Use new methods in PaginatedTimeline

This calls the new methods on each entry, simplifying the code, and
allowing us to stub the response, rather than relying on the objects
set up in `seed_document_event_history`

app/models/document/paginated_timeline.rb

@@ -35,33 +35,15 @@ def query
   end
 
   def entries_on_newer_editions(edition)
-    @entries_on_newer_editions ||= entries.select do |entry|
-      if entry.is_a?(EditorialRemark)
-        entry.edition_id > edition.id
-      else
-        entry.item_id > edition.id
-      end
-    end
+    entries.select { |e| e.is_for_newer_edition?(edition) }
   end
 
   def entries_on_current_edition(edition)
-    @entries_on_current_edition ||= entries.select do |entry|
-      if entry.is_a?(EditorialRemark)
-        entry.edition_id == edition.id
-      else
-        entry.item_id == edition.id
-      end
-    end
+    entries.select { |e| e.is_for_current_edition?(edition) }
   end
 
   def entries_on_previous_editions(edition)
-    @entries_on_previous_editions ||= entries.select do |entry|
-      if entry.is_a?(EditorialRemark)
-        entry.edition_id < edition.id
-      else
-        entry.item_id < edition.id
-      end
-    end
+    entries.select { |e| e.is_for_older_edition?(edition) }
   end
 
   def total_count

test/unit/app/models/document/paginated_timeline_test.rb

@@ -263,30 +263,75 @@ class PaginatedTimelineTest < ActiveSupport::TestCase
     end
   end
 
-  describe "#entries_on_newer_editions" do
-    it "returns entries on newer editions than the one passed in" do
-      timeline = Document::PaginatedTimeline.new(document: @document, page: 1)
-      expected_entries = timeline.entries.slice(1, 2)
+  describe "filtering entries" do
+    let(:entries_for_newer_editions) do
+      2.times.map do
+        stub("entry", is_for_newer_edition?: true, is_for_current_edition?: false, is_for_older_edition?: false)
+      end
+    end
 
-      assert_equal expected_entries, timeline.entries_on_newer_editions(@first_edition)
+    let(:entries_for_current_edition) do
+      4.times.map do
+        stub("entry", is_for_newer_edition?: false, is_for_current_edition?: true, is_for_older_edition?: false)
+      end
     end
-  end
-
-  describe "#entries_on_current_edition" do
-    it "returns entries for the edition passed in" do
-      timeline = Document::PaginatedTimeline.new(document: @document, page: 1)
-      expected_entries = timeline.entries - timeline.entries.slice(1, 2)
 
-      assert_equal expected_entries, timeline.entries_on_current_edition(@first_edition)
+    let(:entries_for_older_editions) do
+      3.times.map do
+        stub("entry", is_for_newer_edition?: false, is_for_current_edition?: false, is_for_older_edition?: true)
+      end
     end
-  end
 
-  describe "#entries_on_previous_editions" do
-    it "returns entries on previous editions" do
-      timeline = Document::PaginatedTimeline.new(document: @document, page: 1)
-      expected_entries = timeline.entries - timeline.entries.slice(1, 2)
+    let(:all_entries) do
+      [*entries_for_newer_editions, *entries_for_current_edition, *entries_for_older_editions]
+    end
+
+    let(:timeline) { Document::PaginatedTimeline.new(document: @document, page: 1) }
+
+    before do
+      timeline.stubs(:entries).returns(all_entries)
+    end
+
+    describe "#entries_on_newer_editions" do
+      it "returns entries on newer editions than the one passed in" do
+        assert_equal entries_for_newer_editions, timeline.entries_on_newer_editions(@first_edition)
+      end
+
+      it "calls the entries with the expected edition" do
+        all_entries.each do |entry|
+          entry.expects(:is_for_newer_edition?).with(@first_edition)
+        end
+
+        timeline.entries_on_newer_editions(@first_edition)
+      end
+    end
+
+    describe "#entries_on_current_edition" do
+      it "returns entries for the edition passed in" do
+        assert_equal entries_for_current_edition, timeline.entries_on_current_edition(@first_edition)
+      end
+
+      it "calls the entries with the expected edition" do
+        all_entries.each do |entry|
+          entry.expects(:is_for_current_edition?).with(@first_edition)
+        end
 
-      assert_equal expected_entries, timeline.entries_on_previous_editions(@newest_edition)
+        timeline.entries_on_current_edition(@first_edition)
+      end
+    end
+
+    describe "#entries_on_previous_editions" do
+      it "returns entries on previous editions" do
+        assert_equal entries_for_older_editions, timeline.entries_on_previous_editions(@newest_edition)
+      end
+
+      it "calls the entries with the expected edition" do
+        all_entries.each do |entry|
+          entry.expects(:is_for_older_edition?).with(@first_edition)
+        end
+
+        timeline.entries_on_previous_editions(@first_edition)
+      end
     end
   end