftq increment on update when virtual root

lib/acts_as_nested_interval/instance_methods.rb

@@ -69,7 +69,7 @@ def set_nested_interval(lftp, lftq)
 
     def set_nested_interval_for_top
       if self.class.virtual_root
-        set_nested_interval *next_root_lft
+        set_nested_interval(*next_root_lft)
       else
         set_nested_interval 0, 1
       end
@@ -100,15 +100,18 @@ def nested_interval_scope
     # Updates record, updating descendants if parent association updated,
     # in which case caller should first acquire table lock.
     def update_nested_interval
-      if read_attribute(nested_interval_foreign_key).nil?
-        set_nested_interval_for_top
-      elsif !association(:parent).updated?
+      changed = send(:"#{nested_interval_foreign_key}_changed?")
+      if !changed
         db_self = self.class.find(id, :lock => true)
         write_attribute(nested_interval_foreign_key, db_self.read_attribute(nested_interval_foreign_key))
         set_nested_interval db_self.lftp, db_self.lftq
-      else # move
-        # No locking in this case -- caller should have acquired table lock.
-        update_nested_interval_move
+      else
+        if read_attribute(nested_interval_foreign_key).nil? # root move
+          set_nested_interval_for_top
+        else # child move
+          # No locking in this case -- caller should have acquired table lock.
+          update_nested_interval_move
+        end
       end
     end
 
@@ -217,4 +220,4 @@ def next_root_lft
     end
 
   end
-end
+end

test/acts_as_nested_interval_test.rb

@@ -178,8 +178,8 @@ def test_virtual_root_allocation
     r2 = Region.create name: "Romania", :parent => r1
     r3 = Region.create name: "Asia"
     r4 = Region.create name: "America"
-    assert_equal [["Europe", 0.5, 1.0], ["Romania", 0.6666666666666666, 1.0],
-      ["Asia", 0.3333333333333333, 0.5], ["America", 0.25, 0.3333333333333333]],
+    assert_equal [["Europe", 1.0/2, 1.0], ["Romania", 2.0/3, 1.0],
+      ["Asia", 1.0/3, 1.0/2], ["America", 1.0/4, 1.0/3]],
       Region.preorder.map { |r| [r.name, r.lft, r.rgt] }
   end
 
@@ -190,9 +190,33 @@ def test_rebuild_nested_interval_tree
     r3 = Region.create name: "Asia"
     r4 = Region.create name: "America"
     Region.rebuild_nested_interval_tree!
-    assert_equal [["Europe", 0.5, 1.0], ["Romania", 0.6666666666666666, 1.0],
-      ["Asia", 0.3333333333333333, 0.5], ["America", 0.25, 0.3333333333333333]],
+    assert_equal [["Europe", 0.5, 1.0], ["Romania", 2.0/3, 1.0],
+      ["Asia", 1.0/3, 1.0/2], ["America", 1.0/4, 1.0/3]],
       Region.preorder.map { |r| [r.name, r.lft, r.rgt] }
   end
 
+  def test_root_update_keeps_interval
+    Region.virtual_root = true
+    r1 = Region.create name: "Europe"
+    r2 = Region.create name: "Romania", parent: r1
+    r3 = Region.create name: "Asia"
+    r4 = Region.create name: "America"
+    lftq = r4.lftq
+    r4.name = 'USA'
+    r4.save
+    assert_equal lftq, r4.lftq
+  end
+
+  def test_move_to_root_recomputes_interval
+    Region.virtual_root = true
+    r1 = Region.create name: "Europe"
+    r2 = Region.create name: "Romania", parent: r1
+    r3 = Region.create name: "Asia"
+    r4 = Region.create name: "America"
+    lftq = r2.lftq
+    r2.parent = nil
+    r2.save
+    assert_not_equal lftq, r2.lftq
+  end
+
 end