Support IgnoredMethod configuration in method complexity cops

CHANGELOG.md

@@ -18,6 +18,7 @@
 * [#7739](https://github.com/rubocop-hq/rubocop/pull/7739): Add `IgnoreNotImplementedMethods` configuration to `Lint/UnusedMethodArgument`. ([@tejasbubane][])
 * [#7740](https://github.com/rubocop-hq/rubocop/issues/7740): Add `AllowModifiersOnSymbols` configuration to `Style/AccessModifierDeclarations`. ([@tejasbubane][])
 * [#7812](https://github.com/rubocop-hq/rubocop/pull/7812): Add auto-correction for `Lint/BooleanSymbol` cop. ([@tejasbubane][])
+* [#7823](https://github.com/rubocop-hq/rubocop/pull/7823): Add `IgnoredMethods` configuration in `Metrics/AbcSize`, `Metrics/CyclomaticComplexity`, and `Metrics/PerceivedComplexity` cops. ([@drenmi][])
 
 ### Bug fixes
 

config/default.yml

@@ -1833,9 +1833,10 @@ Metrics/AbcSize:
     - https://en.wikipedia.org/wiki/ABC_Software_Metric
   Enabled: true
   VersionAdded: '0.27'
-  VersionChanged: '0.66'
+  VersionChanged: '0.81'
   # The ABC size is a calculated magnitude, so this number can be an Integer or
   # a Float.
+  IgnoredMethods: []
   Max: 15
 
 Metrics/BlockLength:
@@ -1875,6 +1876,8 @@ Metrics/CyclomaticComplexity:
                  of test cases needed to validate a method.
   Enabled: true
   VersionAdded: '0.25'
+  VersionChanged: '0.81'
+  IgnoredMethods: []
   Max: 6
 
 Metrics/MethodLength:
@@ -1908,6 +1911,8 @@ Metrics/PerceivedComplexity:
                  human reader.
   Enabled: true
   VersionAdded: '0.25'
+  VersionChanged: '0.81'
+  IgnoredMethods: []
   Max: 7
 
 ################## Migration #############################

lib/rubocop/cop/mixin/method_complexity.rb

@@ -5,15 +5,20 @@ module Cop
     # This module handles measurement and reporting of complexity in methods.
     module MethodComplexity
       include ConfigurableMax
+      include IgnoredMethods
       extend NodePattern::Macros
 
       def on_def(node)
+        return if ignored_method?(node.method_name)
+
         check_complexity(node, node.method_name)
       end
       alias on_defs on_def
 
       def on_block(node)
         define_method?(node) do |name|
+          return if ignored_method?(name)
+
           check_complexity(node, name)
         end
       end

manual/cops_metrics.md

@@ -4,7 +4,7 @@
 
 Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
 --- | --- | --- | --- | ---
-Enabled | Yes | No | 0.27 | 0.66
+Enabled | Yes | No | 0.27 | 0.81
 
 This cop checks that the ABC size of methods is not higher than the
 configured maximum. The ABC size is based on assignments, branches
@@ -15,6 +15,7 @@ and https://en.wikipedia.org/wiki/ABC_Software_Metric.
 
 Name | Default value | Configurable values
 --- | --- | ---
+IgnoredMethods | `[]` | Array
 Max | `15` | Integer
 
 ### References
@@ -89,7 +90,7 @@ Max | `100` | Integer
 
 Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
 --- | --- | --- | --- | ---
-Enabled | Yes | No | 0.25 | -
+Enabled | Yes | No | 0.25 | 0.81
 
 This cop checks that the cyclomatic complexity of methods is not higher
 than the configured maximum. The cyclomatic complexity is the number of
@@ -106,6 +107,7 @@ Loops can be said to have an exit condition, so they add one.
 
 Name | Default value | Configurable values
 --- | --- | ---
+IgnoredMethods | `[]` | Array
 Max | `6` | Integer
 
 ## Metrics/MethodLength
@@ -172,7 +174,7 @@ CountKeywordArgs | `true` | Boolean
 
 Enabled by default | Safe | Supports autocorrection | VersionAdded | VersionChanged
 --- | --- | --- | --- | ---
-Enabled | Yes | No | 0.25 | -
+Enabled | Yes | No | 0.25 | 0.81
 
 This cop tries to produce a complexity score that's a measure of the
 complexity the reader experiences when looking at a method. For that
@@ -204,4 +206,5 @@ end                             # 7 complexity points
 
 Name | Default value | Configurable values
 --- | --- | ---
+IgnoredMethods | `[]` | Array
 Max | `7` | Integer

spec/rubocop/cop/metrics/abc_size_spec.rb

@@ -78,6 +78,34 @@ def method_name
         end
       RUBY
     end
+
+    context 'when method is in list of ignored methods' do
+      let(:cop_config) { { 'Max' => 0, 'IgnoredMethods' => ['foo'] } }
+
+      it 'does not register an offense when defining an instance method' do
+        expect_no_offenses(<<~RUBY)
+          def foo
+            bar.baz(:qux)
+          end
+        RUBY
+      end
+
+      it 'does not register an offense when defining a class method' do
+        expect_no_offenses(<<~RUBY)
+          def self.foo
+            bar.baz(:qux)
+          end
+        RUBY
+      end
+
+      it 'does not register an offense when using `define_method`' do
+        expect_no_offenses(<<~RUBY)
+          define_method :foo do
+            bar.baz(:qux)
+          end
+        RUBY
+      end
+    end
   end
 
   context 'when Max is 2' do

spec/rubocop/cop/metrics/cyclomatic_complexity_spec.rb

@@ -215,6 +215,34 @@ def method_name_2
     end
   end
 
+  context 'when method is in list of ignored methods' do
+    let(:cop_config) { { 'Max' => 0, 'IgnoredMethods' => ['foo'] } }
+
+    it 'does not register an offense when defining an instance method' do
+      expect_no_offenses(<<~RUBY)
+        def foo
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+
+    it 'does not register an offense when defining a class method' do
+      expect_no_offenses(<<~RUBY)
+        def self.foo
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+
+    it 'does not register an offense when using `define_method`' do
+      expect_no_offenses(<<~RUBY)
+        define_method :foo do
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+  end
+
   context 'when Max is 2' do
     let(:cop_config) { { 'Max' => 2 } }
 

spec/rubocop/cop/metrics/perceived_complexity_spec.rb

@@ -230,6 +230,34 @@ def method_name_2
     end
   end
 
+  context 'when method is in list of ignored methods' do
+    let(:cop_config) { { 'Max' => 0, 'IgnoredMethods' => ['foo'] } }
+
+    it 'does not register an offense when defining an instance method' do
+      expect_no_offenses(<<~RUBY)
+        def foo
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+
+    it 'does not register an offense when defining a class method' do
+      expect_no_offenses(<<~RUBY)
+        def self.foo
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+
+    it 'does not register an offense when using `define_method`' do
+      expect_no_offenses(<<~RUBY)
+        define_method :foo do
+          bar.baz(:qux)
+        end
+      RUBY
+    end
+  end
+
   context 'when Max is 2' do
     let(:cop_config) { { 'Max' => 2 } }