Metrics/LineLength auto-correct breaks line in the wrong place

[jonekdahl]

Hi,

I have enabled auto-correction of Metrics/LineLength that was introduced in 0.68. I have also enabled the other recommended cops that were not enabled by default.

Expected behavior

When I run auto-correct, the code should still be valid Ruby code.

Actual behavior

In one instance, a line break was injected in the middle of an integer literal.

I have re-created the issue in a smaller example and this is the diff:

diff --git a/rubocop_line_length.rb b/rubocop_line_length.rb
index c505caa..01762f0 100644
--- a/rubocop_line_length.rb
+++ b/rubocop_line_length.rb
@@ -1,7 +1,9 @@
 class RubocopLineLength
   def breaks_this_incorrectly
     inventory_rows_to_fix = [
-      InventoryRow.new(year: 2019, week: 30, path: 'publisher_group:123;publisher:456;slot_type:midroll', to_book: 21906),
+      InventoryRow.new(year: 2019, week: 3
+0, path: 'publisher_group:123;
+publisher:456;slot_type:midroll', to_book: 21906),
       InventoryRow.new(year: 2019, week: 31, path: 'publisher_group:123;slot_type:preroll', to_book: 1558)
     ]
   end

Steps to reproduce the problem

Create .rubocop.yml:

Metrics/LineLength:
  AutoCorrect: true

Layout/MultilineArrayLineBreaks:
  Enabled: true

Layout/MultilineHashKeyLineBreaks:
  Enabled: true

Layout/MultilineMethodArgumentLineBreaks:
  Enabled: true

Create rubocop_line_length.rb:

class RubocopLineLength
  def breaks_this_incorrectly
    inventory_rows_to_fix = [
      InventoryRow.new(year: 2019, week: 30, path: 'publisher_group:123;publisher:456;slot_type:midroll', to_book: 21906),
      InventoryRow.new(year: 2019, week: 31, path: 'publisher_group:123;slot_type:preroll', to_book: 1558)
    ]
  end
end

Run rubocop --only Layout,Metrics/LineLength --auto-correct rubocop_line_length.rb

RuboCop version

$ rubocop -V
0.76.0 (using Parser 2.6.5.0, running on ruby 2.6.5 x86_64-linux)

[buehmann]

That's another off-by-one error in Metrics/LineLength (I recently fixed another one): master...buehmann:line-length/7477

The example reveals another bug. With the fix above, the cop autocorrects the lines to

      InventoryRow.new(year: 2019, week: 30, path: 'publisher_group:123;
publisher:456;slot_type:midroll', to_book: 21906),
      InventoryRow.new(year: 2019, week: 31, path: 'publisher_group:123;
slot_type:preroll', to_book: 1558)

i.e. it inserts linebreaks into string literal (after the semicolons).

[maxh]

inserts linebreaks into string literal

Here's a fix for that: #7497

I believe that fixes the off-by-one error as well, by removing the buggy code.