Unify empty line cop logic

- DRYs things up a bit.
- Ensures each cop correctly handles heredocs.
- Unifies highlighting format.
  * Note: It was very hard to find some sort of unified way to highlight
    the different possible node endings, so I just went with
    highlighting the lowest offending line starting right of any
    whitespace.
- Ensures each cop allows comments immediately following the offending
  line, notably to provide support for rubocop:disable directives
  (especially disable/enable pairs that might surround the block).

lib/rubocop-rspec.rb

@@ -21,6 +21,7 @@
 require_relative 'rubocop/rspec/capybara'
 require_relative 'rubocop/rspec/factory_bot'
 require_relative 'rubocop/rspec/final_end_location'
+require_relative 'rubocop/rspec/blank_line_separation'
 
 RuboCop::RSpec::Inject.defaults!
 

lib/rubocop/cop/rspec/empty_line_after_example_group.rb

@@ -24,6 +24,8 @@ module RSpec
       #   end
       #
       class EmptyLineAfterExampleGroup < Cop
+        include RuboCop::RSpec::BlankLineSeparation
+
         MSG = 'Add an empty line after `%<example_group>s`.'.freeze
 
         def_node_matcher :example_group, ExampleGroups::ALL.block_pattern
@@ -32,24 +34,13 @@ def on_block(node)
           return unless example_group(node)
           return if node.parent && node.equal?(node.parent.children.last)
 
-          return if next_line(node).blank?
-
-          add_offense(
-            node,
-            location: node.loc.end,
-            message: format(MSG, example_group: node.method_name)
-          )
-        end
-
-        def autocorrect(node)
-          ->(corrector) { corrector.insert_after(node.loc.end, "\n") }
-        end
-
-        private
-
-        def next_line(node)
-          send_line = node.loc.end.line
-          processed_source[send_line]
+          missing_separating_line(node) do |location|
+            add_offense(
+              node,
+              location: location,
+              message: format(MSG, example_group: node.method_name)
+            )
+          end
         end
       end
     end

lib/rubocop/cop/rspec/empty_line_after_final_let.rb

@@ -17,8 +17,7 @@ module RSpec
       #
       #   it { does_something }
       class EmptyLineAfterFinalLet < Cop
-        include RangeHelp
-        include RuboCop::RSpec::FinalEndLocation
+        include RuboCop::RSpec::BlankLineSeparation
 
         MSG = 'Add an empty line after the last `let` block.'.freeze
 
@@ -32,39 +31,10 @@ def on_block(node)
           return if latest_let.nil?
           return if latest_let.equal?(node.body.children.last)
 
-          no_new_line_after(latest_let) do |location|
+          missing_separating_line(latest_let) do |location|
             add_offense(latest_let, location: location)
           end
         end
-
-        def autocorrect(node)
-          lambda do |corrector|
-            no_new_line_after(node) do |location|
-              corrector.insert_after(location.end, "\n")
-            end
-          end
-        end
-
-        private
-
-        def no_new_line_after(node)
-          line = final_end_location(node).line
-          line += 1 while comment_line?(processed_source[line])
-
-          return if processed_source[line].blank?
-          yield offending_loc(node, line)
-        end
-
-        def offending_loc(node, last_line)
-          offending_line = processed_source[last_line - 1]
-          if comment_line?(offending_line)
-            start = offending_line.index('#')
-            length = offending_line.length - start
-            source_range(processed_source.buffer, last_line, start, length)
-          else
-            node.loc.expression
-          end
-        end
       end
     end
   end

lib/rubocop/cop/rspec/empty_line_after_hook.rb

@@ -34,6 +34,8 @@ module RSpec
       #   it { does_something }
       #
       class EmptyLineAfterHook < Cop
+        include RuboCop::RSpec::BlankLineSeparation
+
         MSG = 'Add an empty line after `%<hook>s`.'.freeze
 
         def_node_matcher :hook?, Hooks::ALL.block_pattern
@@ -42,24 +44,13 @@ def on_block(node)
           return unless hook?(node)
           return if node.equal?(node.parent.children.last)
 
-          return if next_line(node).blank?
-
-          add_offense(
-            node,
-            location: :expression,
-            message: format(MSG, hook: node.method_name)
-          )
-        end
-
-        def autocorrect(node)
-          ->(corrector) { corrector.insert_after(node.loc.end, "\n") }
-        end
-
-        private
-
-        def next_line(node)
-          send_line = node.loc.end.line
-          processed_source[send_line]
+          missing_separating_line(node) do |location|
+            add_offense(
+              node,
+              location: location,
+              message: format(MSG, hook: node.method_name)
+            )
+          end
         end
       end
     end

lib/rubocop/cop/rspec/empty_line_after_subject.rb

@@ -15,6 +15,8 @@ module RSpec
       #
       #   let(:foo) { bar }
       class EmptyLineAfterSubject < Cop
+        include RuboCop::RSpec::BlankLineSeparation
+
         MSG = 'Add empty line after `subject`.'.freeze
 
         def_node_matcher :subject?, Subject::ALL.block_pattern
@@ -23,15 +25,9 @@ def on_block(node)
           return unless subject?(node) && !in_spec_block?(node)
           return if node.equal?(node.parent.children.last)
 
-          send_line = node.loc.end.line
-          next_line = processed_source[send_line]
-          return if next_line.blank?
-
-          add_offense(node, location: :expression, message: MSG)
-        end
-
-        def autocorrect(node)
-          ->(corrector) { corrector.insert_after(node.loc.end, "\n") }
+          missing_separating_line(node) do |location|
+            add_offense(node, location: location, message: MSG)
+          end
         end
 
         private

lib/rubocop/rspec/blank_line_separation.rb

@@ -0,0 +1,37 @@
+module RuboCop
+  module RSpec
+    # Helps determine the offending location if there is not a blank line
+    # following the node. Allows comments to follow directly after.
+    module BlankLineSeparation
+      include FinalEndLocation
+      include RuboCop::Cop::RangeHelp
+
+      def missing_separating_line(node)
+        line = final_end_location(node).line
+
+        line += 1 while comment_line?(processed_source[line])
+
+        return if processed_source[line].blank?
+
+        yield offending_loc(line)
+      end
+
+      def offending_loc(last_line)
+        offending_line = processed_source[last_line - 1]
+
+        content_length = offending_line.lstrip.length
+        start          = offending_line.length - content_length
+
+        source_range(processed_source.buffer, last_line, start, content_length)
+      end
+
+      def autocorrect(node)
+        lambda do |corrector|
+          missing_separating_line(node) do |location|
+            corrector.insert_after(location.end, "\n")
+          end
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/rspec/empty_line_after_example_group_spec.rb

@@ -15,6 +15,17 @@
     RUBY
   end
 
+  it 'highlights single line formulations correctly' do
+    expect_offense(<<-RUBY)
+      RSpec.describe Foo do
+        describe('#bar') { }
+        ^^^^^^^^^^^^^^^^^^^^ Add an empty line after `describe`.
+        describe '#baz' do
+        end
+      end
+    RUBY
+  end
+
   it 'checks for empty line after context' do
     expect_offense(<<-RUBY)
       RSpec.context 'foo' do

spec/rubocop/cop/rspec/empty_line_after_final_let_spec.rb

@@ -19,9 +19,9 @@
       RSpec.describe User do
         let(:a) { a }
         let!(:b) do
-        ^^^^^^^^^^^ Add an empty line after the last `let` block.
           b
         end
+        ^^^ Add an empty line after the last `let` block.
         it { expect(a).to eq(b) }
       end
     RUBY
@@ -143,6 +143,21 @@
     RUBY
   end
 
+  it 'handles silly HEREDOC offense' do
+    expect_offense(<<-RUBY)
+      RSpec.describe 'silly heredoc syntax' do
+        let(:foo) { <<-BAR }
+        hello
+        world
+        BAR
+        ^^^ Add an empty line after the last `let` block.
+        it 'has tricky syntax' do
+          expect(foo).to eql("  hello\n  world\n")
+        end
+      end
+    RUBY
+  end
+
   bad_example = <<-RUBY
   RSpec.describe User do
     let(:params) { foo }
@@ -185,6 +200,31 @@
   end
   RUBY
 
+  include_examples 'autocorrect',
+                   bad_example,
+                   good_example
+
+  bad_example = <<-RUBY
+  RSpec.describe User do
+    let(:params) { <<-DOC }
+     I'm super annoying!
+    DOC
+    it 'has a new line' do
+    end
+  end
+  RUBY
+
+  good_example = <<-RUBY
+  RSpec.describe User do
+    let(:params) { <<-DOC }
+     I'm super annoying!
+    DOC
+
+    it 'has a new line' do
+    end
+  end
+  RUBY
+
   include_examples 'autocorrect',
                    bad_example,
                    good_example