From 4d263ea3cdbbfee8e770d47b670bedff513618d9 Mon Sep 17 00:00:00 2001
From: Sascha Karnatz <sascha@blish.cloud>
Date: Fri, 29 Nov 2024 17:15:48 +0100
Subject: [PATCH] Use an inner select for CanCanCan abilities

The previous solution only worked if the pg_search_document had a page_id. If another search document without a page relation was added and an ability was present, the document couldn't be found, because the generate SQL had an inner join that was using the page_id. The new solution is using a sub select and only filters pg_search_documents if the page_id is present on that document entries.
---
 lib/alchemy-pg_search.rb           |  9 ++-------
 spec/lib/alchemy-pg_search_spec.rb | 10 ++++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/lib/alchemy-pg_search.rb b/lib/alchemy-pg_search.rb
index 61fbc5d..4b7f7e1 100644
--- a/lib/alchemy-pg_search.rb
+++ b/lib/alchemy-pg_search.rb
@@ -60,13 +60,8 @@ def self.search(query, ability: nil)
       query = ::PgSearch.multisearch(query).includes(:searchable)
 
       if ability
-        # left_joins method is not usable here, because the order of the joins are incorrect
-        # and would result in a SQL error. We can receive the correct query order with these
-        # odd left join string
-        # Ref: https://guides.rubyonrails.org/active_record_querying.html#using-a-string-sql-fragment
-        query = query
-                  .joins("LEFT JOIN alchemy_pages ON alchemy_pages.id = pg_search_documents.page_id")
-                  .merge(Alchemy::Page.accessible_by(ability, :read))
+        inner_ability_select = Alchemy::Page.select(:id).merge(Alchemy::Page.accessible_by(ability, :read))
+        query = query.where("page_id IS NULL OR page_id IN (#{inner_ability_select.to_sql})")
       end
 
       query
diff --git a/spec/lib/alchemy-pg_search_spec.rb b/spec/lib/alchemy-pg_search_spec.rb
index a8339ad..de0ae4b 100644
--- a/spec/lib/alchemy-pg_search_spec.rb
+++ b/spec/lib/alchemy-pg_search_spec.rb
@@ -101,6 +101,16 @@
         it 'should find two pages' do
           expect(result.length).to eq(2)
         end
+
+        context "with other search documents" do
+          let!(:other_search_document) do
+            PgSearch::Document.new(content: "Page").save(validate: false)
+          end
+
+          it 'should find three pages' do
+            expect(result.length).to eq(3)
+          end
+        end
       end
     end
   end