Deprecate ConfigurableMax in favour of ExcludeLimit which allows …

…multiple configuration options to be added to the exclude limit for `--auto-gen-config`.

docs/modules/ROOT/pages/v1_upgrade_notes.adoc

@@ -254,3 +254,4 @@ Refactored for better separation of concern, being reusable, better result repor
  ** `Cop.registry` \=> `Registry.global`
  ** `Cop.all` \=> `Registry.all`
  ** `Cop.qualified_cop_name` \=> `Registry.qualified_cop_name`
+* The `ConfigurableMax` mixin for tracking exclude limits of configuration options is deprecated. Use `exclude_limit ParameterName` instead.

lib/rubocop.rb

@@ -35,6 +35,7 @@
 require_relative 'rubocop/cop/message_annotator'
 require_relative 'rubocop/cop/ignored_node'
 require_relative 'rubocop/cop/autocorrect_logic'
+require_relative 'rubocop/cop/exclude_limit'
 require_relative 'rubocop/cop/badge'
 require_relative 'rubocop/cop/registry'
 require_relative 'rubocop/cop/base'

lib/rubocop/cop/base.rb

@@ -34,6 +34,7 @@ module Cop
     class Base # rubocop:disable Metrics/ClassLength
       extend RuboCop::AST::Sexp
       extend NodePattern::Macros
+      extend ExcludeLimit
       include RuboCop::AST::Sexp
       include Util
       include IgnoredNode

lib/rubocop/cop/exclude_limit.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module RuboCop
+  # Allows specified configuration options to have an exclude limit
+  # ie. a maximum value tracked that it can be used by `--auto-gen-config`.
+  module ExcludeLimit
+    # Sets up a configuration option to have an exclude limit tracked.
+    # The parameter name given is transformed into a method name (eg. `Max`
+    # becomes `self.max=` and `MinDigits` becomes `self.min_digits=`).
+    def exclude_limit(parameter_name, method_name: transform(parameter_name))
+      define_method("#{method_name}=") do |value|
+        cfg = config_to_allow_offenses
+        cfg[:exclude_limit] ||= {}
+        current_max = cfg[:exclude_limit][parameter_name]
+        value = [current_max, value].max if current_max
+        cfg[:exclude_limit][parameter_name] = value
+      end
+    end
+
+    private
+
+    def transform(parameter_name)
+      parameter_name.gsub(/(?<!\A)(?=[A-Z])/, '_').downcase
+    end
+  end
+end

lib/rubocop/cop/layout/line_length.rb

@@ -60,12 +60,13 @@ module Layout
       #   }
       class LineLength < Base
         include CheckLineBreakable
-        include ConfigurableMax
         include IgnoredPattern
         include RangeHelp
         include LineLengthHelp
         extend AutoCorrector
 
+        exclude_limit 'Max'
+
         MSG = 'Line is too long. [%<length>d/%<max>d]'
 
         def on_block(node)

lib/rubocop/cop/metrics/block_nesting.rb

@@ -12,13 +12,13 @@ module Metrics
       #
       # The maximum level of nesting allowed is configurable.
       class BlockNesting < Base
-        include ConfigurableMax
-
         NESTING_BLOCKS = %i[
           case if while while_post
           until until_post for resbody
         ].freeze
 
+        exclude_limit 'Max'
+
         def on_new_investigation
           return if processed_source.blank?
 

lib/rubocop/cop/metrics/parameter_lists.rb

@@ -51,7 +51,8 @@ module Metrics
       #   end
       #
       class ParameterLists < Base
-        include ConfigurableMax
+        exclude_limit 'Max'
+
 
         MSG = 'Avoid parameter lists longer than %<max>d parameters. ' \
               '[%<count>d/%<max>d]'

lib/rubocop/cop/mixin/code_length.rb

@@ -4,10 +4,12 @@ module RuboCop
   module Cop
     # Common functionality for checking length of code segments.
     module CodeLength
-      include ConfigurableMax
+      extend ExcludeLimit
 
       MSG = '%<label>s has too many lines. [%<length>d/%<max>d]'
 
+      exclude_limit 'Max'
+
       private
 
       def message(length, max_length)

lib/rubocop/cop/mixin/configurable_max.rb

@@ -4,6 +4,7 @@ module RuboCop
   module Cop
     # Handles `Max` configuration parameters, especially setting them to an
     # appropriate value with --auto-gen-config.
+    # @deprecated Use `exclude_limit ParameterName` instead.
     module ConfigurableMax
       private
 

lib/rubocop/cop/mixin/method_complexity.rb

@@ -6,10 +6,12 @@ module Cop
     #
     # This module handles measurement and reporting of complexity in methods.
     module MethodComplexity
-      include ConfigurableMax
       include IgnoredMethods
       include Metrics::Utils::RepeatedCsendDiscount
       extend NodePattern::Macros
+      extend ExcludeLimit
+
+      exclude_limit 'Max'
 
       # Ensure cops that include `MethodComplexity` have the config
       # `attr_accessor`s that `ignored_method?` needs.

lib/rubocop/cop/style/numeric_literals.rb

@@ -28,17 +28,18 @@ module Style
       #   10_000_00 # typical representation of $10,000 in cents
       #
       class NumericLiterals < Base
-        # The parameter is called MinDigits (meaning the minimum number of
-        # digits for which an offense can be registered), but essentially it's
-        # a Max parameter (the maximum number of something that's allowed).
-        include ConfigurableMax
         include IntegerNode
         extend AutoCorrector
 
         MSG = 'Use underscores(_) as thousands separator and ' \
               'separate every 3 digits with them.'
         DELIMITER_REGEXP = /[eE.]/.freeze
 
+        # The parameter is called MinDigits (meaning the minimum number of
+        # digits for which an offense can be registered), but essentially it's
+        # a Max parameter (the maximum number of something that's allowed).
+        exclude_limit 'MinDigits'
+
         def on_int(node)
           check(node)
         end
@@ -49,10 +50,6 @@ def on_float(node)
 
         private
 
-        def max_parameter_name
-          'MinDigits'
-        end
-
         def check(node)
           int = integer_part(node)
 
@@ -62,7 +59,7 @@ def check(node)
 
           case int
           when /^\d+$/
-            return unless (self.max = int.size + 1)
+            return unless (self.min_digits = int.size + 1)
 
             register_offense(node)
           when /\d{4}/, short_group_regex