Insert existing doc into a new group

lib/lexorank/rankable.rb

@@ -60,9 +60,11 @@ def move_to(position)
         if position == 0
           [nil, collection.first]
         else
+          current_position = collection.map(&:id).index(self.id)
+          not_in_collection = current_position.nil?
           # if item is currently in front of the index we just use position otherwise position - 1
           # if the item has no rank we use position - 1
-          position -= 1 if !self.send(self.class.ranking_column) || collection.map(&:id).index(self.id) > position
+          position -= 1 if no_rank? || not_in_collection || current_position > position
           collection.offset(position).limit(2)
         end
 
@@ -85,6 +87,9 @@ def move_to_top!
       move_to!(0)
     end
 
+    def no_rank?
+      !self.send(self.class.ranking_column)
+    end
   end
 
 end

test/group_by_test.rb

@@ -1,7 +1,6 @@
 require 'test_helper'
 
 class GroupByTest < ActiveSupport::TestCase
-
   should 'group paragraphs by page id and update accordingly' do
     page_1 = Page.create
     paragraphs_1 = create_sample_paragraphs(page_1)
@@ -20,11 +19,7 @@ class GroupByTest < ActiveSupport::TestCase
   end
 
   should 'resolve attribute names' do
-    class Paragraph1 < ActiveRecord::Base
-      self.table_name = "paragraphs"
-      rank!(group_by: :page_id)
-    end
-    assert_equal :page_id, Paragraph1.ranking_group_by
+    assert_equal :page_id, GroupedParagraph.ranking_group_by
 
     class Paragraph2 < ActiveRecord::Base
       self.table_name = "paragraphs"
@@ -45,17 +40,47 @@ class Paragraph3 < ActiveRecord::Base
     assert_nil Paragraph3.ranking_group_by
   end
 
-  def create_sample_paragraphs(page, count: 3)
-    paragraphs = []
-    count.times do
-      paragraphs << Paragraph.create(page: page)
+  describe 'moving to a different group' do
+    should 'insert into middle' do
+      page1, page2 = create_sample_pages(count: 2)
+      paragraph1, paragraph2, paragraph3 = create_sample_paragraphs(page1, clazz: GroupedParagraph)
+
+      new_paragraph = create_sample_paragraphs(page2, count: 1, clazz: GroupedParagraph).first
+
+      new_paragraph.page = page1
+      new_paragraph.move_to(2)
+      new_paragraph.save!
+
+      expected = [paragraph1, paragraph2, new_paragraph,  paragraph3]
+      assert_equal expected, GroupedParagraph.where(page_id: page1.id).ranked
     end
 
-    paragraphs.each_with_index do |paragraph, index|
-      paragraph.move_to!(index)
+    should 'insert at top' do
+      page1, page2 = create_sample_pages(count: 2)
+      paragraph1, paragraph2, paragraph3 = create_sample_paragraphs(page1, clazz: GroupedParagraph)
+
+      new_paragraph = create_sample_paragraphs(page2, count: 1, clazz: GroupedParagraph).first
+
+      new_paragraph.page = page1
+      new_paragraph.move_to(0)
+      new_paragraph.save!
+
+      expected = [new_paragraph, paragraph1, paragraph2,  paragraph3]
+      assert_equal expected, GroupedParagraph.where(page_id: page1.id).ranked
     end
 
-    paragraphs
-  end
+    should 'insert at the end' do
+      page1, page2 = create_sample_pages(count: 2)
+      paragraph1, paragraph2, paragraph3 = create_sample_paragraphs(page1, clazz: GroupedParagraph)
+
+      new_paragraph = create_sample_paragraphs(page2, count: 1, clazz: GroupedParagraph).first
 
+      new_paragraph.page = page1
+      new_paragraph.move_to(3)
+      new_paragraph.save!
+
+      expected = [paragraph1, paragraph2,  paragraph3, new_paragraph]
+      assert_equal expected, GroupedParagraph.where(page_id: page1.id).ranked
+    end
+  end
 end

test/models/grouped_paragraph.rb

@@ -0,0 +1,5 @@
+class GroupedParagraph < Paragraph
+  rank!(group_by: :page_id)
+end
+
+

test/ranking_test.rb

@@ -71,5 +71,4 @@ class Page2 < ActiveRecord::Base
     assert_equal('This rank should not be achievable using the Lexorank::Rankable module! ' +
       'Please report to https://github.com/richardboehme/lexorank/issues! The supplied ranks were nil and "0". Please include those in the issue description.', error.message)
   end
-
 end

test/test_helper.rb

@@ -16,6 +16,7 @@
 
 require 'models/page'
 require 'models/paragraph'
+require 'models/grouped_paragraph'
 
 class Minitest::Test
   include Shoulda::Context::DSL
@@ -51,16 +52,28 @@ def assert_not(condition)
     assert !condition
   end
 
-  def create_sample_pages(count: 3, clazz: Page)
-    pages = []
+  def create_sample_docs(count:, clazz:, create_with: {})
+    docs = []
     count.times do
-      pages << clazz.create
+      docs << clazz.create(create_with)
     end
 
-    pages.each_with_index do |page, index|
-      page.move_to!(index)
+    docs.each_with_index do |doc, index|
+      doc.move_to!(index)
     end
 
-    pages
+    docs
+  end
+
+  def create_sample_pages(count: 3, clazz: Page)
+    create_sample_docs(count: count, clazz: clazz)
+  end
+
+  def create_sample_paragraphs(page, count: 3, clazz: Paragraph)
+    create_sample_docs(
+      count: count,
+      clazz: clazz,
+      create_with: { page: page },
+    )
   end
 end