Merge pull request #64 from clio/refactor_version_compatibility_with_ci

Refactor gem to be compatible with multiple ActiveRecord versions; Adding ci github action

Author: wendy-clio

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: CI
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        gemfile:
+          - Gemfile
+          - Gemfile.5.2
+          - Gemfile.6.0
+          - Gemfile.6.1
+    env:
+      BUNDLE_GEMFILE: ${{ matrix.gemfile }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.7
+      - name: Install dependencies
+        run: bundle install
+      - name: Run tests
+        run:
+          bundle exec rspec

.gitignore

@@ -10,6 +10,7 @@
 /test/tmp/
 /test/version_tmp/
 /tmp/
+.idea/*
 
 # Used by dotenv library to load environment variables.
 # .env

Gemfile

@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
 
+gem "activerecord", ">=7"
 # Specify your gem's dependencies in jit_preloader.gemspec
 gemspec

README.md

@@ -173,6 +173,20 @@ end
 
 ```
 
+Furthermore, there is an argument `max_ids_per_query` setting max ids per query. This helps prevent running a single query with too large list of ids which may be less efficient than splitting into multiple queries.
+```ruby
+class Contact < ActiveRecord::Base
+  has_many :addresses
+  has_many_aggregate :addresses, :count_all, :count, "*", max_ids_per_query: 10
+end
+
+Contact.jit_preload.each do |contact|
+  contact.addresses_count_all
+end
+# SELECT contact_id, COUNT(*) FROM addresses WHERE contact_id IN (1, 2, 3, ... ,10) GROUP BY contact_id
+# SELECT contact_id, COUNT(*) FROM addresses WHERE contact_id IN (11, 12, 13) GROUP BY contact_id
+```
+
 ### Preloading a subset of an association
 
 There are often times when you want to preload a subset of an association, or change how the SQL statement is generated. For example, if a `Contact` model has
@@ -213,6 +227,7 @@ end
 ### Jit preloading globally across your application
 
 The JitPreloader can be globally enabled, in which case most N+1 queries in your app should just disappear. It is off by default.
+The `max_ids_per_query` argument on loading aggregate methods can also apply on a global level.
 
 ```ruby
 # Can be true or false
@@ -223,12 +238,24 @@ JitPreloader.globally_enabled = true
 # so that you can turn it on or off dynamically.
 JitPreloader.globally_enabled = ->{ $redis.get('always_jit_preload') == 'on' }
 
+# Setting global max ids constraint on all aggregation methods.
+JitPreloader.max_ids_per_query = 10
+
+class Contact < ActiveRecord::Base
+  has_many :emails
+  has_many_aggregate :emails, :count_all, :count, "*"
+end
+
 # When enabled globally, this would not generate an N+1 query.
 Contact.all.each do |contact|
   contact.emails.each do |email|
     # do something
   end
+  # When max_ides_per_query is set globally, the aggregate method will split query base on the limit.
+  contact.emails_count_all
 end
+
+
 ```
 
 ## What it doesn't solve

jit_preloader.gemspec

@@ -18,7 +18,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "activerecord", ">= 7", "< 8"
+  spec.add_dependency "activerecord", "< 8"
   spec.add_dependency "activesupport"
 
   spec.add_development_dependency "bundler"

lib/jit_preloader/active_record/base.rb

@@ -18,7 +18,7 @@ def clear_jit_preloader!
     end
   end
 
-  if Gem::Version.new(ActiveRecord::VERSION::STRING) >= Gem::Version.new("6.0.0")
+  if Gem::Version.new(ActiveRecord::VERSION::STRING) >= Gem::Version.new("7.0.0")
     def preload_scoped_relation(name:, base_association:, preload_scope: nil)
       return jit_preload_scoped_relations[name] if jit_preload_scoped_relations&.key?(name)
 

lib/jit_preloader/preloader.rb

@@ -3,25 +3,47 @@ class Preloader < ActiveRecord::Associations::Preloader
 
     attr_accessor :records
 
-    def self.attach(records)
-      new(records: records.dup, associations: nil).tap do |loader|
-        records.each do |record|
-          record.jit_preloader = loader
+    if Gem::Version.new(ActiveRecord::VERSION::STRING) >= Gem::Version.new("7.0.0")
+      def self.attach(records)
+        new(records: records.dup, associations: nil).tap do |loader|
+          records.each do |record|
+            record.jit_preloader = loader
+          end
         end
       end
-    end
 
-    def jit_preload(associations)
-      # It is possible that the records array has multiple different classes (think single table inheritance).
-      # Thus, it is possible that some of the records don't have an association.
-      records_with_association = records.reject{|r| r.class.reflect_on_association(associations).nil? }
+      def jit_preload(associations)
+        # It is possible that the records array has multiple different classes (think single table inheritance).
+        # Thus, it is possible that some of the records don't have an association.
+        records_with_association = records.reject{|r| r.class.reflect_on_association(associations).nil? }
+
+        # Some of the records may already have the association loaded and we should not load them again
+        records_requiring_loading = records_with_association.select{|r| !r.association(associations).loaded? }
+
+        self.class.new(records: records_requiring_loading, associations: associations).call
+      end
+    else
+      def self.attach(records)
+        new.tap do |loader|
+          loader.records = records.dup
+          records.each do |record|
+            record.jit_preloader = loader
+          end
+        end
+      end
 
-      # Some of the records may already have the association loaded and we should not load them again
-      records_requiring_loading = records_with_association.select{|r| !r.association(associations).loaded? }
+      def jit_preload(associations)
+        # It is possible that the records array has multiple different classes (think single table inheritance).
+        # Thus, it is possible that some of the records don't have an association.
+        records_with_association = records.reject{ |record| record.class.reflect_on_association(associations).nil? }
 
-      self.class.new(records: records_requiring_loading, associations: associations).call
+        # Some of the records may already have the association loaded and we should not load them again
+        records_requiring_loading = records_with_association.select{ |record| !record.association(associations).loaded? }
+        preload records_with_association, associations
+      end
     end
 
+
     # We do not want the jit_preloader to be dumpable
     # If you dump a ActiveRecord::Base object that has a jit_preloader instance variable
     # you will also end up dumping all of the records the preloader has reference to.

lib/jit_preloader/version.rb

@@ -1,3 +1,3 @@
 module JitPreloader
-  VERSION = "2.0.2"
+  VERSION = "2.1.0"
 end