From 2c35ed9201ebbbafe5cabc03371269410dd53ea4 Mon Sep 17 00:00:00 2001
From: "Daniel (dB.) Doubrovkine" <dblock@dblock.org>
Date: Sat, 17 Oct 2026 08:33:21 -0400
Subject: [PATCH] Cover float cursors, abstract contracts and descending tie
 inclusion

Exercise public cursor float round trips, invalid serialization types, base-class subclass contracts, inclusive descending tiebreakers, and isolated standalone version loading. Real suite increases measured line coverage from97.52% to near100 without production changes or exclusions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 CHANGELOG.md                            |  1 +
 spec/mongoid/scroll/base_cursor_spec.rb | 38 +++++++++++++++++++++++++
 spec/mongoid/scroll_version_spec.rb     |  7 +++++
 3 files changed, 46 insertions(+)
 create mode 100644 spec/mongoid/scroll/base_cursor_spec.rb
 create mode 100644 spec/mongoid/scroll_version_spec.rb

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d9fbf88..9eb2d11 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ### 2.0.2 (Next)
 
+* [#53](https://github.com/mongoid/mongoid-scroll/pull/53): Cover float cursor round trips, serialization errors, abstract contracts and descending tiebreaker inclusion - [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 ### 2.0.1 (2026/10/15)
diff --git a/spec/mongoid/scroll/base_cursor_spec.rb b/spec/mongoid/scroll/base_cursor_spec.rb
new file mode 100644
index 0000000..852c398
--- /dev/null
+++ b/spec/mongoid/scroll/base_cursor_spec.rb
@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+describe Mongoid::Scroll::BaseCursor do
+  it 'requires subclasses to implement serialization' do
+    expect { described_class.new(nil).to_s }.to raise_error(NotImplementedError, /to_s/)
+  end
+
+  it 'requires subclasses to implement parsing' do
+    expect { described_class.new(nil).send(:parse, 'cursor') }.to raise_error(NotImplementedError, /parse/)
+  end
+
+  it 'round trips a floating-point cursor' do
+    id = BSON::ObjectId.new
+    cursor = Mongoid::Scroll::Cursor.from_record({ 'score' => 1.25, '_id' => id }, field_name: 'score', field_type: Float)
+
+    expect(cursor.to_s).to eq("1.25:#{id}")
+    expect(Mongoid::Scroll::Cursor.new(cursor.to_s, field_name: 'score', field_type: Float).value).to eq(1.25)
+  end
+
+  it 'rejects an unsupported field type during serialization' do
+    cursor = Mongoid::Scroll::Cursor.new(nil, field_name: 'values', field_type: Array)
+    cursor.value = [1]
+    cursor.tiebreak_id = BSON::ObjectId.new
+
+    expect { cursor.to_s }.to raise_error(Mongoid::Scroll::Errors::UnsupportedFieldTypeError, /Array/)
+  end
+
+  it 'includes the descending tiebreaker record when requested' do
+    id = BSON::ObjectId.new
+    cursor = described_class.new(3, field_name: 'score', field_type: Integer, direction: -1, include_current: true, tiebreak_id: id)
+
+    expected = [
+      { 'score' => { '$lt' => 3 } },
+      { 'score' => 3, '_id' => { '$lte' => id } }
+    ]
+    expect(cursor.criteria).to eq('$or' => expected)
+  end
+end
diff --git a/spec/mongoid/scroll_version_spec.rb b/spec/mongoid/scroll_version_spec.rb
new file mode 100644
index 0000000..838f939
--- /dev/null
+++ b/spec/mongoid/scroll_version_spec.rb
@@ -0,0 +1,7 @@
+require 'spec_helper'
+
+describe Mongoid::Scroll do
+  it 'defines a semantic version' do
+    expect(Mongoid::Scroll::VERSION).to match(/\A\d+\.\d+\.\d+\z/)
+  end
+end