Fix SQLite query compatibility inside WITH clause

SQLite3::SQLException: circular reference

app/models/unit.rb

@@ -77,15 +77,13 @@ class Unit < ApplicationRecord
       .from(units).group(:base_id, :symbol)
   }
   scope :ordered, ->{
-    left_outer_joins(:base).order(ordering)
-  }
-
-  def self.ordering
-    [arel_table.coalesce(Arel::Table.new(:bases_units)[:symbol], arel_table[:symbol]),
+    left_outer_joins(:base).order([
+      arel_table.coalesce(Arel::Table.new(:bases_units)[:symbol], arel_table[:symbol]),
       arel_table[:base_id].not_eq(nil),
-     :multiplier,
-     :symbol]
-  end
+      arel_table[:multiplier],
+      arel_table[:symbol]
+    ])
+  }
 
   before_destroy do
     # TODO: disallow destruction if any object depends on this unit
@@ -114,11 +112,11 @@ class Unit < ApplicationRecord
 
   def successive
     units = Unit.arel_table
-    lead = Arel::Nodes::NamedFunction.new('LAG', [units[:id]])
-    window = Arel::Nodes::Window.new.order(*Unit.ordering)
-    lag_id = lead.over(window).as('lag_id')
-    Unit.with(
-      units: user.units.left_outer_joins(:base).select(units[Arel.star], lag_id)
-    ).where(units[:lag_id].eq(id)).first
+    Unit.with(units_with_lag: user.units.left_outer_joins(:base).select(
+      units[Arel.star],
+      Arel::Nodes::NamedFunction.new('LAG', [units[:id]])
+        .over(Arel::Nodes::Window.new.order(Unit.ordered.order_values)).as('lag_id')
+    )).from(Arel::Table.new(:units_with_lag).as(:units))
+      .where(units[:lag_id].eq(id)).take
   end
 end

test/system/units_test.rb

@@ -74,6 +74,30 @@ class UnitsTest < ApplicationSystemTestCase
     assert_equal values, Unit.last.attributes.slice(*values.keys)
   end
 
+  test "create updates view in order" do
+    # Destroy and re-create unit to verify its index position is unchanged.
+    sign_in(user: users.select { |u| u.confirmed? && u.units.many? }.sample)
+
+    link = all(:link_or_button, exact_text: t('units.unit.destroy')).sample
+    symbol = link.ancestor('tr').first(:link).text
+    index = link.ancestor('tbody').all('tr').index { |e| e.first(:link).text == symbol }
+    unit = @user.units.find_by(symbol: symbol)
+
+    link.click
+    if unit.base_id?
+      find_link(unit.base.symbol).ancestor('tr').click_on(t('units.unit.new_subunit'))
+      fill_in 'unit[multiplier]', with: unit.multiplier
+    else
+      click_on t('units.index.new_unit')
+    end
+    fill_in 'unit[symbol]', with: unit.symbol
+    click_on t('helpers.submit.create')
+
+    within "tbody > tr:nth-child(#{index+1})" do
+      assert_selector :link, exact_text: symbol
+    end
+  end
+
   test "new and edit on validation error" do
     # It's not possible to cause validation error on :edit with single unit
     LINK_LABELS.delete(:edit) unless @user.units.count > 1

test/test_helper.rb

@@ -35,6 +35,67 @@ class ActiveSupport::TestCase
     result
   end
 
+  # Range based string generation. Not finished, but saved as a potential
+  # reference for future work. To work properly it needs to sort in collation
+  # order of database.
+  #def random_between(from, to, maxlength)
+  #  # TODO: sort UNICODE_CHARS
+  #  byebug
+  #  result = ''
+  #  maxlength.times do |i|
+  #    case
+  #    when from[i] == to[i]
+  #      result += from[i]
+  #    else
+  #      from_index = UNICODE_CHARS.bsearch_index(from[i] || UNICODE_CHARS[0])
+  #      to_index = UNICODE_CHARS.bsearch_index(to[i])
+  #      index = rand(from_index..to_index)
+  #      case
+  #      when index == from_index
+  #        result += UNICODE_CHARS[index]
+  #        from[i+1..].each_char do |c|
+  #          from_index = UNICODE_CHARS.bsearch_index(from[i])
+  #          index = rand(from_index..UNICODE_CHARS.length-1)
+  #          result += UNICODE_CHARS[index]
+  #          break if index != from_index
+  #        end
+  #        if result == from
+  #          if result.length < maxlength
+  #            result += UNICODE_CHARS.sample
+  #          else
+  #            # TODO: succ result[i..]
+  #            # raise if result == to
+  #          end
+  #        end
+  #        break
+  #      when index == to_index
+  #        result += UNICODE_CHARS[index]
+  #        to[i+1..].each_char do |c|
+  #          to_index = UNICODE_CHARS.bsearch_index(to[i])
+  #          index = rand(-1..to_index)
+  #          break if index == -1
+  #          result += UNICODE_CHARS[index]
+  #          break if index != to_index
+  #        end
+  #        if result == to
+  #          if result.length > i+1
+  #            result = result[..-2]
+  #          else
+  #            # TODO: prev result[i..]
+  #            # raise if result == from
+  #          end
+  #        end
+  #        break
+  #      else
+  #        result += UNICODE_CHARS[index]
+  #        break
+  #      end
+  #    end
+  #  end
+  #  return result += UNICODE_CHARS.sample(rand(0..maxlength-i-1)).join
+  #  # if result == from/to ...
+  #end
+
   def deep_rand(*args)
     case args
     when Array