Use runtime matchers for hooks

In order to make matchers be able to fetch hooks from configuration.

Author: sl4vr

lib/rubocop/cop/rspec/described_class.rb

@@ -64,8 +64,9 @@ class DescribedClass < Cop
           (block (send (const nil? {:Class :Module :Struct}) :new ...) ...)
         PATTERN
 
-        def_node_matcher :rspec_block?,
-                         RuboCop::RSpec::Language::ALL.block_pattern
+        def_runtime_node_matcher :rspec_block? do
+          all_selectors.block_pattern
+        end
 
         def_node_matcher :scope_changing_syntax?, '{def class module}'
 

lib/rubocop/cop/rspec/dialect.rb

@@ -46,7 +46,9 @@ class Dialect < Cop
 
         MSG = 'Prefer `%<prefer>s` over `%<current>s`.'
 
-        def_node_matcher :rspec_method?, ALL.send_pattern
+        def_runtime_node_matcher :rspec_method? do
+          all_selectors.send_pattern
+        end
 
         def on_send(node)
           return unless rspec_method?(node)

lib/rubocop/cop/rspec/empty_hook.rb

@@ -27,14 +27,11 @@ class EmptyHook < Cop
 
         MSG = 'Empty hook detected.'
 
-        def_node_matcher :empty_hook?, <<~PATTERN
-          (block $#{Hooks::ALL.send_pattern} _ nil?)
-        PATTERN
-
         def on_block(node)
-          empty_hook?(node) do |hook|
-            add_offense(hook)
-          end
+          return unless hook?(node)
+          return unless node.body.nil?
+
+          add_offense(node.send_node)
         end
 
         def autocorrect(node)

lib/rubocop/cop/rspec/hook_argument.rb

@@ -64,13 +64,15 @@ class HookArgument < Cop
                        'argument for RSpec hooks.'
         EXPLICIT_MSG = 'Use `%<scope>p` for RSpec hooks.'
 
-        HOOKS = Hooks::ALL.node_pattern_union.freeze
-
-        def_node_matcher :scoped_hook, <<-PATTERN
-          (block $(send _ #{HOOKS} (sym ${:each :example})) ...)
-        PATTERN
+        def_runtime_node_matcher :scoped_hook do
+          <<-PATTERN
+            (block $(send _ #{hook_selectors.node_pattern_union} (sym ${:each :example})) ...)
+          PATTERN
+        end
 
-        def_node_matcher :unscoped_hook, "(block $(send _ #{HOOKS}) ...)"
+        def_runtime_node_matcher :unscoped_hook do
+          "(block $(send _ #{hook_selectors.node_pattern_union}) ...)"
+        end
 
         def on_block(node)
           hook(node) do |method_send, scope_name|

lib/rubocop/cop/rspec/named_subject.rb

@@ -45,12 +45,14 @@ class NamedSubject < Cop
         MSG = 'Name your test subject if you need '\
               'to reference it explicitly.'
 
-        def_node_matcher :rspec_block?, <<-PATTERN
-          {
-            #{Examples::ALL.block_pattern}
-            #{Hooks::ALL.block_pattern}
-          }
-        PATTERN
+        def_runtime_node_matcher :rspec_block? do
+          <<-PATTERN
+            {
+              #{Examples::ALL.block_pattern}
+              #{hook_selectors.block_pattern}
+            }
+          PATTERN
+        end
 
         def_node_matcher :shared_example?, <<-PATTERN
           #{SharedGroups::EXAMPLES.block_pattern}

lib/rubocop/cop/rspec/shared_context.rb

@@ -59,9 +59,14 @@ class SharedContext < Cop
 
         examples = (Examples::ALL + Includes::EXAMPLES)
         def_node_search :examples?, examples.send_pattern
-
-        context = (Hooks::ALL + Helpers::ALL + Includes::CONTEXT + Subject::ALL)
-        def_node_search :context?, context.send_pattern
+        def_runtime_node_search :context? do
+          (
+            hook_selectors    +
+            Helpers::ALL      +
+            Includes::CONTEXT +
+            Subject::ALL
+          ).send_pattern
+        end
 
         def_node_matcher :shared_context, SharedGroups::CONTEXT.block_pattern
         def_node_matcher :shared_example, SharedGroups::EXAMPLES.block_pattern

lib/rubocop/rspec/language.rb

@@ -91,17 +91,15 @@ module Examples
       end
 
       module Hooks
-        ALL = SelectorSet.new(
-          %i[
-            prepend_before
-            before
-            append_before
-            around
-            prepend_after
-            after
-            append_after
-          ]
-        )
+        BUILT_IN_METHOD_NAMES = %i[
+          prepend_before
+          before
+          append_before
+          around
+          prepend_after
+          after
+          append_after
+        ].freeze
 
         module Scopes
           ALL = SelectorSet.new(
@@ -131,16 +129,6 @@ module Expectations
       module Runners
         ALL = SelectorSet.new(%i[to to_not not_to])
       end
-
-      ALL =
-        ExampleGroups::ALL +
-        SharedGroups::ALL  +
-        Examples::ALL      +
-        Hooks::ALL         +
-        Helpers::ALL       +
-        Subject::ALL       +
-        Expectations::ALL  +
-        Runners::ALL
     end
   end
 end

lib/rubocop/rspec/language/node_pattern.rb

@@ -20,11 +20,35 @@ module NodePattern
 
         def_node_matcher :example?, Examples::ALL.block_pattern
 
-        def_node_matcher :hook?, Hooks::ALL.block_pattern
-
         def_node_matcher :let?, Helpers::ALL.block_or_block_pass_pattern
 
         def_node_matcher :subject?, Subject::ALL.block_pattern
+
+        def_runtime_node_matcher :hook? do
+          hook_selectors.block_pattern
+        end
+
+        def hook_selectors
+          custom_method_names = config
+            .for_all_cops
+            .fetch('RSpec', {})
+            .fetch('Language', {})
+            .fetch('Hooks', [])
+            .map(&:to_sym)
+
+          SelectorSet.new(Hooks::BUILT_IN_METHOD_NAMES + custom_method_names)
+        end
+
+        def all_selectors
+          ExampleGroups::ALL  +
+            SharedGroups::ALL +
+            Examples::ALL     +
+            hook_selectors    +
+            Helpers::ALL      +
+            Subject::ALL      +
+            Expectations::ALL +
+            Runners::ALL
+        end
       end
     end
   end