[Fix rubocop#3696] modified empty_when lint to not warn when branches…

… when body has comments
hanumakanthvvn · Nov 15, 2016 · 8b3f72e · 8b3f72e
1 parent b7f224b
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Showing 3 changed files with 22 additions and 10 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -17,6 +17,7 @@
 
 * [#3662](https://github.com/bbatsov/rubocop/issues/3662): Fix the auto-correction of `Lint/UnneededSplatExpansion` when the splat expansion is inside of another array. ([@rrosenblum][])
 * [#3699](https://github.com/bbatsov/rubocop/issues/3699): Fix false positive in `Style/VariableNumber` on variable names ending with an underscore. ([@bquorning][])
+* [#3696](https://github.com/bbatsov/rubocop/issues/3696): Fix to avoid warning `when` branches without a body if it has comments. ([@hanumakanthvvn][])
 
 ## 0.45.0 (2016-10-31)
 
@@ -2492,3 +2493,4 @@
 [@iGEL]: https://github.com/iGEL
 [@tessi]: https://github.com/tessi
 [@ivanovaleksey]: https://github.com/ivanovaleksey
+[@hanumakanthvvn]: https://github.com/hanumakanthvvn
diff --git a/lib/rubocop/cop/lint/empty_when.rb b/lib/rubocop/cop/lint/empty_when.rb
@@ -15,6 +15,10 @@ module Lint
       class EmptyWhen < Cop
         MSG = 'Avoid `when` branches without a body.'.freeze
 
+        def investigate(processed_source)
+          @processed_source = processed_source
+        end
+
         def on_case(node)
           _cond_node, *when_nodes, _else_node = *node
 
@@ -27,12 +31,12 @@ def on_case(node)
 
         def check_when(when_node)
           return unless empty_when_body?(when_node)
-
           add_offense(when_node, when_node.source_range, MSG)
         end
 
         def empty_when_body?(when_node)
-          !when_node.to_a.last
+          node_comment = @processed_source[when_node.loc.first_line]
+          !(when_node.to_a.last || comment_line?(node_comment))
         end
       end
     end

diff --git a/spec/rubocop/cop/lint/empty_when_spec.rb b/spec/rubocop/cop/lint/empty_when_spec.rb
@@ -44,26 +44,26 @@
     it_behaves_like 'code with offense',
                     ['case foo',
                      'when :bar then 1',
-                     'when :baz # nothing',
+                     'when :baz',
                      'end'].join("\n")
 
     it_behaves_like 'code with offense',
                     ['case foo',
                      'when :bar then 1',
                      'when :baz # nothing',
-                     'else 3',
+                     'else',
                      'end'].join("\n")
 
     it_behaves_like 'code with offense',
                     ['case foo',
                      'when :bar then 1',
-                     'when :baz then # nothing',
+                     'when :baz then',
                      'end'].join("\n")
 
     it_behaves_like 'code with offense',
                     ['case foo',
                      'when :bar then 1',
-                     'when :baz then # nothing',
+                     'when :baz then',
                      'else 3',
                      'end'].join("\n")
 
@@ -72,25 +72,22 @@
                      'when :bar',
                      '  1',
                      'when :baz',
-                     '  # nothing',
                      'end'].join("\n")
 
     it_behaves_like 'code with offense',
                     ['case foo',
                      'when :bar',
                      '  1',
                      'when :baz',
-                     '  # nothing',
+                     '  ',
                      'else',
-                     '  3',
                      'end'].join("\n")
 
     it_behaves_like 'code with offense',
                     ['case',
                      'when :bar',
                      '  1',
                      'when :baz',
-                     '  # nothing',
                      'else',
                      '  3',
                      'end'].join("\n")
@@ -136,5 +133,14 @@
                      'else',
                      '  3',
                      'end'].join("\n")
+    it_behaves_like 'code without offense',
+                    ['case',
+                     'when :bar',
+                     '  1',
+                     'when :baz',
+                     '  # nothing',
+                     'else',
+                     '  3',
+                     'end'].join("\n")
   end
 end