1 files changed, 62 insertions, 0 deletions
diff --git a/scripts/lint/ruby-metrics-abc.rb b/scripts/lint/ruby-metrics-abc.rb
new file mode 100755
index 00000000000..bea7be14a1e
--- /dev/null
+++ b/scripts/lint/ruby-metrics-abc.rb
@@ -0,0 +1,62 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "rubocop"
+
+# Shows ABC size of methods and blocks for passed files.
+#
+# See https://docs.rubocop.org/rubocop/cops_metrics.html#metricsabcsize
+#
+# Usage: scripts/ruby-metrics-abc.rb <ruby file> ...
+#   Example: scripts/ruby-metrics-abc.rb app/models/project.rb app/models/user.rb
+
+module Tooling
+  class MetricsABC
+    extend RuboCop::AST::NodePattern::Macros
+    include RuboCop::AST::Traversal
+
+    def run(source)
+      version = RUBY_VERSION[/^(\d+\.\d+)/, 1].to_f
+      ast = RuboCop::AST::ProcessedSource.new(source, version).ast
+
+      walk(ast)
+    end
+
+    def on_def(node)
+      print_abc("def #{node.method_name}", node)
+    end
+
+    def on_defs(node)
+      print_abc("def self.#{node.method_name}", node)
+    end
+
+    def on_block(node)
+      return unless node.parent&.send_type?
+
+      method_name = node.parent.method_name
+      arguments = node.parent.arguments.select { |n| n.sym_type? || n.str_type? }.map(&:source)
+
+      print_abc("#{method_name}(#{arguments.join(', ')})", node)
+    end
+
+    private
+
+    def print_abc(prefix, node)
+      # https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Metrics/Utils/AbcSizeCalculator#calculate-instance_method
+      abc_score, abc_vector = RuboCop::Cop::Metrics::Utils::AbcSizeCalculator
+        .calculate(node, discount_repeated_attributes: true) # rubocop:disable CodeReuse/ActiveRecord -- This is not AR
+      puts format("  %d: %s: %.2f %s", node.first_line, prefix, abc_score, abc_vector)
+    end
+  end
+
+  if ARGV.empty?
+    puts "Usage: scripts/ruby-metrics-abc.rb <ruby file> ..."
+    puts "  Example: scripts/ruby-metrics-abc.rb app/models/project.rb app/models/user.rb"
+  end
+
+  ARGV.each do |file|
+    puts "Checking #{file}:"
+
+    MetricsABC.new.run(File.read(file))
+  end
+end