1 files changed, 58 insertions, 0 deletions
diff --git a/rubocop/cop/usage_data/histogram_with_large_table.rb b/rubocop/cop/usage_data/histogram_with_large_table.rb
new file mode 100644
index 00000000000..961773df55c
--- /dev/null
+++ b/rubocop/cop/usage_data/histogram_with_large_table.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module UsageData
+      # This cop checks that histogram method is not used in usage_data.rb files
+      # for models representing large tables, as defined by migration helpers.
+      #
+      # @example
+      #
+      # # bad
+      # histogram(Issue, buckets: 1..100)
+      # histogram(User.active, buckets: 1..100)
+      class HistogramWithLargeTable < RuboCop::Cop::Cop
+        MSG = 'Avoid histogram method on %{model_name}'
+
+        # Match one level const as Issue, Gitlab
+        def_node_matcher :one_level_node, <<~PATTERN
+          (send nil? :histogram
+            `(const {nil? cbase} $_)
+          ...)
+        PATTERN
+
+        # Match two level const as ::Clusters::Cluster, ::Ci::Pipeline
+        def_node_matcher :two_level_node, <<~PATTERN
+          (send nil? :histogram
+            `(const
+              (const {nil? cbase} $_)
+            $_)
+          ...)
+        PATTERN
+
+        def on_send(node)
+          one_level_matches = one_level_node(node)
+          two_level_matches = two_level_node(node)
+
+          return unless Array(one_level_matches).any? || Array(two_level_matches).any?
+
+          class_name = two_level_matches ? two_level_matches.join('::').to_sym : one_level_matches
+
+          if large_table?(class_name)
+            add_offense(node, location: :expression, message: format(MSG, model_name: class_name))
+          end
+        end
+
+        private
+
+        def large_table?(model)
+          high_traffic_models.include?(model.to_s)
+        end
+
+        def high_traffic_models
+          cop_config['HighTrafficModels'] || []
+        end
+      end
+    end
+  end
+end