ignore queries performed in the cache

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master
 
+- add ability to ignore queries cached by the ORM with the new option `ignore_cached_queries` ([@gagalago][])
+
 ## 0.7.1 (2023-02-17)
 
 - Recognize private `#populate` and `#warmup` methods in Minitest classes. ([@palkan][])

README.md

@@ -331,6 +331,10 @@ self.show_table_stats = true
 # Ignore matching queries
 NPlusOneControl.ignore = /^(BEGIN|COMMIT|SAVEPOINT|RELEASE)/
 
+# Ignore queries in cache 
+# https://guides.rubyonrails.org/configuring.html#configuring-query-cache
+NPlusOneControl.ignore_cached_queries = false
+
 # ActiveSupport notifications event to track queries.
 # We track ActiveRecord event by default,
 # but can also track rom-rb events ('sql.rom') as well.

lib/n_plus_one_control.rb

@@ -19,7 +19,7 @@ module NPlusOneControl
 
   class << self
     attr_accessor :default_scale_factors, :verbose, :show_table_stats, :ignore, :event,
-      :backtrace_cleaner, :backtrace_length, :truncate_query_size
+      :backtrace_cleaner, :backtrace_length, :truncate_query_size, :ignore_cached_queries
 
     attr_reader :default_matching
 
@@ -115,6 +115,9 @@ def truncate_query(sql)
   # Ignore matching queries
   self.ignore = /^(BEGIN|COMMIT|SAVEPOINT|RELEASE)/
 
+  # Ignore queries cached
+  self.ignore_cached_queries = false
+
   # ActiveSupport notifications event to track queries.
   # We track ActiveRecord event by default,
   # but can also track rom-rb events ('sql.rom') as well.

lib/n_plus_one_control/executor.rb

@@ -22,6 +22,7 @@ def call
       def callback(_name, _start, _finish, _message_id, values) # rubocop:disable Metrics/CyclomaticComplexity,Metrics/LineLength
         return if %w[CACHE SCHEMA].include? values[:name]
         return if values[:sql].match?(NPlusOneControl.ignore)
+        return if values[:cached] && NPlusOneControl.ignore_cached_queries
 
         return unless @pattern.nil? || (values[:sql] =~ @pattern)
 

spec/n_plus_one_control/executor_spec.rb

@@ -71,4 +71,32 @@
       expect(result.last[1].size).to eq 3
     end
   end
+
+  context "with .ignore_cached_queries" do
+    let(:user) { create(:user) }
+    let(:populate) do
+      ->(n) { create_list(:post, n, user: user) }
+    end
+
+    let(:observable) do
+      -> { User.cache { Post.find_each(&:user) } }
+    end
+
+    around do |example|
+      old_ignore = NPlusOneControl.ignore_cached_queries
+      NPlusOneControl.ignore_cached_queries = true
+      example.call
+      NPlusOneControl.ignore_cached_queries = old_ignore
+    end
+
+    it "ignore queries already executed that are now in cache" do
+      result = described_class.new(population: populate).call(&observable)
+
+      expect(result.size).to eq 2
+      expect(result.first[0]).to eq 2
+      expect(result.first[1].size).to eq 2
+      expect(result.last[0]).to eq 3
+      expect(result.last[1].size).to eq 2
+    end
+  end
 end