From 2c4ec96acaaf820e2c662495da6c04a2a89737bc Mon Sep 17 00:00:00 2001
From: Konstantin Rudy <konstantin.rudy@gmail.com>
Date: Thu, 29 Oct 2020 18:09:19 +0300
Subject: [PATCH 1/2] Added optional: true to read_marks [Fixes #120]

---
 lib/unread/read_mark.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/unread/read_mark.rb b/lib/unread/read_mark.rb
index da3fbfe..9e17214 100644
--- a/lib/unread/read_mark.rb
+++ b/lib/unread/read_mark.rb
@@ -1,5 +1,5 @@
 class ReadMark < ActiveRecord::Base
-  belongs_to :readable, polymorphic: true, inverse_of: :read_marks
+  belongs_to :readable, polymorphic: true, inverse_of: :read_marks, optional: true
 
   validates_presence_of :reader_id, :reader_type, :readable_type
 

From da170631006f47404025c00313764ec3285ac3e3 Mon Sep 17 00:00:00 2001
From: Konstantin Rudy <konstantin.rudy@gmail.com>
Date: Fri, 30 Oct 2020 20:01:52 +0300
Subject: [PATCH 2/2] Added specs for the optional reader case [Fixes #120]

---
 lib/unread/base.rb           |  6 +++++-
 lib/unread/read_mark.rb      |  2 +-
 spec/unread/readable_spec.rb | 28 ++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lib/unread/base.rb b/lib/unread/base.rb
index 3cfa080..a1289c6 100644
--- a/lib/unread/base.rb
+++ b/lib/unread/base.rb
@@ -8,7 +8,11 @@ def acts_as_reader
       ReadMark.reader_classes ||= []
 
       unless ReadMark.reader_classes.include?(self)
-        ReadMark.belongs_to :reader, polymorphic: true, inverse_of: :read_marks
+        if ActiveRecord::VERSION::MAJOR < 5
+          ReadMark.belongs_to :reader, polymorphic: true, inverse_of: :read_marks
+        else
+          ReadMark.belongs_to :reader, polymorphic: true, inverse_of: :read_marks, optional: true
+        end
 
         has_many :read_marks, dependent: :delete_all, as: :reader, inverse_of: :reader
 
diff --git a/lib/unread/read_mark.rb b/lib/unread/read_mark.rb
index 9e17214..da3fbfe 100644
--- a/lib/unread/read_mark.rb
+++ b/lib/unread/read_mark.rb
@@ -1,5 +1,5 @@
 class ReadMark < ActiveRecord::Base
-  belongs_to :readable, polymorphic: true, inverse_of: :read_marks, optional: true
+  belongs_to :readable, polymorphic: true, inverse_of: :read_marks
 
   validates_presence_of :reader_id, :reader_type, :readable_type
 
diff --git a/spec/unread/readable_spec.rb b/spec/unread/readable_spec.rb
index c8add8c..ef275fc 100644
--- a/spec/unread/readable_spec.rb
+++ b/spec/unread/readable_spec.rb
@@ -253,6 +253,34 @@
 
       expect(@reader.read_marks.single.count).to eq 1
     end
+
+    context 'when the reader class defines a default_scope that excludes tha reader instance' do
+      before { ReadMark.stub(belongs_to_required_by_default: true) }
+
+      let!(:reader_class) do
+        CustomReader = Class.new(ActiveRecord::Base) do
+          self.primary_key = 'number'
+          self.table_name = 'readers'
+
+          acts_as_reader
+
+          default_scope { where.not(name: 'foo') }
+        end
+      end
+      let!(:reader) { reader_class.create!(name: 'foo') }
+      let(:document) { Document.create! }
+
+      before do
+        wait
+        document
+      end
+
+      subject { document.mark_as_read!(for: reader) }
+
+      it 'does not raise_error' do
+        expect { subject }.not_to raise_error
+      end
+    end
   end
 
   describe '.mark_as_read!' do