[Fix #1167] Fix handling of multi-line parameters in TrailingComma

Hashes and other items spanning more than one line were not handled
correctly when it came to checking if the closing bracket was on
the same line.

CHANGELOG.md

@@ -25,6 +25,7 @@
 * [#1158](https://github.com/bbatsov/rubocop/issues/1158): Fix auto-correction of floating-point numbers. ([@bbatsov][])
 * [#1159](https://github.com/bbatsov/rubocop/issues/1159): Fix checking of `begin`..`end` structures, blocks, and parenthesized expressions in `IndentationWidth`. ([@jonas054][])
 * [#1159](https://github.com/bbatsov/rubocop/issues/1159): More rigid conditions for when `attr` is considered an offense. ([@jonas054][])
+* [#1167](https://github.com/bbatsov/rubocop/issues/1167): Fix handling of parameters spanning multiple lines in `TrailingComma`. ([@jonas054][])
 
 ## 0.23.0 (02/06/2014)
 

lib/rubocop/cop/style/trailing_comma.rb

@@ -114,7 +114,7 @@ def multiline?(node)
         end
 
         def on_same_line?(a, b)
-          [a, b].map(&:line).uniq.size == 1
+          a.line + a.source.count("\n") == b.line
         end
 
         def avoid_comma(kind, comma_begin_pos, sb, extra_info)

spec/rubocop/cop/style/trailing_comma_spec.rb

@@ -160,13 +160,21 @@
     context 'when EnforcedStyleForMultiline is comma' do
       let(:cop_config) { { 'EnforcedStyleForMultiline' => 'comma' } }
 
-      it 'accepts Array literal with no trailing comma when closing bracket ' \
-         'is on same line as last value' do
-        inspect_source(cop, ['VALUES = [',
-                             '           1001,',
-                             '           2020,',
-                             '           3333]'])
-        expect(cop.offenses).to be_empty
+      context 'when closing bracket is on same line as last value' do
+        it 'accepts Array literal with no trailing comma' do
+          inspect_source(cop, ['VALUES = [',
+                               '           1001,',
+                               '           2020,',
+                               '           3333]'])
+          expect(cop.offenses).to be_empty
+        end
+
+        it 'accepts a method call with Hash as last parameter split on ' \
+           'multiple lines' do
+          inspect_source(cop, ['some_method(a: "b",',
+                               '            c: "d")'])
+          expect(cop.offenses).to be_empty
+        end
       end
 
       it 'accepts Array literal with two of the values on the same line' do
@@ -262,7 +270,7 @@
                              "  'auth' => <<-HELP.chomp",
                              '...',
                              'HELP',
-                             '},)']) # We still need a comma after the hash.
+                             '})'])
         expect(cop.offenses).to be_empty
       end
     end