Enhance QueryRecorder to support finding queries by source + memoizing of read only attributes

lib/quality/test_level.rb

@@ -33,6 +33,7 @@ module Quality
         serializers
         services
         sidekiq
+        support_specs
         tasks
         uploaders
         validators

spec/lib/quality/test_level_spec.rb

@@ -21,7 +21,7 @@ RSpec.describe Quality::TestLevel do
     context 'when level is unit' do
       it 'returns a pattern' do
         expect(subject.pattern(:unit))
-          .to eq("spec/{bin,config,db,dependencies,factories,finders,frontend,graphql,haml_lint,helpers,initializers,javascripts,lib,models,policies,presenters,rack_servers,replicators,routing,rubocop,serializers,services,sidekiq,tasks,uploaders,validators,views,workers,elastic_integration}{,/**/}*_spec.rb")
+          .to eq("spec/{bin,config,db,dependencies,factories,finders,frontend,graphql,haml_lint,helpers,initializers,javascripts,lib,models,policies,presenters,rack_servers,replicators,routing,rubocop,serializers,services,sidekiq,support_specs,tasks,uploaders,validators,views,workers,elastic_integration}{,/**/}*_spec.rb")
       end
     end
 
@@ -82,7 +82,7 @@ RSpec.describe Quality::TestLevel do
     context 'when level is unit' do
       it 'returns a regexp' do
         expect(subject.regexp(:unit))
-          .to eq(%r{spec/(bin|config|db|dependencies|factories|finders|frontend|graphql|haml_lint|helpers|initializers|javascripts|lib|models|policies|presenters|rack_servers|replicators|routing|rubocop|serializers|services|sidekiq|tasks|uploaders|validators|views|workers|elastic_integration)})
+          .to eq(%r{spec/(bin|config|db|dependencies|factories|finders|frontend|graphql|haml_lint|helpers|initializers|javascripts|lib|models|policies|presenters|rack_servers|replicators|routing|rubocop|serializers|services|sidekiq|support_specs|tasks|uploaders|validators|views|workers|elastic_integration)})
       end
     end
 

spec/support/helpers/query_recorder.rb

@@ -2,12 +2,15 @@
 
 module ActiveRecord
   class QueryRecorder
-    attr_reader :log, :skip_cached, :cached
+    attr_reader :log, :skip_cached, :cached, :data
+    UNKNOWN = %w(unknown unknown).freeze
 
-    def initialize(skip_cached: true, &block)
+    def initialize(skip_cached: true, query_recorder_debug: false, &block)
+      @data = Hash.new { |h, k| h[k] = { count: 0, occurrences: [], backtrace: [] } }
       @log = []
       @cached = []
       @skip_cached = skip_cached
+      @query_recorder_debug = query_recorder_debug
       # force replacement of bind parameters to give tests the ability to check for ids
       ActiveRecord::Base.connection.unprepared_statement do
         ActiveSupport::Notifications.subscribed(method(:callback), 'sql.active_record', &block)
@@ -19,30 +22,62 @@ module ActiveRecord
       Gitlab::BacktraceCleaner.clean_backtrace(caller).each { |line| Rails.logger.debug("   --> #{line}") }
     end
 
+    def get_sql_source(sql)
+      matches = sql.match(/,line:(?<line>.*):in\s+`(?<method>.*)'\*\//)
+      matches ? [matches[:line], matches[:method]] : UNKNOWN
+    end
+
+    def store_sql_by_source(values: {}, backtrace: nil)
+      full_name = get_sql_source(values[:sql]).join(':')
+      @data[full_name][:count] += 1
+      @data[full_name][:occurrences] << values[:sql]
+      @data[full_name][:backtrace] << backtrace
+    end
+
+    def find_query(query_regexp, limit, first_only: false)
+      out = []
+
+      @data.each_pair do |k, v|
+        if v[:count] > limit && k.match(query_regexp)
+          out << [k, v[:count]]
+          break if first_only
+        end
+      end
+
+      out.flatten! if first_only
+      out
+    end
+
+    def occurrences_by_line_method
+      @occurrences_by_line_method ||= @data.sort_by { |_, v| v[:count] }
+    end
+
     def callback(name, start, finish, message_id, values)
-      show_backtrace(values) if ENV['QUERY_RECORDER_DEBUG']
+      store_backtrace = ENV['QUERY_RECORDER_DEBUG'] || @query_recorder_debug
+      backtrace = store_backtrace ? show_backtrace(values) : nil
 
       if values[:cached] && skip_cached
         @cached << values[:sql]
       elsif !values[:name]&.include?("SCHEMA")
         @log << values[:sql]
+        store_sql_by_source(values: values, backtrace: backtrace)
       end
     end
 
     def count
-      @log.count
+      @count ||= @log.count
     end
 
     def cached_count
-      @cached.count
+      @cached_count ||= @cached.count
     end
 
     def log_message
-      @log.join("\n\n")
+      @log_message ||= @log.join("\n\n")
     end
 
     def occurrences
-      @log.group_by(&:to_s).transform_values(&:count)
+      @occurrences ||= @log.group_by(&:to_s).transform_values(&:count)
     end
   end
 end

spec/support_specs/helpers/active_record/query_recorder_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe ActiveRecord::QueryRecorder do
+  class TestQueries < ActiveRecord::Base
+    self.table_name = 'schema_migrations'
+  end
+
+  describe 'detecting the right number of calls and their origin' do
+    it 'detects two separate queries' do
+      control = ActiveRecord::QueryRecorder.new query_recorder_debug: true do
+        2.times { TestQueries.count }
+        TestQueries.first
+      end
+
+      # Test first_only flag works as expected
+      expect(control.find_query(/.*query_recorder_spec.rb.*/, 0, first_only: true))
+        .to eq(control.find_query(/.*query_recorder_spec.rb.*/, 0).first)
+      # Check #find_query
+      expect(control.find_query(/.*/, 0).size)
+        .to eq(control.data.keys.size)
+      # Ensure exactly 2 COUNT queries were detected
+      expect(control.occurrences_by_line_method.last[1][:occurrences]
+               .find_all {|i| i.match(/SELECT COUNT/) }.count).to eq(2)
+      # Ensure exactly 1 LIMIT 1 (#first)
+      expect(control.occurrences_by_line_method.first[1][:occurrences]
+               .find_all { |i| i.match(/ORDER BY.*#{TestQueries.table_name}.*LIMIT 1/) }.count).to eq(1)
+
+      # Ensure 3 DB calls overall were executed
+      expect(control.log.size).to eq(3)
+      # Ensure memoization value match the raw value above
+      expect(control.count).to eq(control.log.size)
+      # Ensure we have only two sources of queries
+      expect(control.data.keys.size).to eq(2)
+      # Ensure we detect only queries from this file
+      expect(control.data.keys.find_all { |i| i.match(/query_recorder_spec.rb/) }.count).to eq(2)
+    end
+  end
+end